The isolated hydrophilic black alder(Alnus glutinosa)bark extractives were characterized in terms of component and functional composition and converted at 150℃-170℃ into liquid green polyols using solvent-free and l...The isolated hydrophilic black alder(Alnus glutinosa)bark extractives were characterized in terms of component and functional composition and converted at 150℃-170℃ into liquid green polyols using solvent-free and lowtoxic base-catalyzed modification with propylene carbonate(PC).FTIR spectroscopy,HP-LC,GC,GPC,and wet chemistry methods were used to characterize the starting constituents,intermediate and final products of the reaction and to monitor the different pathways of PC conversion.The reaction of extractives as well as the model compounds,including catechol,xylose,PEG 400,and benzoic acid,with PC indicated the ability of OH groups of different origins present in the extractives to condense with equivalent amounts of PC.The polyols obtained consist of a copolymer fraction with one oxypropyl unit grafted per OH functionality of extractive components on average and oligo oxypropyl diols with a small number of carbonate linkages in the chain,obtained as a result of remaining PC homopolymerization.The domination of the oxypropylation mechanism vs.transcarbonation for PC ring opening was observed for both copolymerization and homopolymerization processes,making the process of oxypropylation with PC similar to that of conventional oxypropylation.At optimal reaction conditions,including a PC/OH ratio of 3.0 and a 24-h duration at 150°C,uniform polyols with low viscosity of~900 mPa·s^(-1),a biomass content of~27%,and an OHV of~500 mg KOH·g^(-1) were obtained.Increasing the temperature of modification allows shortening the process but drastically increases the polyol viscosity.At fixed temperature values,increasing the PC/OH ratio not only decreases the biomass content but also strongly prolongs the processing.The significantly increased duration of the process using PC as an alternative oxyalkylation agent compared to that of oxyalkylation with propylene oxide is a reasonable trade-off for using a safer and more environmentally friendly technology.展开更多
The activities of nickel supported on MCM-41 catalysts, prepared by co-impregnation with polyols （ethylene glycol, glycerol, xylitol, sorbitol and glucose）, were investigated by hydrogenation of naphthalene. Compare...The activities of nickel supported on MCM-41 catalysts, prepared by co-impregnation with polyols （ethylene glycol, glycerol, xylitol, sorbitol and glucose）, were investigated by hydrogenation of naphthalene. Compared with the conventional wetness impregnation, addition of moderate polyols into the metal nitrate support surface, resulting in formation of persion of the active phase and significant aqueous solution could enhance interaction with very small NiO particle size （〈5 nm）, high discatalytic activity. Particle size of Ni^0 decreased from 36.1 nm to below 5 nm; meanwhile the complete hydrogenation of naphthalene was dependent on the Ni^0 particle size. The hydrogenation activities of the catalysts prepared by co-impregnation with polyols were very high with 100% conversion even at iow temperature of 55 ℃.展开更多
In the present study we report on changes in irritable bowel syndrome-severity scoring system (IBS-SSS) and irritable bowel syndrome-quality of life (IBS-QoL) in 19 IBS patients, aged 18 to 74 years (F/M: 14/5), durin...In the present study we report on changes in irritable bowel syndrome-severity scoring system (IBS-SSS) and irritable bowel syndrome-quality of life (IBS-QoL) in 19 IBS patients, aged 18 to 74 years (F/M: 14/5), during 12 wk registering their symptoms on the web-application (www.ibs.constant-care.dk). During a control period of the first 6-wk patients were asked to register their IBS-SSS and IBS-QoL on the web-application weekly without receiving any intervention. Thereafter, low fermentable oligo-, di-, mono-saccharides and polyols (FODMAP) diet (LFD) was introduced for the next 6 wk while continuing the registration. Though a small sample size a significant improvement in disease activity (IBS-SSS) was observed during both the control period, median: 278 (range: 122-377), P = 0.02, and subsequently during the LFD period, median: 151 (range: 29-334), P < 0.01. The IBS-QoL solely changed significantly during the LFD period, median: 67 (37-120), P < 0.01. The significant reduction in disease activity during the control period shows a positive effect of the web-application on IBS symptoms when presented as a “traffic light”. However adding the diet reduced IBS-SSS to < 150, inactive to mild symptoms. In the future results from larger scale trials are awaited.展开更多
Three kinds of tung oil-based structural flame retardants polyols(TOFPs) were prepared by new methods in this paper. First, tung oil was used to produce monoglyceride and diglyceride by transesterification with glycer...Three kinds of tung oil-based structural flame retardants polyols(TOFPs) were prepared by new methods in this paper. First, tung oil was used to produce monoglyceride and diglyceride by transesterification with glycerol by sodium methoxide. The products after transesterification were epoxidized by peracetic acid which was in-situ generated from acetic acid and hydrogen peroxide in the presence of sulfuric acid catalyst. And then, TOFPs were prepared from epoxidized alcoholysis tung oil(EGTO) with 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide(DOPO), diethyl phosphate(DEP) and diethanolamine(DEA) by ring-opening reactions, respectively. GPC was used to evaluate the conversion rate, at optimum reaction conditions, selectivity for monoglyceride in transesterification. The influence of different parameters such as temperature, mole ratio or mass ratio on the conversion rate of transesterification and epoxidation were investigated. The molecular structures of TOFPs were characterized by FTIR and ~1HNMR. Finally, tung oil-based polyurethane foams(TOPUFs) were prepared by a one-shot process using TOFPs with polyisocyanate. The LOI values of TOPUFs whose content of DOPO-EGTO,DEP-EGTO and DEA-EGTO were 100 wt% can reach to 26.2%, 25.1%, and 24.4%, respectively.展开更多
A series of self-reducing bifunctional Ni-W/SBA-15 catalysts were synthesized using biomass-based carbon source as the reducing agent without conventional further reduction step. The self-reducing catalysts were perfo...A series of self-reducing bifunctional Ni-W/SBA-15 catalysts were synthesized using biomass-based carbon source as the reducing agent without conventional further reduction step. The self-reducing catalysts were performed on the hydrogenolysis of cellulose to low carbon polyols. The effects of calcination temperature and metallic loading contents for cellulose hydrogenolysis reaction were investigated detailedly.The optimal calcination temperature was found to be 673 K by TG analysis. The active metal nanoparticles with a better dispersion were observed using SEM and element mapping technology. The yield of low carbon polyols using the catalyst with the receipt of 10%Ni-15%W/SBA-15-673 K can reach as high as68.14%, of which the ethylene glycol(EG) accounts for 61.04%.展开更多
Recently, hyperbranched polymers(HBPs), which differ significantly in structure and properties from linear, cross-linked and branched analogs, have become increasingly important. HBP have a spatial unloaded core and a...Recently, hyperbranched polymers(HBPs), which differ significantly in structure and properties from linear, cross-linked and branched analogs, have become increasingly important. HBP have a spatial unloaded core and a shell of branched monomer units(dendrons), in which functional groups are predominantly located in the surface layer. The size of macromolecules ranges from 2 nm to 100 nm. Currently, there are a fairly large number of publications in the literature devoted to the modification of hyperbranched polyester polyols with various functional groups and the assessment of the potential for their use. However, there are no review articles on this topic in recent years. In this regard, it is relevant to generalize the latest achievements in the field of synthesis, properties and application of hyperbranched polyester polyols with terminal oxygen, nitrogen, silicon, sulfur and organophosphorus fragments. The advantage of hyperbranched polyester polyols of the Boltorn H series is their industrial availability, biodegradability, nanoscale, non-toxicity and high solubility in various polar solvents due to short monomer units, as well as the presence of reactive terminal hydroxyl groups. Functionalization of hyperbranched polyester polyols at hydroxyl groups is mainly carried out by addition of acid anhydrides, iso(thio)cyanates, alkenes, lactides, lactones, lactams, epoxy compounds or reactions with halogenated compounds(alkyl halides, acid chlorides). In some cases, for the functionalization of polyester polyols special linkers are used, such as acid chlorides of unsaturated or dicarboxylic acids, diisocyanates, etc., which provide covalent bonding of the hyperbranched polymer with the target functional group. The obtained derivatives of hyperbranched polyesters are widely used in such areas as biomedicine, pharmacy, paints and varnishes, they are also used as catalysts, membranes, multifunctional coatings, plasticizers and polymer stabilizers.展开更多
Phosphate material LiMnPO4 is popular for its high energy density(697 W·h·kg^(-1))and safety.When LiMnPO_(4) crystal grows,the potential barrier along b and c axis is strong,which makes the crystal grow alon...Phosphate material LiMnPO4 is popular for its high energy density(697 W·h·kg^(-1))and safety.When LiMnPO_(4) crystal grows,the potential barrier along b and c axis is strong,which makes the crystal grow along b axis to form a one-dimensional chain structure.However,the main migration channel of lithium ions in olivine structure is plane(010).By shortening the growth in the direction of b axis and enhancing the diffusion along the directions of a and c,two-dimensional nanosheets that are more conducive to the migration of lithium ions are formed.The dosage of polyols is the key factor guiding the dispersion of the crystals to the(010)plane.X-ray diffraction(XRD),Scanning electron microscopy(SEM),transmission electron microscopy(TEM)and other means are used to characterize the samples.After experiments,we found that when the ratio of polyol/water was 2:1,the morphology of the synthesized sample was 20–30 nm thick nanosheets,which had the best electrochemical performance.At 0.1C,the discharge specific capacity reaches 148.9 mA·h·g^(-1),still reaches 144.3 mA·h·g^(-1) at the 50th cycle.and there is still 112.5 mA·h·g^(-1) under high rate(5C).This is thanks to the good dispersion of the material in the direction of the crystal plane(010).This can solve the problem of low conductivity and ionic mobility of phosphate materials.展开更多
This work proved that biomass-based polyols (sorbitol, xylitol, erythritol, glycerol and ethanediol) were able to be converted into high-value chemical (p-xylene) by catalytic cracking of polyols, alkylation of aromat...This work proved that biomass-based polyols (sorbitol, xylitol, erythritol, glycerol and ethanediol) were able to be converted into high-value chemical (p-xylene) by catalytic cracking of polyols, alkylation of aromatics, and the isomerization of xylenes over the SiO2-modified zeolites. Compared to the conventional HZSM-5 zeolite, the SiO2-containing zeolites considerably increased the selectivity and yield of p-xylene due to the reduction of external surface acidity and the narrowing of pore entrance. The influences of the methanol additive, reaction temperature, and types of polyols on the selectivity and yield of p-xylene were investigated in detail. Catalytic cracking of polyols with methanol significantly enhanced the production of p-xylene by the alkylation of toluene with methanol. The highest p-xylene yield of 10.9 C-mol% with a p-xylene/xylenes ratio of 91.1% was obtained over the 15wt%SiO2/HZSM-5 catalyst. The reaction pathway for the formation of p-xylene was addressed according to the study of the key reactions and the characterization of catalysts.展开更多
Catalytic conversion of glucose, the most abundant carbohydrate, to chemicals of petroleum origin has great desirability in terms of sustainability and industrial implementation. In this work, we attempted to exploit ...Catalytic conversion of glucose, the most abundant carbohydrate, to chemicals of petroleum origin has great desirability in terms of sustainability and industrial implementation. In this work, we attempted to exploit the vanadium-based catalysts with high retro-aldol condensation(RAC) activity for the synthesis of small polyols from glucose. Vanadium species incorporated or anchored beta zeolites were found to work effectively in synergy with 1 Ru/AC to produce hydroxyacetone(HA) as the major product(34%)in a semi-continuously stirred tank reactor under 5% glucose concentration. Catalyst characterization by UV-vis and Raman spectral analysis revealed vanadium species mainly stayed in the incorporated form(tetrahedral) at 0.5% of loading and in the supported form(octahedral) at higher loadings up to 8%. Pyridine infrared spectra and temperature programmed desorption of NH3 revealed weak Lewis acid sites in dominance. Vanadium species in the catalysts displayed multiple catalytic roles(isomerization and RAC reaction, and synergism with the hydrogenation catalyst) in the synthesis of HA from glucose. Structureactivity correlation pointed out that the catalytic activity of vanadium species is not dependent on it coordination status, nevertheless, the adjacent vanadium atoms could possibly improve the isomerization rate over the RAC rate in favor of high yield of HA. The catalyst system is recyclable to at least five times without any considerable loss in its activity and structural integrity. The results presented here provide a promising route for the sustainable production of HA and polyols from carbohydrates by using a highly selective vanadium catalyst.展开更多
Advanced wound dressings are replaced traditional dressings in order to provide appropriate environment for healing and also to promote cell migration[1].The key characteristics of wound dressings are non-toxic,highly...Advanced wound dressings are replaced traditional dressings in order to provide appropriate environment for healing and also to promote cell migration[1].The key characteristics of wound dressings are non-toxic,highly absorbed,air permeable,biocompatible and have good mechanical properties[2].Due to providing moist environment and also protecting maceration at the wound edge area,foam dressings are used in various clinical applications[3].They are mostly prepared from polyurethane between polyols and isocyanate polymerization.展开更多
Affinity membranes are fabricated for boric acid removal by the surface functionalization of microporous polypropylene membrane(MPPM)with lactose-based polyols.The affinity is based on specific complexation between bo...Affinity membranes are fabricated for boric acid removal by the surface functionalization of microporous polypropylene membrane(MPPM)with lactose-based polyols.The affinity is based on specific complexation between boric acid and saccharide polyols.A photoinduced grafting-chemical reaction sequence was used to prepare these affinity membranes.Poly(2-aminoethyl methacrylate hydrochloride)[poly(AEMA)]was grafted on the surfaces of MPPM by UV-induced graft polymerization.Grafting in the membrane pores was visualized by dying the cross-section of poly(AEMA)-grafted MPPM with fluorescein disodium and imaging with confocal laser scanning microscopy.It is concluded that lactose ligands can be covalently immobilized on the external surface and in the pores by the subsequent coupling of poly(AEMA)with lactobionic acid(LA).Physical and chemical properties of the affinity membranes were characterized by field emission scanning electron microscopy and Fourier Transform Infrared/Attenuated Total Refraction spectroscopy(FT-IR/ATR).3-Aminophenyl boric acid(3-APBA)was removed from aqueous solution by a single piece of lactose-functionalized MPPM in a dynamic filtration system.The results show that the 3-APBA removal reaches an optimal efficiency(39.5%)under the alkaline condition(pH9.1),which can be improved by increasing the immobilization density of LA.Regeneration of these affinity membranes can be easily realized through acid-base washing because the complexation of boric acid and saccharide polyol is reversible.展开更多
Irritable bowel syndrome (IBS) is a lifelong condition with a high prevalence among children and adults. As the diet is a frequent factor that triggers the symptoms, it has been assumed that by avoiding the consumptio...Irritable bowel syndrome (IBS) is a lifelong condition with a high prevalence among children and adults. As the diet is a frequent factor that triggers the symptoms, it has been assumed that by avoiding the consumption of fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP), the symptoms might be improved. Therefore, in the past decade, low FODMAP diet has been intensively investigated in the management of IBS. The capacity of FODMAPs to trigger the symptoms in patients with IBS was related to the stimulation of mechanoreceptors in the small and large intestine. This stimulation appears as a response to a combination of increased luminal water (the osmotic effect) and the release of gases (carbon dioxide and hydrogen) due to the fermentation of oligosaccharides and malabsorption of fructose, lactose and polyols. Numerous studies have been published regarding the efficacy of a low FODMAP diet compared to a traditional diet in releasing the IBS symptoms in adults, but there are only a few studies in the juvenile population. The aim of this review is to analyze the current data on both low FODMAP diet in children with IBS and the effects on their nutritional status and physiological development, given the fact that it is a restrictive diet.展开更多
This study dealt with the electrostrictive responses of polyurethane （PU） actuators with different microphase separation structure, which was a promising candidate for a material used in polymer actuators. In order ...This study dealt with the electrostrictive responses of polyurethane （PU） actuators with different microphase separation structure, which was a promising candidate for a material used in polymer actuators. In order to construct PUs with different higher-order structure, PUs with various types of polyol were synthesized： poly（neopentyl glycol adipate） （PNAD）, poly（tetramethylene glycol） （PTMG）, and poly（dimethyl siloxnae） （PDMS）. Synthesized PU was characterized by Fourier transform-infrared （FT-IR） spectroscopy and gel per- meation chromatography （GPC）. Thermal analysis and mechanical properties of PU films were carried out with differential scanning calorimetry （DSC） and UTM （universal testing machine）, respectively. And PU actuator was formed in a type of monomorph, which was made by carbon black electrodes on the both surfaces of PU film by spin coating method. Actuation behavior was mainly influenced on microphase separation struc- ture and mechanical property of PU. In result, PU actuator with PNAD, polyester urethane, had the largest field-induced displacement.展开更多
As the polyurethane foam(PUF)market,especially in the automotive sector,continues to grow,the environmental impacts of its petrochemical demands and end-of-life waste have motivated the industry to look for more susta...As the polyurethane foam(PUF)market,especially in the automotive sector,continues to grow,the environmental impacts of its petrochemical demands and end-of-life waste have motivated the industry to look for more sustainable solutions.This study explores the preparation of recyclable PUFs using commercially available soy polyols(Cargill's BiOH),aiming to enable improved thermal reprocessability of flexible PUFs via vitrimer chemistry.A series of“soy-PUFs”was produced by partially substituting petrochemical polyether polyols with 25%or 50%soy polyols in a standard reference formulation.Incorporation of soy polyols resulted in an increase in the stiffness of the resulting foams.Employing a modest amount(∼0.5 wt%)of dibutyltin dilaurate(DBTDL)in the formulations facilitated dynamic covalent bond exchanges in the cross-linked network during a mild“foam-to-sheet”reprocessing process(160°C),converting malleable PUFs into densified sheet materials(PUS)with proper compactness and mechanical performance(e.g.,tensile modulus=∼50 MPa).Soy-PUFs demonstrated a modestly enhanced stress relaxation behavior,suggesting adequate reprocessing ability.DMA results demonstrated the phenomenon of forming an“intermediate”region between the hard and soft domains of PUSs after reprocessing.展开更多
PU,or polyurethane,features a repeating urethane group(-NH-COO-)in its molecular structure.Traditionally,PUs are synthesized from isocyanate and polyol compounds derived from fossil resources through polymerization re...PU,or polyurethane,features a repeating urethane group(-NH-COO-)in its molecular structure.Traditionally,PUs are synthesized from isocyanate and polyol compounds derived from fossil resources through polymerization reactions.The depletion of fossil fuels and the increasing climate problems call for the expansion of more renewable sources of chemicals,such as modern biomass.However,the conversion of biomass into chemicals is challenging due to the inherent molecular complexity of its composition.In recent years,advances in green chemistry have led researchers to focus on developing bio-based polyurethanes by sourcing polyols,isocyanates,and chain extender precursors from biological materials.This paper focuses on the preparation of polyols,non-isocyanates and bio-based chain extenders from bio-based materials such as vegetable oils,lignin,sugars,and rosin.The synthetic routes and properties of several bio-based polyurethane materials are analyzed.Additionally,it discusses the current status,future challenges,and potential applications of bio-based polyurethane materials across various fields.展开更多
It is of great significance and challenge to achieve direct conversion of cellulose to specific polyols,e.g.,ethylene glycol and propylene glycol.For such selective conversion,a novel one-pot approach was studied by c...It is of great significance and challenge to achieve direct conversion of cellulose to specific polyols,e.g.,ethylene glycol and propylene glycol.For such selective conversion,a novel one-pot approach was studied by combination of alkaline hydrolysis and hydrogenation on supported Ru catalysts.A wide range of bases including solid bases,e.g.,Ca(OH)2 and La2O3,and phosphate buffers were examined in the cellulose reaction in water,and the cellulose conversions and polyol products depended largely on the basicity or pH values in the aqueous solutions.Ethylene glycol,1,2-propanediol,and especially 1,2,5-pentanetriol were obtained with selectivities of 15%,14% and 22%,respectively,at 38% cellulose conversion at pH 8 in phosphate buffer solution.These preliminary results provide potentials for efficient conversion of cellulose to targeted polyols by using the advantages of bases.展开更多
We report the highly efficient conversion of readily available biomass-derived polyols with amines to valuable furfurylamines orβ-amino alcohols compounds using ruthenium catalysis.The reaction outcome is readily tun...We report the highly efficient conversion of readily available biomass-derived polyols with amines to valuable furfurylamines orβ-amino alcohols compounds using ruthenium catalysis.The reaction outcome is readily tuned by the simple addition of 4Åmolecular sieves(furfurylamines vs.β-amino alcohols)with high chemo-selectivity.The proposed reaction mechanism involves ruthenium-catalyzed hydrogen borrowing for the reduction of the imine intermediate and C–C bond cleavage of polyols via a retro-aldol process.A series of arylamines was suc-cessfully transformed into the desired products with moderate to good yields.展开更多
Iron(Fe)is a micronutrient for living organisms,and maintenance of Fe homeostasis is required for normal physiological functions.In this study,we report the function of a plasma membrane localized transporter(Polyol t...Iron(Fe)is a micronutrient for living organisms,and maintenance of Fe homeostasis is required for normal physiological functions.In this study,we report the function of a plasma membrane localized transporter(Polyol transporter 8,TaPLT8)in wheat,which is regarded as a novel regulator for Fe transport.TaPLT8 is specifically expressed in wheat roots and is induced by environmental Fe.Knockout of TaPLT8 increased Fe accumulation in roots but resulted in decreased Fe levels in shoots and grain.The change was caused by an altered tolerance or increased susceptibility to excessive environmental Fe in the vicinity of wheat roots,and inhibited root growth.Overexpression of TaPLT8A improved Fe transport from roots to shoots and grains,and increased grain Fe levels by up to 14.46%.Compared to wild type(WT)plants,the levels of Citrate and Fe levels in xylem sap were significantly decreased in taplt8 mutants but significantly increased in TaPLT8 OE lines.Transcriptome analysis of taplt8 mutants indicated that TaPLT8 affected citrate levels by influencing glycolysis and the citrate cycle pathway in roots,thus impacting Fe translocation.The findings demonstrated that TaPLT8 mediates Fe distribution in wheat roots and shoots,contributing to greater understanding of the contribution of TaPLT8 to Fe accumulation in grains.展开更多
In the organic Rankine cycle,the refrigerant inevitably interacts with the lubricating oil.This study investigates the interaction mechanism between the fourth-generation refrigerant R1336mzz(Z)and the polyol ester(PO...In the organic Rankine cycle,the refrigerant inevitably interacts with the lubricating oil.This study investigates the interaction mechanism between the fourth-generation refrigerant R1336mzz(Z)and the polyol ester(POE)which is a representative component of the lubricating oil,using molecular dynamics simulations.The research focuses on pentaerythritol ester(PEC)with medium to long chain lengths,specifically PEC9.Relevant parameters such as solubility parameters,diffusion coefficients,binding energies,and radial distribution functions were calculated to elucidate the interaction dynamics.The variation in solubility parameters suggests that the miscibility of PEC9 and R1336mzz(Z)diminishes as the number of PEC9 chains increases.Additionally,the compatibility between these two components deteriorates with rising temperature,which is accompanied by a reduction in their binding energy.The simulation results presented in this study offer theoretical insights into the behavior of refrigerant R1336mzz(Z)upon contact with lubricating oil during actual operation,as well as implications for the operational efficiency of the equipment.展开更多
Corrigendum:Epalrestat protects against diabetic peripheral neuropathy by alleviating oxidative stress and inhibiting polyol pathway https://doi.org/10.4103/NRR.NRR-D-25-00562 In the article titled“Epalrestat protect...Corrigendum:Epalrestat protects against diabetic peripheral neuropathy by alleviating oxidative stress and inhibiting polyol pathway https://doi.org/10.4103/NRR.NRR-D-25-00562 In the article titled“Epalrestat protects against diabetic peripheral neuropathy by alleviating oxidative stress and inhibiting polyol pathway,”published on pages 345-351 in Issue 2,Volume 11 of Neural Regeneration Research(Li et al.,2016),the Western blot bands in Figure 2A are incorrect.展开更多
基金financial support from the Latvian Council of Science,Project No.lzp-2021/1-0207.
文摘The isolated hydrophilic black alder(Alnus glutinosa)bark extractives were characterized in terms of component and functional composition and converted at 150℃-170℃ into liquid green polyols using solvent-free and lowtoxic base-catalyzed modification with propylene carbonate(PC).FTIR spectroscopy,HP-LC,GC,GPC,and wet chemistry methods were used to characterize the starting constituents,intermediate and final products of the reaction and to monitor the different pathways of PC conversion.The reaction of extractives as well as the model compounds,including catechol,xylose,PEG 400,and benzoic acid,with PC indicated the ability of OH groups of different origins present in the extractives to condense with equivalent amounts of PC.The polyols obtained consist of a copolymer fraction with one oxypropyl unit grafted per OH functionality of extractive components on average and oligo oxypropyl diols with a small number of carbonate linkages in the chain,obtained as a result of remaining PC homopolymerization.The domination of the oxypropylation mechanism vs.transcarbonation for PC ring opening was observed for both copolymerization and homopolymerization processes,making the process of oxypropylation with PC similar to that of conventional oxypropylation.At optimal reaction conditions,including a PC/OH ratio of 3.0 and a 24-h duration at 150°C,uniform polyols with low viscosity of~900 mPa·s^(-1),a biomass content of~27%,and an OHV of~500 mg KOH·g^(-1) were obtained.Increasing the temperature of modification allows shortening the process but drastically increases the polyol viscosity.At fixed temperature values,increasing the PC/OH ratio not only decreases the biomass content but also strongly prolongs the processing.The significantly increased duration of the process using PC as an alternative oxyalkylation agent compared to that of oxyalkylation with propylene oxide is a reasonable trade-off for using a safer and more environmentally friendly technology.
基金V. ACKNOWLEDGMENTS This work was supported by the National High-Tech Research and Development 863 Program of China （No.2012AA101806）, the National Natural Science Foundation of China （No.21306195 and No.51276183）, and the National Key Basic Research Program 973 Project from Ministry of Science and Technology of China （No.2012CB215304）.
文摘The activities of nickel supported on MCM-41 catalysts, prepared by co-impregnation with polyols （ethylene glycol, glycerol, xylitol, sorbitol and glucose）, were investigated by hydrogenation of naphthalene. Compared with the conventional wetness impregnation, addition of moderate polyols into the metal nitrate support surface, resulting in formation of persion of the active phase and significant aqueous solution could enhance interaction with very small NiO particle size （〈5 nm）, high discatalytic activity. Particle size of Ni^0 decreased from 36.1 nm to below 5 nm; meanwhile the complete hydrogenation of naphthalene was dependent on the Ni^0 particle size. The hydrogenation activities of the catalysts prepared by co-impregnation with polyols were very high with 100% conversion even at iow temperature of 55 ℃.
文摘In the present study we report on changes in irritable bowel syndrome-severity scoring system (IBS-SSS) and irritable bowel syndrome-quality of life (IBS-QoL) in 19 IBS patients, aged 18 to 74 years (F/M: 14/5), during 12 wk registering their symptoms on the web-application (www.ibs.constant-care.dk). During a control period of the first 6-wk patients were asked to register their IBS-SSS and IBS-QoL on the web-application weekly without receiving any intervention. Thereafter, low fermentable oligo-, di-, mono-saccharides and polyols (FODMAP) diet (LFD) was introduced for the next 6 wk while continuing the registration. Though a small sample size a significant improvement in disease activity (IBS-SSS) was observed during both the control period, median: 278 (range: 122-377), P = 0.02, and subsequently during the LFD period, median: 151 (range: 29-334), P < 0.01. The IBS-QoL solely changed significantly during the LFD period, median: 67 (37-120), P < 0.01. The significant reduction in disease activity during the control period shows a positive effect of the web-application on IBS symptoms when presented as a “traffic light”. However adding the diet reduced IBS-SSS to < 150, inactive to mild symptoms. In the future results from larger scale trials are awaited.
基金Supported by the National Natural Science Foundation of China(31670577,31670578,31570563)
文摘Three kinds of tung oil-based structural flame retardants polyols(TOFPs) were prepared by new methods in this paper. First, tung oil was used to produce monoglyceride and diglyceride by transesterification with glycerol by sodium methoxide. The products after transesterification were epoxidized by peracetic acid which was in-situ generated from acetic acid and hydrogen peroxide in the presence of sulfuric acid catalyst. And then, TOFPs were prepared from epoxidized alcoholysis tung oil(EGTO) with 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide(DOPO), diethyl phosphate(DEP) and diethanolamine(DEA) by ring-opening reactions, respectively. GPC was used to evaluate the conversion rate, at optimum reaction conditions, selectivity for monoglyceride in transesterification. The influence of different parameters such as temperature, mole ratio or mass ratio on the conversion rate of transesterification and epoxidation were investigated. The molecular structures of TOFPs were characterized by FTIR and ~1HNMR. Finally, tung oil-based polyurethane foams(TOPUFs) were prepared by a one-shot process using TOFPs with polyisocyanate. The LOI values of TOPUFs whose content of DOPO-EGTO,DEP-EGTO and DEA-EGTO were 100 wt% can reach to 26.2%, 25.1%, and 24.4%, respectively.
基金supported by scientific research project of Zhejiang Provincial Education Department(Grant No.Y20112088,China)Science and technology project of Zhejiang Province(Grant No.2011R09028-10,China)
文摘A series of self-reducing bifunctional Ni-W/SBA-15 catalysts were synthesized using biomass-based carbon source as the reducing agent without conventional further reduction step. The self-reducing catalysts were performed on the hydrogenolysis of cellulose to low carbon polyols. The effects of calcination temperature and metallic loading contents for cellulose hydrogenolysis reaction were investigated detailedly.The optimal calcination temperature was found to be 673 K by TG analysis. The active metal nanoparticles with a better dispersion were observed using SEM and element mapping technology. The yield of low carbon polyols using the catalyst with the receipt of 10%Ni-15%W/SBA-15-673 K can reach as high as68.14%, of which the ethylene glycol(EG) accounts for 61.04%.
文摘Recently, hyperbranched polymers(HBPs), which differ significantly in structure and properties from linear, cross-linked and branched analogs, have become increasingly important. HBP have a spatial unloaded core and a shell of branched monomer units(dendrons), in which functional groups are predominantly located in the surface layer. The size of macromolecules ranges from 2 nm to 100 nm. Currently, there are a fairly large number of publications in the literature devoted to the modification of hyperbranched polyester polyols with various functional groups and the assessment of the potential for their use. However, there are no review articles on this topic in recent years. In this regard, it is relevant to generalize the latest achievements in the field of synthesis, properties and application of hyperbranched polyester polyols with terminal oxygen, nitrogen, silicon, sulfur and organophosphorus fragments. The advantage of hyperbranched polyester polyols of the Boltorn H series is their industrial availability, biodegradability, nanoscale, non-toxicity and high solubility in various polar solvents due to short monomer units, as well as the presence of reactive terminal hydroxyl groups. Functionalization of hyperbranched polyester polyols at hydroxyl groups is mainly carried out by addition of acid anhydrides, iso(thio)cyanates, alkenes, lactides, lactones, lactams, epoxy compounds or reactions with halogenated compounds(alkyl halides, acid chlorides). In some cases, for the functionalization of polyester polyols special linkers are used, such as acid chlorides of unsaturated or dicarboxylic acids, diisocyanates, etc., which provide covalent bonding of the hyperbranched polymer with the target functional group. The obtained derivatives of hyperbranched polyesters are widely used in such areas as biomedicine, pharmacy, paints and varnishes, they are also used as catalysts, membranes, multifunctional coatings, plasticizers and polymer stabilizers.
基金financial support from Natural Science Foundation of Guangdong Province(2018A030313423)Key Research and Development Program of Guangdong Province(2020B090919005)Pearl River Science and Technology New Star Project(201806010039).
文摘Phosphate material LiMnPO4 is popular for its high energy density(697 W·h·kg^(-1))and safety.When LiMnPO_(4) crystal grows,the potential barrier along b and c axis is strong,which makes the crystal grow along b axis to form a one-dimensional chain structure.However,the main migration channel of lithium ions in olivine structure is plane(010).By shortening the growth in the direction of b axis and enhancing the diffusion along the directions of a and c,two-dimensional nanosheets that are more conducive to the migration of lithium ions are formed.The dosage of polyols is the key factor guiding the dispersion of the crystals to the(010)plane.X-ray diffraction(XRD),Scanning electron microscopy(SEM),transmission electron microscopy(TEM)and other means are used to characterize the samples.After experiments,we found that when the ratio of polyol/water was 2:1,the morphology of the synthesized sample was 20–30 nm thick nanosheets,which had the best electrochemical performance.At 0.1C,the discharge specific capacity reaches 148.9 mA·h·g^(-1),still reaches 144.3 mA·h·g^(-1) at the 50th cycle.and there is still 112.5 mA·h·g^(-1) under high rate(5C).This is thanks to the good dispersion of the material in the direction of the crystal plane(010).This can solve the problem of low conductivity and ionic mobility of phosphate materials.
基金supported by the National Key R&D Program of China (No.2018YFB1501404)
文摘This work proved that biomass-based polyols (sorbitol, xylitol, erythritol, glycerol and ethanediol) were able to be converted into high-value chemical (p-xylene) by catalytic cracking of polyols, alkylation of aromatics, and the isomerization of xylenes over the SiO2-modified zeolites. Compared to the conventional HZSM-5 zeolite, the SiO2-containing zeolites considerably increased the selectivity and yield of p-xylene due to the reduction of external surface acidity and the narrowing of pore entrance. The influences of the methanol additive, reaction temperature, and types of polyols on the selectivity and yield of p-xylene were investigated in detail. Catalytic cracking of polyols with methanol significantly enhanced the production of p-xylene by the alkylation of toluene with methanol. The highest p-xylene yield of 10.9 C-mol% with a p-xylene/xylenes ratio of 91.1% was obtained over the 15wt%SiO2/HZSM-5 catalyst. The reaction pathway for the formation of p-xylene was addressed according to the study of the key reactions and the characterization of catalysts.
基金supported by the National Natural Science Foundation of China (nos. 21306191 21376239+1 种基金 21690080 21690081)
文摘Catalytic conversion of glucose, the most abundant carbohydrate, to chemicals of petroleum origin has great desirability in terms of sustainability and industrial implementation. In this work, we attempted to exploit the vanadium-based catalysts with high retro-aldol condensation(RAC) activity for the synthesis of small polyols from glucose. Vanadium species incorporated or anchored beta zeolites were found to work effectively in synergy with 1 Ru/AC to produce hydroxyacetone(HA) as the major product(34%)in a semi-continuously stirred tank reactor under 5% glucose concentration. Catalyst characterization by UV-vis and Raman spectral analysis revealed vanadium species mainly stayed in the incorporated form(tetrahedral) at 0.5% of loading and in the supported form(octahedral) at higher loadings up to 8%. Pyridine infrared spectra and temperature programmed desorption of NH3 revealed weak Lewis acid sites in dominance. Vanadium species in the catalysts displayed multiple catalytic roles(isomerization and RAC reaction, and synergism with the hydrogenation catalyst) in the synthesis of HA from glucose. Structureactivity correlation pointed out that the catalytic activity of vanadium species is not dependent on it coordination status, nevertheless, the adjacent vanadium atoms could possibly improve the isomerization rate over the RAC rate in favor of high yield of HA. The catalyst system is recyclable to at least five times without any considerable loss in its activity and structural integrity. The results presented here provide a promising route for the sustainable production of HA and polyols from carbohydrates by using a highly selective vanadium catalyst.
文摘Advanced wound dressings are replaced traditional dressings in order to provide appropriate environment for healing and also to promote cell migration[1].The key characteristics of wound dressings are non-toxic,highly absorbed,air permeable,biocompatible and have good mechanical properties[2].Due to providing moist environment and also protecting maceration at the wound edge area,foam dressings are used in various clinical applications[3].They are mostly prepared from polyurethane between polyols and isocyanate polymerization.
基金Supported by the National Natural Science Foundation of China(50933006)the National Basic Research Program of China(2009CB623401)
文摘Affinity membranes are fabricated for boric acid removal by the surface functionalization of microporous polypropylene membrane(MPPM)with lactose-based polyols.The affinity is based on specific complexation between boric acid and saccharide polyols.A photoinduced grafting-chemical reaction sequence was used to prepare these affinity membranes.Poly(2-aminoethyl methacrylate hydrochloride)[poly(AEMA)]was grafted on the surfaces of MPPM by UV-induced graft polymerization.Grafting in the membrane pores was visualized by dying the cross-section of poly(AEMA)-grafted MPPM with fluorescein disodium and imaging with confocal laser scanning microscopy.It is concluded that lactose ligands can be covalently immobilized on the external surface and in the pores by the subsequent coupling of poly(AEMA)with lactobionic acid(LA).Physical and chemical properties of the affinity membranes were characterized by field emission scanning electron microscopy and Fourier Transform Infrared/Attenuated Total Refraction spectroscopy(FT-IR/ATR).3-Aminophenyl boric acid(3-APBA)was removed from aqueous solution by a single piece of lactose-functionalized MPPM in a dynamic filtration system.The results show that the 3-APBA removal reaches an optimal efficiency(39.5%)under the alkaline condition(pH9.1),which can be improved by increasing the immobilization density of LA.Regeneration of these affinity membranes can be easily realized through acid-base washing because the complexation of boric acid and saccharide polyol is reversible.
文摘Irritable bowel syndrome (IBS) is a lifelong condition with a high prevalence among children and adults. As the diet is a frequent factor that triggers the symptoms, it has been assumed that by avoiding the consumption of fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP), the symptoms might be improved. Therefore, in the past decade, low FODMAP diet has been intensively investigated in the management of IBS. The capacity of FODMAPs to trigger the symptoms in patients with IBS was related to the stimulation of mechanoreceptors in the small and large intestine. This stimulation appears as a response to a combination of increased luminal water (the osmotic effect) and the release of gases (carbon dioxide and hydrogen) due to the fermentation of oligosaccharides and malabsorption of fructose, lactose and polyols. Numerous studies have been published regarding the efficacy of a low FODMAP diet compared to a traditional diet in releasing the IBS symptoms in adults, but there are only a few studies in the juvenile population. The aim of this review is to analyze the current data on both low FODMAP diet in children with IBS and the effects on their nutritional status and physiological development, given the fact that it is a restrictive diet.
基金supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education,Science and Technology (No.2009-0065385) and Advanced Ship Engineering Research Center (ASERC)
文摘This study dealt with the electrostrictive responses of polyurethane （PU） actuators with different microphase separation structure, which was a promising candidate for a material used in polymer actuators. In order to construct PUs with different higher-order structure, PUs with various types of polyol were synthesized： poly（neopentyl glycol adipate） （PNAD）, poly（tetramethylene glycol） （PTMG）, and poly（dimethyl siloxnae） （PDMS）. Synthesized PU was characterized by Fourier transform-infrared （FT-IR） spectroscopy and gel per- meation chromatography （GPC）. Thermal analysis and mechanical properties of PU films were carried out with differential scanning calorimetry （DSC） and UTM （universal testing machine）, respectively. And PU actuator was formed in a type of monomorph, which was made by carbon black electrodes on the both surfaces of PU film by spin coating method. Actuation behavior was mainly influenced on microphase separation struc- ture and mechanical property of PU. In result, PU actuator with PNAD, polyester urethane, had the largest field-induced displacement.
基金the financial support from the United Soybean Board,Project No.2333-102-0201 and 2422-106-010.
文摘As the polyurethane foam(PUF)market,especially in the automotive sector,continues to grow,the environmental impacts of its petrochemical demands and end-of-life waste have motivated the industry to look for more sustainable solutions.This study explores the preparation of recyclable PUFs using commercially available soy polyols(Cargill's BiOH),aiming to enable improved thermal reprocessability of flexible PUFs via vitrimer chemistry.A series of“soy-PUFs”was produced by partially substituting petrochemical polyether polyols with 25%or 50%soy polyols in a standard reference formulation.Incorporation of soy polyols resulted in an increase in the stiffness of the resulting foams.Employing a modest amount(∼0.5 wt%)of dibutyltin dilaurate(DBTDL)in the formulations facilitated dynamic covalent bond exchanges in the cross-linked network during a mild“foam-to-sheet”reprocessing process(160°C),converting malleable PUFs into densified sheet materials(PUS)with proper compactness and mechanical performance(e.g.,tensile modulus=∼50 MPa).Soy-PUFs demonstrated a modestly enhanced stress relaxation behavior,suggesting adequate reprocessing ability.DMA results demonstrated the phenomenon of forming an“intermediate”region between the hard and soft domains of PUSs after reprocessing.
基金supported by the China Postdoctoral Science Foundation(No.200902090)Tianjin Enterprise Science and Technology Commissioner Project(No.21YDTPJC00570).
文摘PU,or polyurethane,features a repeating urethane group(-NH-COO-)in its molecular structure.Traditionally,PUs are synthesized from isocyanate and polyol compounds derived from fossil resources through polymerization reactions.The depletion of fossil fuels and the increasing climate problems call for the expansion of more renewable sources of chemicals,such as modern biomass.However,the conversion of biomass into chemicals is challenging due to the inherent molecular complexity of its composition.In recent years,advances in green chemistry have led researchers to focus on developing bio-based polyurethanes by sourcing polyols,isocyanates,and chain extender precursors from biological materials.This paper focuses on the preparation of polyols,non-isocyanates and bio-based chain extenders from bio-based materials such as vegetable oils,lignin,sugars,and rosin.The synthetic routes and properties of several bio-based polyurethane materials are analyzed.Additionally,it discusses the current status,future challenges,and potential applications of bio-based polyurethane materials across various fields.
基金supported by the National Natural Science Foundation of China (20733009, 20825310 & 20973011)the National Basic Research Program of China (2006CB806100)
文摘It is of great significance and challenge to achieve direct conversion of cellulose to specific polyols,e.g.,ethylene glycol and propylene glycol.For such selective conversion,a novel one-pot approach was studied by combination of alkaline hydrolysis and hydrogenation on supported Ru catalysts.A wide range of bases including solid bases,e.g.,Ca(OH)2 and La2O3,and phosphate buffers were examined in the cellulose reaction in water,and the cellulose conversions and polyol products depended largely on the basicity or pH values in the aqueous solutions.Ethylene glycol,1,2-propanediol,and especially 1,2,5-pentanetriol were obtained with selectivities of 15%,14% and 22%,respectively,at 38% cellulose conversion at pH 8 in phosphate buffer solution.These preliminary results provide potentials for efficient conversion of cellulose to targeted polyols by using the advantages of bases.
基金support from the National Natural Science Foundation of China(NSFC,Nos.21633013,22022204).
文摘We report the highly efficient conversion of readily available biomass-derived polyols with amines to valuable furfurylamines orβ-amino alcohols compounds using ruthenium catalysis.The reaction outcome is readily tuned by the simple addition of 4Åmolecular sieves(furfurylamines vs.β-amino alcohols)with high chemo-selectivity.The proposed reaction mechanism involves ruthenium-catalyzed hydrogen borrowing for the reduction of the imine intermediate and C–C bond cleavage of polyols via a retro-aldol process.A series of arylamines was suc-cessfully transformed into the desired products with moderate to good yields.
基金supported by the National Key Research and Development Program of China(2023YFF1001500)Young Scientists Fund of the National Natural Science Foundation of China(32401811)+3 种基金Key Program of Sichuan Natural Science Foundation(2022NSFSC0015)local financial funds of the National Agricultural Science and Technology Center,Chengdu(NASC2024KR01)research start up fund of Chengdu Agricultural College(25BS02),Significant Science and Technology Project of China National Tobacco Corporation(110202101060(XJ-09))Natural Science Foundation of Sichuan Province(2024NSFSC1204).
文摘Iron(Fe)is a micronutrient for living organisms,and maintenance of Fe homeostasis is required for normal physiological functions.In this study,we report the function of a plasma membrane localized transporter(Polyol transporter 8,TaPLT8)in wheat,which is regarded as a novel regulator for Fe transport.TaPLT8 is specifically expressed in wheat roots and is induced by environmental Fe.Knockout of TaPLT8 increased Fe accumulation in roots but resulted in decreased Fe levels in shoots and grain.The change was caused by an altered tolerance or increased susceptibility to excessive environmental Fe in the vicinity of wheat roots,and inhibited root growth.Overexpression of TaPLT8A improved Fe transport from roots to shoots and grains,and increased grain Fe levels by up to 14.46%.Compared to wild type(WT)plants,the levels of Citrate and Fe levels in xylem sap were significantly decreased in taplt8 mutants but significantly increased in TaPLT8 OE lines.Transcriptome analysis of taplt8 mutants indicated that TaPLT8 affected citrate levels by influencing glycolysis and the citrate cycle pathway in roots,thus impacting Fe translocation.The findings demonstrated that TaPLT8 mediates Fe distribution in wheat roots and shoots,contributing to greater understanding of the contribution of TaPLT8 to Fe accumulation in grains.
基金supported by Hainan Provincial Natural Science Foundation of China(No.422CXTD509).
文摘In the organic Rankine cycle,the refrigerant inevitably interacts with the lubricating oil.This study investigates the interaction mechanism between the fourth-generation refrigerant R1336mzz(Z)and the polyol ester(POE)which is a representative component of the lubricating oil,using molecular dynamics simulations.The research focuses on pentaerythritol ester(PEC)with medium to long chain lengths,specifically PEC9.Relevant parameters such as solubility parameters,diffusion coefficients,binding energies,and radial distribution functions were calculated to elucidate the interaction dynamics.The variation in solubility parameters suggests that the miscibility of PEC9 and R1336mzz(Z)diminishes as the number of PEC9 chains increases.Additionally,the compatibility between these two components deteriorates with rising temperature,which is accompanied by a reduction in their binding energy.The simulation results presented in this study offer theoretical insights into the behavior of refrigerant R1336mzz(Z)upon contact with lubricating oil during actual operation,as well as implications for the operational efficiency of the equipment.
文摘Corrigendum:Epalrestat protects against diabetic peripheral neuropathy by alleviating oxidative stress and inhibiting polyol pathway https://doi.org/10.4103/NRR.NRR-D-25-00562 In the article titled“Epalrestat protects against diabetic peripheral neuropathy by alleviating oxidative stress and inhibiting polyol pathway,”published on pages 345-351 in Issue 2,Volume 11 of Neural Regeneration Research(Li et al.,2016),the Western blot bands in Figure 2A are incorrect.
