Traditional biodiesel production primarily uses methanol as the acyl acceptor,but its toxicity to lipase increases process complexity and operational difficulty elevate manufacturing costs.This study aimed to explore ...Traditional biodiesel production primarily uses methanol as the acyl acceptor,but its toxicity to lipase increases process complexity and operational difficulty elevate manufacturing costs.This study aimed to explore a new method for enzymatic synthesis of biodiesel with methyl methacrylate(MMA)as acyl acceptor.Meanwhile,a 1,3-position specific lipase Lipozyme RM IM was applied as biocatalyst,which enables simultaneous production of biodiesel(FAMEs)and methacrylate fatty acid glycerides(MFAGs)via specific sn-1,3 transesterification of MMA with triglyceride.Under the optimal reaction conditions:temperature of 50℃,molar ratio of 4:1 for MMA to triglyceride,enzyme dosage of 7.5%(mass),and an extra water addition of 0.5%(mass);triglyceride conversion rate of 97%,and FAMEs yield of 65%could be obtained.Simultaneously,the multistage short-path distillation and column chromatographic method were combined used for the separation of the mixed products.Finally,the purity of FAME,MFADG,DMFAG,and MMFAG were 98%,97.8%,95.3%,and 81.78%,respectively.In this new approach,MMA demonstrates lower toxicity to lipases,allowing for straightfo rward addition of all the substrates without complex addition process,and enhancing operational feasibility.Meanwhile,the by-products of MFAGs could be applied as monomers in varnishes and protective coatings,which increased the value of the products.Thus,this investigation providing an alternative way to produce biodiesel,and providing a new pathway for the sustainable development of biodiesel.展开更多
Polybutylacrylate (PBA)/poly(methyl methacrylate) (PMMA) core-shell elastic particles (CSEP), whose rubbery core diameter ranged from 0.08 μm to 1.38μm, were synthesized by using conventional emulsion polymerization...Polybutylacrylate (PBA)/poly(methyl methacrylate) (PMMA) core-shell elastic particles (CSEP), whose rubbery core diameter ranged from 0.08 μm to 1.38μm, were synthesized by using conventional emulsion polymerization, multi-step emulsion polymerization, and soapless polymerization. Allyl methacylate (ALMA) and ethylene glycol dimethacrylate (EGDMA) were selected as crosslinking reagents for core polymerization. Methacrylic acid (MAA) was used as functional co-monomer with methyl methacrylate as shell component. The content of vinyl groups in PBA rubbery core increased with the amount of crosslinking reagents. The core-shell ratio affected great on the morphology of the complex particles. Furthermore, the amounts of carboxyl on the surface of core-shell particles, copolymerized with acrylic acid, were determined by potentiometric titration. Results showed that methylacrylic acid was distributed mostly on the surface of particles.展开更多
Two new chiral ionic liquids, 1 -((-)-menthoxycarbonylmethylene)-3-methylimidazolium hexafluorophosphateand 1-((-)-menthoxycarbonylmethylene)-3-hexadecylimidazolium hexafluorophosphate, were designed an d prepared. Th...Two new chiral ionic liquids, 1 -((-)-menthoxycarbonylmethylene)-3-methylimidazolium hexafluorophosphateand 1-((-)-menthoxycarbonylmethylene)-3-hexadecylimidazolium hexafluorophosphate, were designed an d prepared. Theirchemical structures were characterized by ~1H-NMR. Reverse atom transfer radical polymerization of methyl methacrylate(MMA) in these two ionic liquids was carried out using AIBN/CuCl_2/bipy as the initiating system. The resultant well-definedpolymethyl methacrylate (PMMA) was employed as a macroinitiator to induce the atom transfer radical polymerization ofmenthyl methacrylate (MnMA) in chlorobenzene, which yielded a PMMA-b-PMnMA diblock copolymer with narrow polydispersity.展开更多
Poly methyl methacrylate(PMMA)bone cement is used in augmenting and stabilizing fractured vertebral bodies through percutaneous vertebroplasty(PVP)and percutaneous kyphoplasty(PKP).However,applications of PMMA bone ce...Poly methyl methacrylate(PMMA)bone cement is used in augmenting and stabilizing fractured vertebral bodies through percutaneous vertebroplasty(PVP)and percutaneous kyphoplasty(PKP).However,applications of PMMA bone cement are limited by the high elasticity modulus of PMMA,its low biodegradability,and its limited ability to regenerate bone.To improve PMMA bio activity and biodegradability and to modify its elasticity modulus,we mixed PMMA bone cement with oxidized hyaluronic acid and carboxymethyl chitosan in situ cross-linking hydrogel loaded with bone morphogenetic protein-2(BMP-2)to achieve novel hybrid cement.These fabric ated PMMA-hydrogel hybrid cements exhibited lower setting temperatures,a lower elasticity modulus,and better biodegradability and biocompatibility than that of pure PMMA cement,while retaining acceptable setting times,mechanical strength,and inj ectability.In addition,we detected release of BMP-2 from the PMMA-hydrogel hybrid cements,significantly enhancing in vitro osteogenesis of bone marrow mesenchymal stem cells by up-regulating the gene expression of Runx2,Coll,and OPN.Use of PMMA-hydrogel hybrid cements loaded with BMP-2 on rabbit femoral condyle bone-defect models revealed their biodegradability and enhanced bone formation.Our study demonstrated the favorable mechanical properties,biocompatibility,and biodegradability of fabricated PMMA-hydrogel hybrid cements loaded with BMP-2,as well as their ability to improve osteogenesis,making them a promising material for use in PKP and PVP.展开更多
Objective To evaluate the genotoxic and nongenotoxic effects of short-term exposure to glycidyl mathacrylate (GMA) on human lung fibroblast cells (2BS cells) in vitro. Methods DNA strand breakage was determined by sin...Objective To evaluate the genotoxic and nongenotoxic effects of short-term exposure to glycidyl mathacrylate (GMA) on human lung fibroblast cells (2BS cells) in vitro. Methods DNA strand breakage was determined by single cell gel electrophoresis, and DNA ladder formation assay and flow cytometric analysis were carried out to detect apoptic responses of cells to GMA exposure. The HPRT gene mutation assay was used to evaluate the mutagenicity, and the effect of GMA on gap junctional intercellular communication (GJIC) in the exposed cells was examined with the scrape loading/dye transfer technique. The ability of GMA to transform 2BS cells was also tested by an in vitro cell transformation assay. Results Exposure to GMA resulted in a dose-dependent increase in DNA strand breaks but not apoptic responses. GMA was also shown to significantly induce HPRT gene mutations and morphological transformation in 2BS cells in vitro. In contrast, GMA produced a concentration-dependent inhibition of GJIC. Conclusions GMA elicits both genotoxic and nongenotoxic effects on 2BS cells in vitro. The induction of DNA damage and gene mutations and inhibition of GJIC by GMA may casually contribute to GMA-induced cell transformation.展开更多
Poly （ethyleneglycol monomethylether） methacrylate （PEGMM）was synthesized by means of the reaction of methacrylyl chloride with sodium monomethylpolyethyleneglycoxide and was characterized by FTIR,;H-NMR,and ultra...Poly （ethyleneglycol monomethylether） methacrylate （PEGMM）was synthesized by means of the reaction of methacrylyl chloride with sodium monomethylpolyethyleneglycoxide and was characterized by FTIR,;H-NMR,and ultraviolet spectrometries. A series of poly （vinyl alcohol）-graft-PEGMM （PVA-g-PEGMM ）and methyl methacrylate-PEGMM copolymer （PMMA-PEGMM） were prepared and tested for antithrombogenicity in vitro. The results indicate that the antithrombogenicity of the copolymers basically increases with the increasing of the DP of polyoxyethylene （POE） chain and tends to a plateau after the DP around 114,i.e. the long chain structure of POE is favourable to the antithrombogenicityof its copolymers ;moreover, the extent of the improvement ofantithrombogenicity also relates to the PEGMM content of the copolymers and the kind of the matrix that the POE chains are located on. These results are consistent with the anticipation of the hypothesis of maintaining proteins normal conformations for blood compatible bioraaterials.展开更多
Synthesis and characterization of the copolymers （PAG） of α-methyl styrene （AMS） and glycidyl methacrylate （GMA） are presented. The copolymers of PAG were characterized by gel permeation chromatography （GPC）,...Synthesis and characterization of the copolymers （PAG） of α-methyl styrene （AMS） and glycidyl methacrylate （GMA） are presented. The copolymers of PAG were characterized by gel permeation chromatography （GPC）, Fourier transform infrared spectroscopy （FTIR）, nuclear magnetic resonance （^1H-NMR） and thermogravimetery （TG）. Based on the copolymer compositions determined by ^1H-NMR, the reactivity ratios of AMS and GMA were found to be 0.105 ± 0.012 and 0.883 ± 0.046 respectively by Kelen-Tudos method. TG revealed that thermal stability of the copolymers decreased with increasing the AMS content in the copolymers, which indicated that the degradation was mainly caused by the chain scission of AMS-containing structures. Under heating, the copolymers depolymerize at their weak bonds and form chain radicals, which could further initiate other chemical reactions.展开更多
In this study, a UV-curable polysiloxane methacrylate （PSMA） was synthesized by a one-step method. The reaction was catalyzed by chloroplatinic acid between polymethylhydrosiloxane （PMHS） and hydroxyethyl methacry...In this study, a UV-curable polysiloxane methacrylate （PSMA） was synthesized by a one-step method. The reaction was catalyzed by chloroplatinic acid between polymethylhydrosiloxane （PMHS） and hydroxyethyl methacrylate （HEMA）, as proved by FTIR and ^1H-NMR. The preliminary results indicate that the obtained UV-cured PSMA film has very good thermal stability, excellent transparency and satisfactory tensile strength. Our work provides a simple but efficient way to prepare UV-curable PSMA, which may find potential applications in UV-curing optical fiber, metal and glass coating and other fields.展开更多
A novel nanomagnetic organogel was synthesized by in situ emulsion polymerization-crosslinking method using dodecyl methacrylate(DDMA) and styrene(St) as monomers, divinylbenzene(DVB) as a crosslinking agent, azobisis...A novel nanomagnetic organogel was synthesized by in situ emulsion polymerization-crosslinking method using dodecyl methacrylate(DDMA) and styrene(St) as monomers, divinylbenzene(DVB) as a crosslinking agent, azobisisobutyronitrile(AIBN) as an initiator, and Fe_3O_4 as a nanomagnetic particle. Modification of the network was carried out by inclusion of the multi-walled carbon nanotubes(MWCNT) into the organogel matrix. The structure of the nanocomposite was characterized using FTIR spectroscopy, SEM,TEM, TGA/DTG, VSM, and BET analysis. The effects of various parameters such as the amount of crosslinker, initiator, Fe_3O_4, and reaction time as well as monomer ratio on the oil absorption of the organogel were studied. The synthesized organogel can absorb about35.5, 22.1, 29.86, 14.58, 17.6, 15.3, and 13.7 g·g^(-1) of CHCl_3, toluene, CH_2Cl_2, hexane, crude oil, gasoline, and diesel oil, under the optimized polymerization conditions, respectively. The nanocomposite organogels can be easily separated by a magnetic field after absorption of organic solvents.展开更多
Preparing polymeric coatings with well corrosion resistance and high thermal conductivity(TC)to prolong operational life and ensure service reliability of heat conductive metallic materials has long been a substantive...Preparing polymeric coatings with well corrosion resistance and high thermal conductivity(TC)to prolong operational life and ensure service reliability of heat conductive metallic materials has long been a substantive and urgent need while a difficult task.Here we report a multifunctional epoxy composite coating(F-CB/CEP)by synthesizing cerium methacrylate and ingeniously using it as a novel curing agent with corrosion inhibit for epoxy resin and modifier for boron nitride through"cation-π"interaction.The prepared F-CB/CEP coating presents a high TC of 4.29 W m^(−1)K^(−1),which is much higher than other reported anti-corrosion polymer coatings and thereby endowing metal materials coated by this coating with outstanding thermal management performance compared with those coated by pure epoxy coating.Meanwhile,the low-frequency impedance remains at 5.1×10^(11)Ωcm^(2)even after 181 days of immersion in 3.5 wt%NaCl solution.Besides,the coating also exhibits well hydrophobicity,self-cleaning properties,temperature resistance and adhesion.This work provides valuable insights for the preparation of high-performance composite coatings with potential to be used as advanced multifunctional thermal management materials,especially for heat conduction metals protection.展开更多
2-Acryloxyacetophenone （AAP） was prepared and subjected to suspension polymerization with methyl methacrylate （MMA） using azobisisobutyronitrile （AIBN） as free radical initiator. The differently sulfonated AAP-M...2-Acryloxyacetophenone （AAP） was prepared and subjected to suspension polymerization with methyl methacrylate （MMA） using azobisisobutyronitrile （AIBN） as free radical initiator. The differently sulfonated AAP-MMA cross-linked copolymer cationic exchange resins were prepared by sulfonation with concentrated sulphuric acid at 70 ~C. Several characteristics of the prepared resins were evaluated, i.e. FTIR, the ion-exchange capacity （IEC）, thermo gravimetric analysis （TGA）, particle size distribution and microscopic morphology. The resin characteristics were altered with degree of sulfonation, providing that differently sulfonated resins could be prepared. The behavior of atenolol （ATL） loading and in vitro release in the USP stimulated gastric and intestinal fluids of the obtained resins were evaluated. The drug loaded in the resin increased with increasing degree of sulfonation and hence the drug binding site in resin employed. The drug release was lower from the resins with higher content of sulfonic group due to the increase in the diffusive path depth. The drug release was a little lower in stimulated gastric fluid （SGF） than in stimulated intestinal fluids （SIF）. The basic groups, ionized to a little greater extent in SGF and preferred binding with the resin rather than releasing. Hence, the differently sulfonated resins could be utilized as novel carriers for drug delivery.展开更多
Natural gas hydrate inhibitor has been serving the oil and gas industry for many years. The development and search for new inhibitors remain the focus of research. In this study, the solution polymerization method was...Natural gas hydrate inhibitor has been serving the oil and gas industry for many years. The development and search for new inhibitors remain the focus of research. In this study, the solution polymerization method was employed to prepare poly(N-vinyl caprolactam-co-butyl methacrylate)(P(VCap-BMA)), as a new kinetic hydrate inhibitor(KHI). The inhibition properties of P(VCap-BMA) were investigated by tetrahydrofuran(THF) hydrate testing and natural gas hydrate forming and compared with the commercial KHIs. The experiment showed that PVCap performed better than copolymer P(VCap-BMA). However,low doses of methanol or ethylene glycol are compounded with KHIs. The compounding inhibitors show a synergistic inhibitory effect. More interesting is the P(VCap-BMA)-methanol system has a better inhibitory effect than the PVCap-methanol system. 1% P(VCap-BMA) + 5% methanol presented the best inhibiting performance at subcooling 10.3 °C, the induction time of natural gas hydrate was 445 min.Finally, the interaction between water and several dimeric inhibitors compared by natural bond orbital(NBO) analyses and density functional theory(DFT) indicated that inhibitor molecules were able to form the hydrogen bond with the water molecules, which result in gas hydrate inhibition. These exciting properties make the P(VCap-BMA) compound hydrate inhibitor promising candidates for numerous applications in the petrochemical industry.展开更多
Objective To establish the model of human bronchial epithelial cells （16HBE） malignant transformation induced by glycidyl methacrylate （GMA） and define the different methylation genes at different stages. Methods ...Objective To establish the model of human bronchial epithelial cells （16HBE） malignant transformation induced by glycidyl methacrylate （GMA） and define the different methylation genes at different stages. Methods DNA was extracted at different 16HBE malignant phases and methylation at different stages were detected using Methylation chip of Promoter Microarray Methylation＇. Methylation-specific PCR （MSP） was methylation status of some genes, and then compared with the control groups. changes of genes DNA ＇NimbleGen HG18 CpG used to observe the Results The result showed that GMA induced 16HBE morphorlogical transformation at the dose of 8 I^g/mL, and cell exposed to GMA had 1 374 genes in protophase, 825 genes in metaphase, 1 149 genes in anaphase, respectively; 30 genes are all methylation in the 3 stages; 318 genes in protophase but not in metaphase and anaphase; 272 genes in metaphase but not in protophase and anaphase; 683 genes in anaphase but not in metaphase and protophase; 73 genes in protophase and metaphase but not in anaphase; 67 genes in protophase and anaphase but not in metaphase; 59 genes in metaphase and anaphase but not in protophase. Conclusion The pattern of DNA methylation could change in the process of 16HBE induced by GMA.展开更多
In this study, commercial biaxially oriented polypropylene （BOPP）, polyvinyl chlo- ride （PVC） and poly （methyl methacrylate） （PMMA） films were treated with nitrogen plasma over different exposure times in a Py...In this study, commercial biaxially oriented polypropylene （BOPP）, polyvinyl chlo- ride （PVC） and poly （methyl methacrylate） （PMMA） films were treated with nitrogen plasma over different exposure times in a Pyrex tube surrounded by a DC variable magnetic field. The chemi- cal changes that appeared on the surface of the samples were investigated using Fourier transform infrared （FT4R） spectroscopy and attenuated total reflectance Fourier transform infrared （ATR- FTIR） spectroscopy after treatment for 2 min, 4 min and 6 rain in a nitrogen plasma chamber. Effects of the plasma treatment on the surface topographies and contact angles of the untreated and plasma treated films were also analyzed by atomic force microscopy （AFM） and a contact angle measuring system. The results show that the plasma treated films become more hydrophilic with an enhanced wettability due to the formation of some new polar groups on the surface of the treated films. Moreover, at higher exposure times, the total surface energy in all treated films increased while a reduction in contact angle occurred. The behavior of surface roughness in each sample was completely different at higher exposure times.展开更多
To functionalize poly（vinyl chloride）（PVC） for various applications, monomers containing tertiary amine group are incorporated into PVC via atom transfer radical polymerization（ATRP） initiated by the labile chlo...To functionalize poly（vinyl chloride）（PVC） for various applications, monomers containing tertiary amine group are incorporated into PVC via atom transfer radical polymerization（ATRP） initiated by the labile chlorines in their backbones. The kinetics of synthesis was carefully investigated, and it is proven that the grafting polymerization process can be effectively controlled by regulating the reaction time. The membranes are fabricated using PVC and copolymers by non-solvent induced phase separation（NIPS） process. The hydrophilicity and pore structure of copolymer membranes were enhanced as well, these membranes are endowed with positive charge. When PDMA%（i.e., the PDMA weight percentage in copolymer） is 31.1%, the flux and Victoria blue B rejection are 26.0 L·m·^-2·h^-1（0.5 MPa） and 91.2%, respectively. Thus, the newly synthesized polymer is proven to be a promising material for dye separation with positive charges.展开更多
BACKGROUND In children with osteosarcoma around the knee joint without epiphysis involvement,joint-sparing surgery seems to be an ideal way to retain knee joint function.However,there are two points of debate with reg...BACKGROUND In children with osteosarcoma around the knee joint without epiphysis involvement,joint-sparing surgery seems to be an ideal way to retain knee joint function.However,there are two points of debate with regard to the technique:How to accurately achieve a safe surgical margin,and how to achieve intercalary reconstruction of the massive bone defect following resection of the tumor.CASE SUMMARY We present the case of an 8-year-old girl with osteosarcoma of the distal femur without involvement of the epiphysis.Epiphyseal distraction was applied to separate the epiphysis and metaphysis,and this provided a safe surgical margin.The massive bone defect was reconstructed with a custom-made antibioticloaded polymethyl methacrylate(PMMA)construct combined with a free nonvascularized fibular graft.Six months after surgery,bone union between the autograft and host bone was confirmed in both the proximal and distal femur by computer tomography(CT)examination.Moreover,considerable callus formation was found around the PMMA construct.After 28 mo of follow-up,there was no sign of recurrence or metastasis.The patient could walk without any aid and carry out her daily life activities satisfactorily.CONCLUSION In cases of osteosarcoma without epiphysis involvement,epiphyseal distraction can be easily applied to obtain a safe margin.Hybrid reconstruction with an antibiotic-loaded PMMA construct combined with a free non-vascularized fibular graft has the advantages of being easy to manufacture,less time-consuming to place,and less likely to get infected,while also ensuring bone union.Our case provides an alternative technique for biological reconstruction after joint-sparing surgery in patients with osteosarcoma around the knee without epiphyseal involvement.展开更多
Polypropylene/poly（butyl methacrylate） （PP/PBMA） blends were prepared by diffusion and subseqtuent polymerization＇of butyl methacrylate （BMA） in commercial isotactic polypropylene （iPP） pellets. The diffusion...Polypropylene/poly（butyl methacrylate） （PP/PBMA） blends were prepared by diffusion and subseqtuent polymerization＇of butyl methacrylate （BMA） in commercial isotactic polypropylene （iPP） pellets. The diffusion kinetics, diametrical distribution of PBMA in a pellet and phase morphology of a typical PP/PBMA blend were investigated.展开更多
A novel tetrafunctional initiator, C [CH_2O (CH_2)_3 OOCCH(Br)CH_3]_4 (1), was synthesized through the reaction oftetraol with α-bromopropionyl chloride, and then was used as initiator of atom transfer radical polyme...A novel tetrafunctional initiator, C [CH_2O (CH_2)_3 OOCCH(Br)CH_3]_4 (1), was synthesized through the reaction oftetraol with α-bromopropionyl chloride, and then was used as initiator of atom transfer radical polymerization (ATRP) in thepreparation of 4-armed polystyrene (PSt) with narrow polydispersity. The structure, molecular weight and molecular weightdistribution (MWD) of each arm were studied by ~1H-NMR and GPC data of hydrolyzed products of the 4-armed PSt. TheATRP of St using 1/CuBr/bpy as initiator system is of 'living' character based on the following evidence: narrow MWD,constant concentration of chain radical during the polymerization, control of molecular weight by the molar ratio of monomerconsumed to 1. The 4-armed poly(St-b-p-nitrophenyl methacrylate) [poly(St-b-NPMA)] was prepared by the ATRP ofNPMA using 4-armed PSt with terminal bromine as the initiator, and characterized by FT-IR, ~1H-NMR spectra and GPCcurves. The micelles with PSt as core, and PNPMA as shell were formed by dropping DMSO into a solution of 4-armedpoly(St-b-NPMA) in DMF, as proved by laser light scatter (LLS) method.展开更多
Rapid and simultaneous in situ detection of multi-components is extremely crucial for the real-time monitoring of nutrients in fruits.Herein,a facile and user-friendly poly(carboxybetaine methacrylate)-coated paper-ba...Rapid and simultaneous in situ detection of multi-components is extremely crucial for the real-time monitoring of nutrients in fruits.Herein,a facile and user-friendly poly(carboxybetaine methacrylate)-coated paper-based microfluidic device(pCBMA-μPAD)has been exploited to synchronously identify and semi-quantify vitamin C.glucose,sucro se and fructose in fruits.The pCBMA was successfully grafted from the surface of paper sensor using a co nvenient and robust method,which was confirmed by Fourier transform infrared spectroscopy(FT-IR)and X-ray photoelectron spectrometry(XPS).The superior hydrophilicity and ultra-low fouling of pCBMA endowed the pCBMA-μPAD with remarkably rapid response(3 min),high sensitivity,good linear relationship and low detection limit(LOD)(vitamin C:y=33.809+5.175 x,R^2=0.993,LOD=0.179 mmol/L;glucose:y=-0.113+30.0661 g(x),R^2=0.988,LOD=0.095 mmol/L;sucrose:y--5.334+34.858 lg(x),R^2=0.996,LOD=0.097 mmol/L;fructose:y=4.996+23.325 lg(x),R^2=0.994,LOD=0.140 mmol/L).Furthermore,satisfactory results were yielded in the detection of these nutrients in 9 fruits,which were much agreed well with those obtained by spectrophotometry.Such a portable and versatile pCBMA-μPAD will pro foundly shape the future of food analysis,especially for the assessment of food quality and nutrition in the process of agricultural production and marketing.展开更多
Hydrogen nuclear magnetic resonance(H1-NMR) and X-ray diffractometer(XRD) were used to characterize the molecular and crystal structure of lead methacrylate [Pb(MAA)_(2)] which was produced by the double decomposition...Hydrogen nuclear magnetic resonance(H1-NMR) and X-ray diffractometer(XRD) were used to characterize the molecular and crystal structure of lead methacrylate [Pb(MAA)_(2)] which was produced by the double decomposition reaction of lead oxide and methacrylic acid.Isothermal analysis and Kelen-T(u|")dos(K-T) method were used to study the self-polymerization kinetic and the monomer reactivity ratios of Pb(M A A)_(2) and methyl methacrylate(MMA),respectively.By the ternary polymerization method of bulk casting using MMA,Pb(MAA)_(2) and gadolinium methacrylate(Gd(MAA)_(3)) as monomers,we prepared the plexiglass which have neutron and X-ray protection property.The results show that the polymerization rate(R_(p)) is expressed as Rp=K[M]^(1.02)[I]^(0.37) below the 10% conversion rate at 70℃,where K is the polymerization rate constant.And in the N,N-dimethylformamide(DMF) solution,the activation energy required for Pb(MAA)_(2) to initiate self-polymerization by the free radicals is 74.99 kJ·mol^(-1).The reactivity ratios of r1 [Pb(MAA)_(2)] and r2(MMA) are 3.767 and0.166.As the thickness of the material increases,the X-ray and thermal neutron shielding ability of the plexiglass containing gadolinium and lead is getting better and better.展开更多
文摘Traditional biodiesel production primarily uses methanol as the acyl acceptor,but its toxicity to lipase increases process complexity and operational difficulty elevate manufacturing costs.This study aimed to explore a new method for enzymatic synthesis of biodiesel with methyl methacrylate(MMA)as acyl acceptor.Meanwhile,a 1,3-position specific lipase Lipozyme RM IM was applied as biocatalyst,which enables simultaneous production of biodiesel(FAMEs)and methacrylate fatty acid glycerides(MFAGs)via specific sn-1,3 transesterification of MMA with triglyceride.Under the optimal reaction conditions:temperature of 50℃,molar ratio of 4:1 for MMA to triglyceride,enzyme dosage of 7.5%(mass),and an extra water addition of 0.5%(mass);triglyceride conversion rate of 97%,and FAMEs yield of 65%could be obtained.Simultaneously,the multistage short-path distillation and column chromatographic method were combined used for the separation of the mixed products.Finally,the purity of FAME,MFADG,DMFAG,and MMFAG were 98%,97.8%,95.3%,and 81.78%,respectively.In this new approach,MMA demonstrates lower toxicity to lipases,allowing for straightfo rward addition of all the substrates without complex addition process,and enhancing operational feasibility.Meanwhile,the by-products of MFAGs could be applied as monomers in varnishes and protective coatings,which increased the value of the products.Thus,this investigation providing an alternative way to produce biodiesel,and providing a new pathway for the sustainable development of biodiesel.
文摘Polybutylacrylate (PBA)/poly(methyl methacrylate) (PMMA) core-shell elastic particles (CSEP), whose rubbery core diameter ranged from 0.08 μm to 1.38μm, were synthesized by using conventional emulsion polymerization, multi-step emulsion polymerization, and soapless polymerization. Allyl methacylate (ALMA) and ethylene glycol dimethacrylate (EGDMA) were selected as crosslinking reagents for core polymerization. Methacrylic acid (MAA) was used as functional co-monomer with methyl methacrylate as shell component. The content of vinyl groups in PBA rubbery core increased with the amount of crosslinking reagents. The core-shell ratio affected great on the morphology of the complex particles. Furthermore, the amounts of carboxyl on the surface of core-shell particles, copolymerized with acrylic acid, were determined by potentiometric titration. Results showed that methylacrylic acid was distributed mostly on the surface of particles.
基金This work was supported by the National Natural Science Foundation of China (Grants 20174001, 29992590-4) and the Ministry of Education of China for the teaching and research award fund for outstanding young teacher in higher education institutions.
文摘Two new chiral ionic liquids, 1 -((-)-menthoxycarbonylmethylene)-3-methylimidazolium hexafluorophosphateand 1-((-)-menthoxycarbonylmethylene)-3-hexadecylimidazolium hexafluorophosphate, were designed an d prepared. Theirchemical structures were characterized by ~1H-NMR. Reverse atom transfer radical polymerization of methyl methacrylate(MMA) in these two ionic liquids was carried out using AIBN/CuCl_2/bipy as the initiating system. The resultant well-definedpolymethyl methacrylate (PMMA) was employed as a macroinitiator to induce the atom transfer radical polymerization ofmenthyl methacrylate (MnMA) in chlorobenzene, which yielded a PMMA-b-PMnMA diblock copolymer with narrow polydispersity.
基金supported by the National Key R&D Program of China(No.2018YFA0703000)the National Natural Science Foundation of China(Nos.82071564,82072412,and 81772326)+1 种基金the Fundamental Research Program Funding of Ninth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine(No.JYZZ070)Project of Shanghai Science and Technology Commission(No.19XD1434200/18431903700)。
文摘Poly methyl methacrylate(PMMA)bone cement is used in augmenting and stabilizing fractured vertebral bodies through percutaneous vertebroplasty(PVP)and percutaneous kyphoplasty(PKP).However,applications of PMMA bone cement are limited by the high elasticity modulus of PMMA,its low biodegradability,and its limited ability to regenerate bone.To improve PMMA bio activity and biodegradability and to modify its elasticity modulus,we mixed PMMA bone cement with oxidized hyaluronic acid and carboxymethyl chitosan in situ cross-linking hydrogel loaded with bone morphogenetic protein-2(BMP-2)to achieve novel hybrid cement.These fabric ated PMMA-hydrogel hybrid cements exhibited lower setting temperatures,a lower elasticity modulus,and better biodegradability and biocompatibility than that of pure PMMA cement,while retaining acceptable setting times,mechanical strength,and inj ectability.In addition,we detected release of BMP-2 from the PMMA-hydrogel hybrid cements,significantly enhancing in vitro osteogenesis of bone marrow mesenchymal stem cells by up-regulating the gene expression of Runx2,Coll,and OPN.Use of PMMA-hydrogel hybrid cements loaded with BMP-2 on rabbit femoral condyle bone-defect models revealed their biodegradability and enhanced bone formation.Our study demonstrated the favorable mechanical properties,biocompatibility,and biodegradability of fabricated PMMA-hydrogel hybrid cements loaded with BMP-2,as well as their ability to improve osteogenesis,making them a promising material for use in PKP and PVP.
基金This work was supported by a grant from the National Natural Science Foundation of China (grant no. 39840017).
文摘Objective To evaluate the genotoxic and nongenotoxic effects of short-term exposure to glycidyl mathacrylate (GMA) on human lung fibroblast cells (2BS cells) in vitro. Methods DNA strand breakage was determined by single cell gel electrophoresis, and DNA ladder formation assay and flow cytometric analysis were carried out to detect apoptic responses of cells to GMA exposure. The HPRT gene mutation assay was used to evaluate the mutagenicity, and the effect of GMA on gap junctional intercellular communication (GJIC) in the exposed cells was examined with the scrape loading/dye transfer technique. The ability of GMA to transform 2BS cells was also tested by an in vitro cell transformation assay. Results Exposure to GMA resulted in a dose-dependent increase in DNA strand breaks but not apoptic responses. GMA was also shown to significantly induce HPRT gene mutations and morphological transformation in 2BS cells in vitro. In contrast, GMA produced a concentration-dependent inhibition of GJIC. Conclusions GMA elicits both genotoxic and nongenotoxic effects on 2BS cells in vitro. The induction of DNA damage and gene mutations and inhibition of GJIC by GMA may casually contribute to GMA-induced cell transformation.
文摘Poly （ethyleneglycol monomethylether） methacrylate （PEGMM）was synthesized by means of the reaction of methacrylyl chloride with sodium monomethylpolyethyleneglycoxide and was characterized by FTIR,;H-NMR,and ultraviolet spectrometries. A series of poly （vinyl alcohol）-graft-PEGMM （PVA-g-PEGMM ）and methyl methacrylate-PEGMM copolymer （PMMA-PEGMM） were prepared and tested for antithrombogenicity in vitro. The results indicate that the antithrombogenicity of the copolymers basically increases with the increasing of the DP of polyoxyethylene （POE） chain and tends to a plateau after the DP around 114,i.e. the long chain structure of POE is favourable to the antithrombogenicityof its copolymers ;moreover, the extent of the improvement ofantithrombogenicity also relates to the PEGMM content of the copolymers and the kind of the matrix that the POE chains are located on. These results are consistent with the anticipation of the hypothesis of maintaining proteins normal conformations for blood compatible bioraaterials.
文摘Synthesis and characterization of the copolymers （PAG） of α-methyl styrene （AMS） and glycidyl methacrylate （GMA） are presented. The copolymers of PAG were characterized by gel permeation chromatography （GPC）, Fourier transform infrared spectroscopy （FTIR）, nuclear magnetic resonance （^1H-NMR） and thermogravimetery （TG）. Based on the copolymer compositions determined by ^1H-NMR, the reactivity ratios of AMS and GMA were found to be 0.105 ± 0.012 and 0.883 ± 0.046 respectively by Kelen-Tudos method. TG revealed that thermal stability of the copolymers decreased with increasing the AMS content in the copolymers, which indicated that the degradation was mainly caused by the chain scission of AMS-containing structures. Under heating, the copolymers depolymerize at their weak bonds and form chain radicals, which could further initiate other chemical reactions.
文摘In this study, a UV-curable polysiloxane methacrylate （PSMA） was synthesized by a one-step method. The reaction was catalyzed by chloroplatinic acid between polymethylhydrosiloxane （PMHS） and hydroxyethyl methacrylate （HEMA）, as proved by FTIR and ^1H-NMR. The preliminary results indicate that the obtained UV-cured PSMA film has very good thermal stability, excellent transparency and satisfactory tensile strength. Our work provides a simple but efficient way to prepare UV-curable PSMA, which may find potential applications in UV-curing optical fiber, metal and glass coating and other fields.
文摘A novel nanomagnetic organogel was synthesized by in situ emulsion polymerization-crosslinking method using dodecyl methacrylate(DDMA) and styrene(St) as monomers, divinylbenzene(DVB) as a crosslinking agent, azobisisobutyronitrile(AIBN) as an initiator, and Fe_3O_4 as a nanomagnetic particle. Modification of the network was carried out by inclusion of the multi-walled carbon nanotubes(MWCNT) into the organogel matrix. The structure of the nanocomposite was characterized using FTIR spectroscopy, SEM,TEM, TGA/DTG, VSM, and BET analysis. The effects of various parameters such as the amount of crosslinker, initiator, Fe_3O_4, and reaction time as well as monomer ratio on the oil absorption of the organogel were studied. The synthesized organogel can absorb about35.5, 22.1, 29.86, 14.58, 17.6, 15.3, and 13.7 g·g^(-1) of CHCl_3, toluene, CH_2Cl_2, hexane, crude oil, gasoline, and diesel oil, under the optimized polymerization conditions, respectively. The nanocomposite organogels can be easily separated by a magnetic field after absorption of organic solvents.
基金supported by the National Science Foundation for Distinguished Young Scholars of China(Grant No.51925403)Major Research plan of the National Natural Science Foundation of China(Grant No.91934302)+2 种基金the National Science Foundation of China(21676052,21606042)Independent Innovation Fund of Tianjin University(2023XJD0050)Funding for National Key R&D Program of China(2022YFB3808800).
文摘Preparing polymeric coatings with well corrosion resistance and high thermal conductivity(TC)to prolong operational life and ensure service reliability of heat conductive metallic materials has long been a substantive and urgent need while a difficult task.Here we report a multifunctional epoxy composite coating(F-CB/CEP)by synthesizing cerium methacrylate and ingeniously using it as a novel curing agent with corrosion inhibit for epoxy resin and modifier for boron nitride through"cation-π"interaction.The prepared F-CB/CEP coating presents a high TC of 4.29 W m^(−1)K^(−1),which is much higher than other reported anti-corrosion polymer coatings and thereby endowing metal materials coated by this coating with outstanding thermal management performance compared with those coated by pure epoxy coating.Meanwhile,the low-frequency impedance remains at 5.1×10^(11)Ωcm^(2)even after 181 days of immersion in 3.5 wt%NaCl solution.Besides,the coating also exhibits well hydrophobicity,self-cleaning properties,temperature resistance and adhesion.This work provides valuable insights for the preparation of high-performance composite coatings with potential to be used as advanced multifunctional thermal management materials,especially for heat conduction metals protection.
基金The University Grants Commission,New Delhi for its funding of this workIndian Institute of Science,Bangalore for its instrumental support+2 种基金Department of Physics,Sri Venkateswara University,Tirupathi,for its assistance in the SEM studyUGC,New Delhi for its support under SAPDST,New Delhi for its support under FIST
文摘2-Acryloxyacetophenone （AAP） was prepared and subjected to suspension polymerization with methyl methacrylate （MMA） using azobisisobutyronitrile （AIBN） as free radical initiator. The differently sulfonated AAP-MMA cross-linked copolymer cationic exchange resins were prepared by sulfonation with concentrated sulphuric acid at 70 ~C. Several characteristics of the prepared resins were evaluated, i.e. FTIR, the ion-exchange capacity （IEC）, thermo gravimetric analysis （TGA）, particle size distribution and microscopic morphology. The resin characteristics were altered with degree of sulfonation, providing that differently sulfonated resins could be prepared. The behavior of atenolol （ATL） loading and in vitro release in the USP stimulated gastric and intestinal fluids of the obtained resins were evaluated. The drug loaded in the resin increased with increasing degree of sulfonation and hence the drug binding site in resin employed. The drug release was lower from the resins with higher content of sulfonic group due to the increase in the diffusive path depth. The drug release was a little lower in stimulated gastric fluid （SGF） than in stimulated intestinal fluids （SIF）. The basic groups, ionized to a little greater extent in SGF and preferred binding with the resin rather than releasing. Hence, the differently sulfonated resins could be utilized as novel carriers for drug delivery.
基金supported by the Key Science and Technology Program of Shaanxi Province (2014K10-03)。
文摘Natural gas hydrate inhibitor has been serving the oil and gas industry for many years. The development and search for new inhibitors remain the focus of research. In this study, the solution polymerization method was employed to prepare poly(N-vinyl caprolactam-co-butyl methacrylate)(P(VCap-BMA)), as a new kinetic hydrate inhibitor(KHI). The inhibition properties of P(VCap-BMA) were investigated by tetrahydrofuran(THF) hydrate testing and natural gas hydrate forming and compared with the commercial KHIs. The experiment showed that PVCap performed better than copolymer P(VCap-BMA). However,low doses of methanol or ethylene glycol are compounded with KHIs. The compounding inhibitors show a synergistic inhibitory effect. More interesting is the P(VCap-BMA)-methanol system has a better inhibitory effect than the PVCap-methanol system. 1% P(VCap-BMA) + 5% methanol presented the best inhibiting performance at subcooling 10.3 °C, the induction time of natural gas hydrate was 445 min.Finally, the interaction between water and several dimeric inhibitors compared by natural bond orbital(NBO) analyses and density functional theory(DFT) indicated that inhibitor molecules were able to form the hydrogen bond with the water molecules, which result in gas hydrate inhibition. These exciting properties make the P(VCap-BMA) compound hydrate inhibitor promising candidates for numerous applications in the petrochemical industry.
基金supported by National Natural Science Foundation of China(81072318)
文摘Objective To establish the model of human bronchial epithelial cells （16HBE） malignant transformation induced by glycidyl methacrylate （GMA） and define the different methylation genes at different stages. Methods DNA was extracted at different 16HBE malignant phases and methylation at different stages were detected using Methylation chip of Promoter Microarray Methylation＇. Methylation-specific PCR （MSP） was methylation status of some genes, and then compared with the control groups. changes of genes DNA ＇NimbleGen HG18 CpG used to observe the Results The result showed that GMA induced 16HBE morphorlogical transformation at the dose of 8 I^g/mL, and cell exposed to GMA had 1 374 genes in protophase, 825 genes in metaphase, 1 149 genes in anaphase, respectively; 30 genes are all methylation in the 3 stages; 318 genes in protophase but not in metaphase and anaphase; 272 genes in metaphase but not in protophase and anaphase; 683 genes in anaphase but not in metaphase and protophase; 73 genes in protophase and metaphase but not in anaphase; 67 genes in protophase and anaphase but not in metaphase; 59 genes in metaphase and anaphase but not in protophase. Conclusion The pattern of DNA methylation could change in the process of 16HBE induced by GMA.
文摘In this study, commercial biaxially oriented polypropylene （BOPP）, polyvinyl chlo- ride （PVC） and poly （methyl methacrylate） （PMMA） films were treated with nitrogen plasma over different exposure times in a Pyrex tube surrounded by a DC variable magnetic field. The chemi- cal changes that appeared on the surface of the samples were investigated using Fourier transform infrared （FT4R） spectroscopy and attenuated total reflectance Fourier transform infrared （ATR- FTIR） spectroscopy after treatment for 2 min, 4 min and 6 rain in a nitrogen plasma chamber. Effects of the plasma treatment on the surface topographies and contact angles of the untreated and plasma treated films were also analyzed by atomic force microscopy （AFM） and a contact angle measuring system. The results show that the plasma treated films become more hydrophilic with an enhanced wettability due to the formation of some new polar groups on the surface of the treated films. Moreover, at higher exposure times, the total surface energy in all treated films increased while a reduction in contact angle occurred. The behavior of surface roughness in each sample was completely different at higher exposure times.
基金financially supported by the National 863 Program(No.2012AA03A602)National 973 Program(No.2009CB623402)the National Natural Science Foundation of China(No.U1134002)
文摘To functionalize poly（vinyl chloride）（PVC） for various applications, monomers containing tertiary amine group are incorporated into PVC via atom transfer radical polymerization（ATRP） initiated by the labile chlorines in their backbones. The kinetics of synthesis was carefully investigated, and it is proven that the grafting polymerization process can be effectively controlled by regulating the reaction time. The membranes are fabricated using PVC and copolymers by non-solvent induced phase separation（NIPS） process. The hydrophilicity and pore structure of copolymer membranes were enhanced as well, these membranes are endowed with positive charge. When PDMA%（i.e., the PDMA weight percentage in copolymer） is 31.1%, the flux and Victoria blue B rejection are 26.0 L·m·^-2·h^-1（0.5 MPa） and 91.2%, respectively. Thus, the newly synthesized polymer is proven to be a promising material for dye separation with positive charges.
基金Supported by National Natural Science Foundation of China,No.81301671
文摘BACKGROUND In children with osteosarcoma around the knee joint without epiphysis involvement,joint-sparing surgery seems to be an ideal way to retain knee joint function.However,there are two points of debate with regard to the technique:How to accurately achieve a safe surgical margin,and how to achieve intercalary reconstruction of the massive bone defect following resection of the tumor.CASE SUMMARY We present the case of an 8-year-old girl with osteosarcoma of the distal femur without involvement of the epiphysis.Epiphyseal distraction was applied to separate the epiphysis and metaphysis,and this provided a safe surgical margin.The massive bone defect was reconstructed with a custom-made antibioticloaded polymethyl methacrylate(PMMA)construct combined with a free nonvascularized fibular graft.Six months after surgery,bone union between the autograft and host bone was confirmed in both the proximal and distal femur by computer tomography(CT)examination.Moreover,considerable callus formation was found around the PMMA construct.After 28 mo of follow-up,there was no sign of recurrence or metastasis.The patient could walk without any aid and carry out her daily life activities satisfactorily.CONCLUSION In cases of osteosarcoma without epiphysis involvement,epiphyseal distraction can be easily applied to obtain a safe margin.Hybrid reconstruction with an antibiotic-loaded PMMA construct combined with a free non-vascularized fibular graft has the advantages of being easy to manufacture,less time-consuming to place,and less likely to get infected,while also ensuring bone union.Our case provides an alternative technique for biological reconstruction after joint-sparing surgery in patients with osteosarcoma around the knee without epiphyseal involvement.
基金support from the National Natural Science Foundation of China (No.51173095)
文摘Polypropylene/poly（butyl methacrylate） （PP/PBMA） blends were prepared by diffusion and subseqtuent polymerization＇of butyl methacrylate （BMA） in commercial isotactic polypropylene （iPP） pellets. The diffusion kinetics, diametrical distribution of PBMA in a pellet and phase morphology of a typical PP/PBMA blend were investigated.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 29774027).
文摘A novel tetrafunctional initiator, C [CH_2O (CH_2)_3 OOCCH(Br)CH_3]_4 (1), was synthesized through the reaction oftetraol with α-bromopropionyl chloride, and then was used as initiator of atom transfer radical polymerization (ATRP) in thepreparation of 4-armed polystyrene (PSt) with narrow polydispersity. The structure, molecular weight and molecular weightdistribution (MWD) of each arm were studied by ~1H-NMR and GPC data of hydrolyzed products of the 4-armed PSt. TheATRP of St using 1/CuBr/bpy as initiator system is of 'living' character based on the following evidence: narrow MWD,constant concentration of chain radical during the polymerization, control of molecular weight by the molar ratio of monomerconsumed to 1. The 4-armed poly(St-b-p-nitrophenyl methacrylate) [poly(St-b-NPMA)] was prepared by the ATRP ofNPMA using 4-armed PSt with terminal bromine as the initiator, and characterized by FT-IR, ~1H-NMR spectra and GPCcurves. The micelles with PSt as core, and PNPMA as shell were formed by dropping DMSO into a solution of 4-armedpoly(St-b-NPMA) in DMF, as proved by laser light scatter (LLS) method.
基金financially supported by the National Natural Science Foundation of China(Nos.31701678,31801638)the Key Project of Shanghai Agriculture Prosperity through Science and Technology(No.2019-02-08-00-15-F01147)+1 种基金the Key Science and Technology Project of Henan(No.172102310586)China Post-Doctoral Science Foundation(No.2018T110338)。
文摘Rapid and simultaneous in situ detection of multi-components is extremely crucial for the real-time monitoring of nutrients in fruits.Herein,a facile and user-friendly poly(carboxybetaine methacrylate)-coated paper-based microfluidic device(pCBMA-μPAD)has been exploited to synchronously identify and semi-quantify vitamin C.glucose,sucro se and fructose in fruits.The pCBMA was successfully grafted from the surface of paper sensor using a co nvenient and robust method,which was confirmed by Fourier transform infrared spectroscopy(FT-IR)and X-ray photoelectron spectrometry(XPS).The superior hydrophilicity and ultra-low fouling of pCBMA endowed the pCBMA-μPAD with remarkably rapid response(3 min),high sensitivity,good linear relationship and low detection limit(LOD)(vitamin C:y=33.809+5.175 x,R^2=0.993,LOD=0.179 mmol/L;glucose:y=-0.113+30.0661 g(x),R^2=0.988,LOD=0.095 mmol/L;sucrose:y--5.334+34.858 lg(x),R^2=0.996,LOD=0.097 mmol/L;fructose:y=4.996+23.325 lg(x),R^2=0.994,LOD=0.140 mmol/L).Furthermore,satisfactory results were yielded in the detection of these nutrients in 9 fruits,which were much agreed well with those obtained by spectrophotometry.Such a portable and versatile pCBMA-μPAD will pro foundly shape the future of food analysis,especially for the assessment of food quality and nutrition in the process of agricultural production and marketing.
基金financially supported by the Aviation Science Fund(No.2017ZF25)the Graduate Research Innovation Fund of Yangzhou University(No.XKYCX19066)。
文摘Hydrogen nuclear magnetic resonance(H1-NMR) and X-ray diffractometer(XRD) were used to characterize the molecular and crystal structure of lead methacrylate [Pb(MAA)_(2)] which was produced by the double decomposition reaction of lead oxide and methacrylic acid.Isothermal analysis and Kelen-T(u|")dos(K-T) method were used to study the self-polymerization kinetic and the monomer reactivity ratios of Pb(M A A)_(2) and methyl methacrylate(MMA),respectively.By the ternary polymerization method of bulk casting using MMA,Pb(MAA)_(2) and gadolinium methacrylate(Gd(MAA)_(3)) as monomers,we prepared the plexiglass which have neutron and X-ray protection property.The results show that the polymerization rate(R_(p)) is expressed as Rp=K[M]^(1.02)[I]^(0.37) below the 10% conversion rate at 70℃,where K is the polymerization rate constant.And in the N,N-dimethylformamide(DMF) solution,the activation energy required for Pb(MAA)_(2) to initiate self-polymerization by the free radicals is 74.99 kJ·mol^(-1).The reactivity ratios of r1 [Pb(MAA)_(2)] and r2(MMA) are 3.767 and0.166.As the thickness of the material increases,the X-ray and thermal neutron shielding ability of the plexiglass containing gadolinium and lead is getting better and better.
