Addressing the critical challenges of viscosity loss and barite sag in synthetic-based drilling fluids(SBDFs)under high-temperature,high-pressure(HTHP)conditions,this study innovatively developed a hyperbranched amide...Addressing the critical challenges of viscosity loss and barite sag in synthetic-based drilling fluids(SBDFs)under high-temperature,high-pressure(HTHP)conditions,this study innovatively developed a hyperbranched amide polymer(SS-1)through a unique stepwise polycondensation strategy.By integrating dynamic ionic crosslinking for temperature-responsive rheology and rigid aromatic moieties ensuring thermal stability beyond 260℃,SS-1 achieves a molecular-level breakthrough.Performance evaluations demonstrate that adding merely 2.0 wt% SS-1 significantly enhances key properties of 210℃-aged SBDFs:plastic viscosity rises to 45 mPa⋅s,electrical stability(emulsion voltage)reaches 1426 V,and the sag factor declines to 0.509,outperforming conventional sulfonated polyacrylamide(S-PAM,0.531)by 4.3%.Mechanistic investigations reveal a trifunctional synergistic anti-sag mechanism involving electrostatic adsorption onto barite surfaces,hyperbranched steric hindrance,and colloid-stabilizing network formation.SS-1 exhibits exceptional HTHP stabilization efficacy,substantially surpassing S-PAM,thereby providing an innovative molecular design strategy and scalable solution for next-generation high-performance drilling fluid stabilizers.展开更多
Anion-exchange membrane water electrolysers(AEMWEs)and fuel cells(AEMFCs)are critical technologies for converting renewable resources into green hydrogen(H_(2)),where anion-exchange membranes(AEMs)play a vital role in...Anion-exchange membrane water electrolysers(AEMWEs)and fuel cells(AEMFCs)are critical technologies for converting renewable resources into green hydrogen(H_(2)),where anion-exchange membranes(AEMs)play a vital role in efficiently transporting hydroxide ions(OH^(-))and minimizing fuel crossover,thus enhancing overall efficiency.While conventional AEMs with linear,side-chain,and block polymer architectures show promise through functionalization,their long-term performance remains a concern.To address this,hyperbranched polymers offer a promising alternative due to their three-dimensional structure,higher terminal functionality,and ease of functionalization.This unique architecture provides interconnected ion transport pathways,fractional free volume,and enhanced long-term stability in alkaline environments.Recent studies have achieved conductivities as high as 304.5 mS cm^(-1),attributed to their improved fractional free volume and microphase separation in hyperbranched AEMs.This review explores the chemical,mechanical,and ionic properties of hyperbranched AEMs in AEMFCs and assesses their potential for application in AEMWEs.Strategies such as blending and structural functionalisation have significantly improved the properties by promoting microphase separation and increasing the density of cationic groups on the polymer surface.The review provides essential insights for future research,highlighting the challenges and opportunities in developing high-performance hyperbranched AEMs to advance hydrogen energy infrastructure.展开更多
Functional hyperbranched polymers,as an important class of materials,are widely applied in diverse areas.Therefore,the development of simple and efficient reactions to prepare hyperbranched polymers is of great signif...Functional hyperbranched polymers,as an important class of materials,are widely applied in diverse areas.Therefore,the development of simple and efficient reactions to prepare hyperbranched polymers is of great significance.In this work,trialdehydes,diamines,and trimethylsilyl cyanide could easily undergo multicomponent polymerization under mild conditions,producing hyperbranched poly(α-aminonitrile)s with high molecular weights(M_(w) up to 4.87×10^(4))in good yields(up to 85%).The hyperbranched poly(α-aminonitrile)s have good solubility in commonly used organic solvents,high thermal stability as well as morphological stability.Furthermore,due to the numerous aldehyde groups in their branched chains,these hb-poly(α-aminonitrile)s can undergo one-pot,two-step,four-component post-polymerization with high efficiency.This work not only confirms the efficiency of our established catalyst-free multicomponent polymerization of aldehydes,amines and trimethylsilyl cyanide,but also provides a versatile and powerful platform for the preparation of functional hyperbranched polymeric materials.展开更多
An epoxy-terminated hyperbranched aromatic polyester (P3) was synthesized from a hyperbranched aromatic polyester containing carboxylic acid end groups (P1), which was derived from the condensation polymerization of t...An epoxy-terminated hyperbranched aromatic polyester (P3) was synthesized from a hyperbranched aromatic polyester containing carboxylic acid end groups (P1), which was derived from the condensation polymerization of the AB(2) monomer, 5-acetoxyisophthalic acid. Polymer P1 was converted into the polymeric acid chloride by reaction with thionyl chloride. The acid chloride was reacted with ethanol and glycidol to form a poly(ethyl ester) (P2) and an epoxy terminated material (P3), respectively. The reaction conditions in each step of these processes had to be controlled very carefully to avoid unwanted cross-linking reactions. The characterization of products and intermediates, including molecular weight distributions and thermal properties, are reported.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
A novel AB3-type monomer was prepared from gallic acid and DL-2-aminobutyric acid, and used for the synthesis of the biocompatible hyperbranched poly(ester-amide)s by self-polycondensation. The polymers were character...A novel AB3-type monomer was prepared from gallic acid and DL-2-aminobutyric acid, and used for the synthesis of the biocompatible hyperbranched poly(ester-amide)s by self-polycondensation. The polymers were characterized via FTIR and NMR spectroscopy and thermal analysis, and the average degree of branching of the polymers was estimated to be 0.75. The polymers with abundant acetyl end groups were found to be amorphous with lower intrinsic viscosity, better thermal stability and excellent solubility.展开更多
UV-curable hyperbranched polyurethane acrylate-polyurethane diacrylate/SiO2 dispersion （HBPUA-PUDA/SiO2） was prepared with isophorone diisocyanate （IPDI）, hyperbranched polyester Boltorn H20 （H20）, hydroxy-ethyl...UV-curable hyperbranched polyurethane acrylate-polyurethane diacrylate/SiO2 dispersion （HBPUA-PUDA/SiO2） was prepared with isophorone diisocyanate （IPDI）, hyperbranched polyester Boltorn H20 （H20）, hydroxy-ethyl acrylate （HEA）, polyethyleneglycol （PEG-200）and nano-SiO2. The UV curing kinetics of the films was investigated by FTIR. The results show that the curing speed of the films increases with the adding of nano-SiO2 and decreases with the adding of PUDA due to the slower chain movement. The thermal stability of the HBPUA-PUDA/SiO2 films was studied by using thermogravimetric analysis coupled with Fourier transform infrared spectroscopy （TGA/FTIR）. The results show that all films exhibit two degradation stages located at about 320 and 440℃ corresponding to the degradation for hard segments of urethane-acrylate and the degradation for soft segment and polyester core. In addition, the results from the analysis of TGA/FTIR also indicate that the decomposition temperature of HBPUA-PUDA/SiO2 film is 15℃ higher than that obtained for pure polymer. The degradation mechanism was proposed according to TGA/FTIR results.展开更多
Hyperbranched polymer with highly branched three-dimensional topological structure, a large number of end groups, and multifaceted functionalities have gained much attention, while polymers with aggregation-induced em...Hyperbranched polymer with highly branched three-dimensional topological structure, a large number of end groups, and multifaceted functionalities have gained much attention, while polymers with aggregation-induced emission(AIE) properties become a group of popular luminescent materials recently. The design and synthesis of AIE-active hyperbranched polymers, which combine the advantages of these two types of materials, are attractive but challenging. In this work, four hyperbranched poly(tetrahydropyrimidine)s were synthesized from the metal-free room temperature multicomponent tandem polymerization of diester group-activated internal alkyne,polyfunctional aromatic amines, and formaldehyde in methanol under the catalysis of acetic acid. Through different monomer combination and controlling the monomer loading order, hyperbranched polymers with various topological structures as well as sequences of different functional groups in the polymer backbone were obtained with high molecular weights(up to 3.0 × 10~4 g/mol) in high yields(up to 98%). The hyperbranched poly(tetrahydropyrimidine) emitted faintly in solution, while its luminescence was notably enhanced in the aggregated state, suggesting its typical aggregation-induced emission property. It is anticipated that the multicomponent polymerization may provide a synthetic platform for the construction of hyperbranched polyheterocycles with diverse structures and functionalities.展开更多
Polycyclotrimerization and polycoupling of acetylenic monomers respectively furnish hyperbranched polyarylenes and polyynes with high molecular weights （up to 1 × 10^6） in high yields （up to 99.9%）. The polym...Polycyclotrimerization and polycoupling of acetylenic monomers respectively furnish hyperbranched polyarylenes and polyynes with high molecular weights （up to 1 × 10^6） in high yields （up to 99.9%）. The polymers possess low intrinsic viscosities and high thermal stabilities, losing little of their weights when heated to 〉 400℃. Upon pyrolysis at 〉 800℃, the polymers graphitize with high char yields （up to 86%）. Hyperbranched polyarylenes efficiently emit deep-blue to blue-green lights with fluorescence quantum yields up to 98% and strongly attenuate intense laser pulses with optical power-limiting performances superior to that of C60, a well-known optical limiter. Poly（alkenephenylenes）, poly（aroylarylenes） and polyynes are readily cross-linkable by UV irradiation, serving as excellent photoresist materials for the generation of patterns with nanometer resolution. Thin films of hyperbranched polyynes exhibit very high refractive indexes （n up to 1.86）. The internal and terminal acetylene moieties of the polyynes readily form complexes with cobalt carbonyls, which can be transformed into soft ferromagnetic ceramics with high magnetic susceptibilities （Ms up to ca. 118 emu/g） and near-zero magnetic losses.展开更多
The cure kinetics of diglycidyl ether of bisphenol A （DGEBA） with hyperbranched poly （3-hydroxyphenyl） phosphate（HHPP） as the curing agent was investigated by means of non-isothermal differential scanning calori...The cure kinetics of diglycidyl ether of bisphenol A （DGEBA） with hyperbranched poly （3-hydroxyphenyl） phosphate（HHPP） as the curing agent was investigated by means of non-isothermal differential scanning calorimetry （DSC） at various heating rates. The results were compared with the corresponding results by using 1,3-dihydroxybenzene（DHB） as a model compound. The results show that HHPP can enhance the cure reaction of DGEBA, resulting in the decrease of the peak temperature of the curing curve as well as the decrease of the activation energy because of the flexible --P--O-- groups in the backbone of HHPP. However, both the activation energy of the cured polymer and the peak temperature of the curing curve are increased with DHB as a curing agent. The cure kinetics of the DGEBA/HHPP system was calculated by using the isoconversional method given by Malek. It was found that the two-parameter autocatalytic model（Sestak-Berggren equation） is the most adequate one to describe the cure kinetics of the studied System at various heating rates. The obtained non-isothermal DSC curves from the experimental data show the results being accordant with those theoretically calculated.展开更多
A series of hyperbranched poly(amine-ester)polyols were synthesized by the polycondensation of N,N-diethylol-3-amine-methylpropionate(prepared by Michael addition reaction of methyl acrylate with diethanolamine)as an ...A series of hyperbranched poly(amine-ester)polyols were synthesized by the polycondensation of N,N-diethylol-3-amine-methylpropionate(prepared by Michael addition reaction of methyl acrylate with diethanolamine)as an AB2-type monomer with trimethylol propane as the core moiety,proceeding in one-step procedure in the melt with p-toluenesulfonic acid as catalyst.The obtained monomer and polymers were characterized by FTIR and 1H-NMR spectroscopy.The solubility and surface activity in aqueous solution of the polymers were also examined.The gas permeability,water vapor permeability,and moisture absorption of microfiber synthetic leather treated by hyperbranched polymer were studied.The optimum conditions were that the dosage of dye and hyperbranched polymer was 5% and 10%,respectively.The water vapor permeability and moisture absorption of microfiber synthetic leather reached to 0.525 4 mg/(10 cm2·24 h)and 0.046 7 mg/(10 cm2·24 h).Compared with blank samples,they increased by 15% and 35%,respectively.However,the dosage of hyperbranched polymer has little influence on gas permeability of microfiber synthetic leather.SEM results show that the fiber of microfiber synthetic leather treated by hyperbranched polymer is incompact.展开更多
A novel liquid hyperbranched polyether epoxy （HBPEE） based on commercially available hydroquinone （HQ） and 1,1,1-trihydroxymethylpropane triglycidyl ether （TMPGE） was synthesized through an A2 ＋ B3 one-step pro...A novel liquid hyperbranched polyether epoxy （HBPEE） based on commercially available hydroquinone （HQ） and 1,1,1-trihydroxymethylpropane triglycidyl ether （TMPGE） was synthesized through an A2 ＋ B3 one-step proton transfer polymerization. In order to improve the toughness, the synthesized HBPEE was mixed with diglycidyl ether of bisphenol A （DGEBA） in different ratios to form hybrids and cured with triethylenetetramine （TETA）. Thermal and mechanical properties of the cured hybrids were evaluated. Results show that addition of HBPEE can improve the toughness of cured hybrids remarkably at 〈 20 wt% loading, without compromising the tensile strength. However, the glass transition temperature （Tg） of the cured hybrids decreases with increasing HBPEE content. Fracture surface images from scanning electron microscope show oriented fibrils in hybrids containing HBPEE. The formation and orientation of the fibrils can absorb energy under impact and lead to an improvement of toughness. Furthermore, based on the morphology of fractured surfaces and the single Tg in each hybrid, no sign of phase separation was found in the cured hybrid systems. As a result, the toughening mechanism could be explained by in situ homogeneous toughening mechanism rather than phase separation mechanism.展开更多
The novel hyperbranced polymers containing reductive groups were successfully prepared and characterized using redox/reversible addition fragmentation chain transfer （RAFT）/self-condensing vinyl polymerization （SCV...The novel hyperbranced polymers containing reductive groups were successfully prepared and characterized using redox/reversible addition fragmentation chain transfer （RAFT）/self-condensing vinyl polymerization （SCVP） method. Several redox initiating chemicals such as Cu（III）/--CONH2, Ce（IV）/--CONH2 and Ce（IV）/--OH were chosen to increase the free radical generating rate, and the chain transfer agent （CTA） was used to reduce the molecular chain propagating rate, in order to obtain polymers with high degree of branching. Detailed analyses based on the molecular weight, α value and the degree of branching of polymers （DB） obtained from 1H-NMR spectra and multi detector size exclusion chromatography （MDSEC） suggested the acquiring of hyperbranced polyacrylamides with Cu（III）/--CONH2 and Ce（IV）/--CONH2 as initiator in the presence of the CTA. Meanwhile, the as-prepared poly（N-hydroxymethyl acrylamide） （PNHAM） with higher DB value （0.48） proved that using Ce（IV）/--OH as the initiator could increase the free radical generating rate and diminish the gap between the propagating rate and the initiation rate during the reaction procedure. In addition, the effect of oxidant concentration on the Mark-Houwink index （α） value and the DB was also studied.展开更多
The monomer 2,6,12-triaminotriptycene was synthesized and the structure was confirmed by IR and 1H NMR spectra. Hyperbranched polyimides modified with different terminal groups were obtained from precursors, anhydride...The monomer 2,6,12-triaminotriptycene was synthesized and the structure was confirmed by IR and 1H NMR spectra. Hyperbranched polyimides modified with different terminal groups were obtained from precursors, anhydride- and aminoterminated hyperbranched poly（amic acid）s from polymerization of A2 ＋ B3 system. From gel permeation chromatograrn （GPC） characterization, representative products had high molecular weight. All polymers had good solubility in CHCl3, DMF and tetrahydrofuran （THF）, and performed no detective Tgs in the range of 50-300 ℃ and high Tds above 455 ℃ when 5% weight loss.展开更多
A novel hyperbranched conjugated chemosensor with bipyridyl groups as periphery groups（BPY-HPV） was synthesized.BPY-HPV was highly sensitive to metal ions（Cu^（2＋）,Ni^（2＋）） for the strong coordination interac...A novel hyperbranched conjugated chemosensor with bipyridyl groups as periphery groups（BPY-HPV） was synthesized.BPY-HPV was highly sensitive to metal ions（Cu^（2＋）,Ni^（2＋）） for the strong coordination interaction（K_（sv） at the order of 10~7 mol^（-1） L） monitored by fluorescence spectroscopy.Moreover,by hydrogen bonds and charge transfer interaction,BPY-HPV shows strong interaction with 1,1,2,2-tetrachloroethane whatever in CH_2Cl_2（K_（sv）～10~6 mol^（-1） L） or film.展开更多
Hyperbranched poly（amine-ester）s bearing self-complementary quadruple hydrogen bonding units display excellent mechanical and temperature-dependent melt rheological properties, which make them suitable as novel hot-...Hyperbranched poly（amine-ester）s bearing self-complementary quadruple hydrogen bonding units display excellent mechanical and temperature-dependent melt rheological properties, which make them suitable as novel hot-melting materials.展开更多
UV-curable hyperbranched polyurethane （UV-HBPU） containing carboxyl groups was synthesized from isophorone diisocyanate （IPDI）, diethanolamine （DEOA）, polyethylene glycol （PEG-400）, hydroxyethyl acrylate （HEA...UV-curable hyperbranched polyurethane （UV-HBPU） containing carboxyl groups was synthesized from isophorone diisocyanate （IPDI）, diethanolamine （DEOA）, polyethylene glycol （PEG-400）, hydroxyethyl acrylate （HEA）, and 2,2-his （hydroxymethyl） propionic acid （DMPA）. The UV-HBPU was used as a negative-type photoresist for a printed circuit board （PCB）. Fourier-transform infrared spectroscopy （FTIR） and proton nuclear magnetic resonance （1HNMR） spectroscopy of UV-HBPUs indicated that the synthesis was successful. Differential scanning calorimetry （DSC） and thermogravimetric analysis （TGA） showed that the thermal stability of the UV-HBPUs decreased as the HEA content increased. The polymer exhibited excellent photoresist properties, and the resolution of circuits based on this negative-type photoresist reached 10 μm.展开更多
Hydrogen production from formic acid decomposition(FAD)is a promising means of hydrogen energy storage and utilization in fuel cells.Development of efficient catalysts for dehydrogenation of formic acid is a challengi...Hydrogen production from formic acid decomposition(FAD)is a promising means of hydrogen energy storage and utilization in fuel cells.Development of efficient catalysts for dehydrogenation of formic acid is a challenging topic.The surface chemical and electronic structure of the active catalysis components is important in formic acid decomposition at room-temperature.Here,the pyrdinic-nitrogen doped catalysts from hyperbranched polyamide were prepared via in situ polymerization reaction process by using activated carbon as a support.Because of the introduction of the polymer,the particles of the catalysts were stabilized,and the average particle diameter was only 1.64 nm.Under mild conditions,the catalysts activities were evaluated for FAD.The optimized Pd-N30/C catalyst exhibited high performance achieving almost full conversion,with a turnover frequency of 3481 h^-1 at 30℃.展开更多
Azide-alkyne click polymerization has become a powerful tool for polymer synthesis.However,the click polymerization between internal alkynes and azides is rarely utilized to prepare functional polymers.In this work,th...Azide-alkyne click polymerization has become a powerful tool for polymer synthesis.However,the click polymerization between internal alkynes and azides is rarely utilized to prepare functional polymers.In this work,the polymerization reactions of activated internal alkyne monomers of tris(2-butynoate)s(1)with tetraphenylethene-containing diazides(2)were performed in dimethylformamide(DMF)under simple heating,affording four hyperbranched poly(methyltriazolylcarboxylate)s(hb-PMTCs)with high molecular weights(A4W up to 2.4 x 104)and regioregularities(up to 83.9%)in good yields.The hb-PMTCs are soluble in common organic solvents,and thermally stable with 5%weight loss temperatures up to 400℃.They are non-emissive in dilute solution,but become highly emissive in aggregated state,exhibiting aggregationinduced emission characteristics.The polymers can generate fluorescent photopatterns with high resolution,and can work as fluorescent sensors to detect nitroaromatic explosive with high sensitivity.展开更多
An NLO hyperbranched polymer(HP1)derived from both"H"-type and star-type chromophores was synthesized successfully for the first time with high yield via one-pot"A2+B3"Suzuki polymerization reactio...An NLO hyperbranched polymer(HP1)derived from both"H"-type and star-type chromophores was synthesized successfully for the first time with high yield via one-pot"A2+B3"Suzuki polymerization reaction.Isolation chromophore was also introduced to further improve its performance.Although under the test conditions,the films of HP1 could not be poled completely,it still demonstrated satisfactory macroscopic NLO effect with the second harmonic generation(SHG)coefficient d33 value of 36 pm/V.展开更多
基金UKRI financial support under grant number EP/Y026098/1 for Global Hydrogen Production Technologies(HyPT)Center。
文摘Anion-exchange membrane water electrolysers(AEMWEs)and fuel cells(AEMFCs)are critical technologies for converting renewable resources into green hydrogen(H_(2)),where anion-exchange membranes(AEMs)play a vital role in efficiently transporting hydroxide ions(OH^(-))and minimizing fuel crossover,thus enhancing overall efficiency.While conventional AEMs with linear,side-chain,and block polymer architectures show promise through functionalization,their long-term performance remains a concern.To address this,hyperbranched polymers offer a promising alternative due to their three-dimensional structure,higher terminal functionality,and ease of functionalization.This unique architecture provides interconnected ion transport pathways,fractional free volume,and enhanced long-term stability in alkaline environments.Recent studies have achieved conductivities as high as 304.5 mS cm^(-1),attributed to their improved fractional free volume and microphase separation in hyperbranched AEMs.This review explores the chemical,mechanical,and ionic properties of hyperbranched AEMs in AEMFCs and assesses their potential for application in AEMWEs.Strategies such as blending and structural functionalisation have significantly improved the properties by promoting microphase separation and increasing the density of cationic groups on the polymer surface.The review provides essential insights for future research,highlighting the challenges and opportunities in developing high-performance hyperbranched AEMs to advance hydrogen energy infrastructure.
基金financially supported by the Scientific Research Start-up Fund Project of Anhui Polytechnic University for Introducing Talents(No.2022YQQ081)Natural Science Research Project of Anhui Educational Committee(No.2024AH050133)the National Natural Science Foundation of China(No.22001078).
文摘Functional hyperbranched polymers,as an important class of materials,are widely applied in diverse areas.Therefore,the development of simple and efficient reactions to prepare hyperbranched polymers is of great significance.In this work,trialdehydes,diamines,and trimethylsilyl cyanide could easily undergo multicomponent polymerization under mild conditions,producing hyperbranched poly(α-aminonitrile)s with high molecular weights(M_(w) up to 4.87×10^(4))in good yields(up to 85%).The hyperbranched poly(α-aminonitrile)s have good solubility in commonly used organic solvents,high thermal stability as well as morphological stability.Furthermore,due to the numerous aldehyde groups in their branched chains,these hb-poly(α-aminonitrile)s can undergo one-pot,two-step,four-component post-polymerization with high efficiency.This work not only confirms the efficiency of our established catalyst-free multicomponent polymerization of aldehydes,amines and trimethylsilyl cyanide,but also provides a versatile and powerful platform for the preparation of functional hyperbranched polymeric materials.
基金The project is supported by the EPSRC and the Youth Science Foundation of Shanghai Higher Education.
文摘An epoxy-terminated hyperbranched aromatic polyester (P3) was synthesized from a hyperbranched aromatic polyester containing carboxylic acid end groups (P1), which was derived from the condensation polymerization of the AB(2) monomer, 5-acetoxyisophthalic acid. Polymer P1 was converted into the polymeric acid chloride by reaction with thionyl chloride. The acid chloride was reacted with ethanol and glycidol to form a poly(ethyl ester) (P2) and an epoxy terminated material (P3), respectively. The reaction conditions in each step of these processes had to be controlled very carefully to avoid unwanted cross-linking reactions. The characterization of products and intermediates, including molecular weight distributions and thermal properties, are reported.
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.
文摘A novel AB3-type monomer was prepared from gallic acid and DL-2-aminobutyric acid, and used for the synthesis of the biocompatible hyperbranched poly(ester-amide)s by self-polycondensation. The polymers were characterized via FTIR and NMR spectroscopy and thermal analysis, and the average degree of branching of the polymers was estimated to be 0.75. The polymers with abundant acetyl end groups were found to be amorphous with lower intrinsic viscosity, better thermal stability and excellent solubility.
文摘UV-curable hyperbranched polyurethane acrylate-polyurethane diacrylate/SiO2 dispersion （HBPUA-PUDA/SiO2） was prepared with isophorone diisocyanate （IPDI）, hyperbranched polyester Boltorn H20 （H20）, hydroxy-ethyl acrylate （HEA）, polyethyleneglycol （PEG-200）and nano-SiO2. The UV curing kinetics of the films was investigated by FTIR. The results show that the curing speed of the films increases with the adding of nano-SiO2 and decreases with the adding of PUDA due to the slower chain movement. The thermal stability of the HBPUA-PUDA/SiO2 films was studied by using thermogravimetric analysis coupled with Fourier transform infrared spectroscopy （TGA/FTIR）. The results show that all films exhibit two degradation stages located at about 320 and 440℃ corresponding to the degradation for hard segments of urethane-acrylate and the degradation for soft segment and polyester core. In addition, the results from the analysis of TGA/FTIR also indicate that the decomposition temperature of HBPUA-PUDA/SiO2 film is 15℃ higher than that obtained for pure polymer. The degradation mechanism was proposed according to TGA/FTIR results.
基金financially supported by the National Natural Science Foundation of China (Nos. 21822102, 21774034, 21490573, 21490574, and 21788102)the Natural Science Foundation of Guangdong Province (Nos. 2016A030306045 and 2016030312002)the Innovation and Technology Commission of Hong Kong (No. ITC-CNERC14SC01)
文摘Hyperbranched polymer with highly branched three-dimensional topological structure, a large number of end groups, and multifaceted functionalities have gained much attention, while polymers with aggregation-induced emission(AIE) properties become a group of popular luminescent materials recently. The design and synthesis of AIE-active hyperbranched polymers, which combine the advantages of these two types of materials, are attractive but challenging. In this work, four hyperbranched poly(tetrahydropyrimidine)s were synthesized from the metal-free room temperature multicomponent tandem polymerization of diester group-activated internal alkyne,polyfunctional aromatic amines, and formaldehyde in methanol under the catalysis of acetic acid. Through different monomer combination and controlling the monomer loading order, hyperbranched polymers with various topological structures as well as sequences of different functional groups in the polymer backbone were obtained with high molecular weights(up to 3.0 × 10~4 g/mol) in high yields(up to 98%). The hyperbranched poly(tetrahydropyrimidine) emitted faintly in solution, while its luminescence was notably enhanced in the aggregated state, suggesting its typical aggregation-induced emission property. It is anticipated that the multicomponent polymerization may provide a synthetic platform for the construction of hyperbranched polyheterocycles with diverse structures and functionalities.
基金This work was partially supported by the Hong Kong Research Grants Council,the University Grants Committee of Hong Kong,and the National Natural Science Foundation of China.
文摘Polycyclotrimerization and polycoupling of acetylenic monomers respectively furnish hyperbranched polyarylenes and polyynes with high molecular weights （up to 1 × 10^6） in high yields （up to 99.9%）. The polymers possess low intrinsic viscosities and high thermal stabilities, losing little of their weights when heated to 〉 400℃. Upon pyrolysis at 〉 800℃, the polymers graphitize with high char yields （up to 86%）. Hyperbranched polyarylenes efficiently emit deep-blue to blue-green lights with fluorescence quantum yields up to 98% and strongly attenuate intense laser pulses with optical power-limiting performances superior to that of C60, a well-known optical limiter. Poly（alkenephenylenes）, poly（aroylarylenes） and polyynes are readily cross-linkable by UV irradiation, serving as excellent photoresist materials for the generation of patterns with nanometer resolution. Thin films of hyperbranched polyynes exhibit very high refractive indexes （n up to 1.86）. The internal and terminal acetylene moieties of the polyynes readily form complexes with cobalt carbonyls, which can be transformed into soft ferromagnetic ceramics with high magnetic susceptibilities （Ms up to ca. 118 emu/g） and near-zero magnetic losses.
文摘The cure kinetics of diglycidyl ether of bisphenol A （DGEBA） with hyperbranched poly （3-hydroxyphenyl） phosphate（HHPP） as the curing agent was investigated by means of non-isothermal differential scanning calorimetry （DSC） at various heating rates. The results were compared with the corresponding results by using 1,3-dihydroxybenzene（DHB） as a model compound. The results show that HHPP can enhance the cure reaction of DGEBA, resulting in the decrease of the peak temperature of the curing curve as well as the decrease of the activation energy because of the flexible --P--O-- groups in the backbone of HHPP. However, both the activation energy of the cured polymer and the peak temperature of the curing curve are increased with DHB as a curing agent. The cure kinetics of the DGEBA/HHPP system was calculated by using the isoconversional method given by Malek. It was found that the two-parameter autocatalytic model（Sestak-Berggren equation） is the most adequate one to describe the cure kinetics of the studied System at various heating rates. The obtained non-isothermal DSC curves from the experimental data show the results being accordant with those theoretically calculated.
基金National High Technology Research and Development Program of China(863program)(No.200803Z309)Optional Item of Shaanxi University of Science and Technology,China(No.ZX08-06)National Natural Science Foundation of China(No.20876090)
文摘A series of hyperbranched poly(amine-ester)polyols were synthesized by the polycondensation of N,N-diethylol-3-amine-methylpropionate(prepared by Michael addition reaction of methyl acrylate with diethanolamine)as an AB2-type monomer with trimethylol propane as the core moiety,proceeding in one-step procedure in the melt with p-toluenesulfonic acid as catalyst.The obtained monomer and polymers were characterized by FTIR and 1H-NMR spectroscopy.The solubility and surface activity in aqueous solution of the polymers were also examined.The gas permeability,water vapor permeability,and moisture absorption of microfiber synthetic leather treated by hyperbranched polymer were studied.The optimum conditions were that the dosage of dye and hyperbranched polymer was 5% and 10%,respectively.The water vapor permeability and moisture absorption of microfiber synthetic leather reached to 0.525 4 mg/(10 cm2·24 h)and 0.046 7 mg/(10 cm2·24 h).Compared with blank samples,they increased by 15% and 35%,respectively.However,the dosage of hyperbranched polymer has little influence on gas permeability of microfiber synthetic leather.SEM results show that the fiber of microfiber synthetic leather treated by hyperbranched polymer is incompact.
基金supported by the Natural Science Foundation of Beijing(No.2092023)National Natural Science Foundation of China(No.51173012)the Fundamental Research Funds for the Central Universities(No.ZZ0912)
文摘A novel liquid hyperbranched polyether epoxy （HBPEE） based on commercially available hydroquinone （HQ） and 1,1,1-trihydroxymethylpropane triglycidyl ether （TMPGE） was synthesized through an A2 ＋ B3 one-step proton transfer polymerization. In order to improve the toughness, the synthesized HBPEE was mixed with diglycidyl ether of bisphenol A （DGEBA） in different ratios to form hybrids and cured with triethylenetetramine （TETA）. Thermal and mechanical properties of the cured hybrids were evaluated. Results show that addition of HBPEE can improve the toughness of cured hybrids remarkably at 〈 20 wt% loading, without compromising the tensile strength. However, the glass transition temperature （Tg） of the cured hybrids decreases with increasing HBPEE content. Fracture surface images from scanning electron microscope show oriented fibrils in hybrids containing HBPEE. The formation and orientation of the fibrils can absorb energy under impact and lead to an improvement of toughness. Furthermore, based on the morphology of fractured surfaces and the single Tg in each hybrid, no sign of phase separation was found in the cured hybrid systems. As a result, the toughening mechanism could be explained by in situ homogeneous toughening mechanism rather than phase separation mechanism.
基金financially supported by the National Natural Science Foundation of China(Nos.20904008 and 21274037)College of Science and Technology Foundation of Hebei Education Department(2010015,B2010000214)
文摘The novel hyperbranced polymers containing reductive groups were successfully prepared and characterized using redox/reversible addition fragmentation chain transfer （RAFT）/self-condensing vinyl polymerization （SCVP） method. Several redox initiating chemicals such as Cu（III）/--CONH2, Ce（IV）/--CONH2 and Ce（IV）/--OH were chosen to increase the free radical generating rate, and the chain transfer agent （CTA） was used to reduce the molecular chain propagating rate, in order to obtain polymers with high degree of branching. Detailed analyses based on the molecular weight, α value and the degree of branching of polymers （DB） obtained from 1H-NMR spectra and multi detector size exclusion chromatography （MDSEC） suggested the acquiring of hyperbranced polyacrylamides with Cu（III）/--CONH2 and Ce（IV）/--CONH2 as initiator in the presence of the CTA. Meanwhile, the as-prepared poly（N-hydroxymethyl acrylamide） （PNHAM） with higher DB value （0.48） proved that using Ce（IV）/--OH as the initiator could increase the free radical generating rate and diminish the gap between the propagating rate and the initiation rate during the reaction procedure. In addition, the effect of oxidant concentration on the Mark-Houwink index （α） value and the DB was also studied.
基金the National Natural Science Foundation(No.50673031)of China and authors would like to extend thanks to Professor Yongming Chen at CAS.
文摘The monomer 2,6,12-triaminotriptycene was synthesized and the structure was confirmed by IR and 1H NMR spectra. Hyperbranched polyimides modified with different terminal groups were obtained from precursors, anhydride- and aminoterminated hyperbranched poly（amic acid）s from polymerization of A2 ＋ B3 system. From gel permeation chromatograrn （GPC） characterization, representative products had high molecular weight. All polymers had good solubility in CHCl3, DMF and tetrahydrofuran （THF）, and performed no detective Tgs in the range of 50-300 ℃ and high Tds above 455 ℃ when 5% weight loss.
基金We are grateful to NSFC(No.20773156)the Ministry of Science and Technology of China(No. 2007AA06A408)the "Bairen program" of CAS,and the Shanghai Science and Technology Committee(Nos. 09XD1405000 and 08JC1421900)
文摘A novel hyperbranched conjugated chemosensor with bipyridyl groups as periphery groups（BPY-HPV） was synthesized.BPY-HPV was highly sensitive to metal ions（Cu^（2＋）,Ni^（2＋）） for the strong coordination interaction（K_（sv） at the order of 10~7 mol^（-1） L） monitored by fluorescence spectroscopy.Moreover,by hydrogen bonds and charge transfer interaction,BPY-HPV shows strong interaction with 1,1,2,2-tetrachloroethane whatever in CH_2Cl_2（K_（sv）～10~6 mol^（-1） L） or film.
基金the National Natural Science Foundation of China (No.20574041)
文摘Hyperbranched poly（amine-ester）s bearing self-complementary quadruple hydrogen bonding units display excellent mechanical and temperature-dependent melt rheological properties, which make them suitable as novel hot-melting materials.
基金Funded by the National Natural Science Foundation of China(Nos.51203063,51103064)
文摘UV-curable hyperbranched polyurethane （UV-HBPU） containing carboxyl groups was synthesized from isophorone diisocyanate （IPDI）, diethanolamine （DEOA）, polyethylene glycol （PEG-400）, hydroxyethyl acrylate （HEA）, and 2,2-his （hydroxymethyl） propionic acid （DMPA）. The UV-HBPU was used as a negative-type photoresist for a printed circuit board （PCB）. Fourier-transform infrared spectroscopy （FTIR） and proton nuclear magnetic resonance （1HNMR） spectroscopy of UV-HBPUs indicated that the synthesis was successful. Differential scanning calorimetry （DSC） and thermogravimetric analysis （TGA） showed that the thermal stability of the UV-HBPUs decreased as the HEA content increased. The polymer exhibited excellent photoresist properties, and the resolution of circuits based on this negative-type photoresist reached 10 μm.
基金supported by the National Natural Science Foundation of China (21633008, 21733004, and 21603216)Jilin Province Science and Technology Development Program (20180101030JC)+2 种基金the Hundred Talents Program of Chinese Academy of Sciencesthe Recruitment Program of Foreign Experts (WQ20122200077)RFBR (18-53-53025)
文摘Hydrogen production from formic acid decomposition(FAD)is a promising means of hydrogen energy storage and utilization in fuel cells.Development of efficient catalysts for dehydrogenation of formic acid is a challenging topic.The surface chemical and electronic structure of the active catalysis components is important in formic acid decomposition at room-temperature.Here,the pyrdinic-nitrogen doped catalysts from hyperbranched polyamide were prepared via in situ polymerization reaction process by using activated carbon as a support.Because of the introduction of the polymer,the particles of the catalysts were stabilized,and the average particle diameter was only 1.64 nm.Under mild conditions,the catalysts activities were evaluated for FAD.The optimized Pd-N30/C catalyst exhibited high performance achieving almost full conversion,with a turnover frequency of 3481 h^-1 at 30℃.
基金the National Natural Science Foundation of China(Nos.21875152 and 21404077)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(No.17KJB150034)+3 种基金the Open Fund of Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates,Guangzhou 510640,China(South China University of Technology)(No.2019B030301003)the Priority Academic Program Development of Jiangsu High Education Institutions(PAPD).M.N.L.and Q.Z.Z.thank the financial support from Undergraduate Training Program for Innovation and Entrepreneurship,Soochow University(No.2018xj032)H.K.L.acknowledges the supports from Jiangsu Planned Projects for Postdoctoral Research Funds(No.1501023B)China Postdoctoral Science Foundation(No.2016M591906).
文摘Azide-alkyne click polymerization has become a powerful tool for polymer synthesis.However,the click polymerization between internal alkynes and azides is rarely utilized to prepare functional polymers.In this work,the polymerization reactions of activated internal alkyne monomers of tris(2-butynoate)s(1)with tetraphenylethene-containing diazides(2)were performed in dimethylformamide(DMF)under simple heating,affording four hyperbranched poly(methyltriazolylcarboxylate)s(hb-PMTCs)with high molecular weights(A4W up to 2.4 x 104)and regioregularities(up to 83.9%)in good yields.The hb-PMTCs are soluble in common organic solvents,and thermally stable with 5%weight loss temperatures up to 400℃.They are non-emissive in dilute solution,but become highly emissive in aggregated state,exhibiting aggregationinduced emission characteristics.The polymers can generate fluorescent photopatterns with high resolution,and can work as fluorescent sensors to detect nitroaromatic explosive with high sensitivity.
基金supported by the National Natural Science Foundation of China(No.21034006)
文摘An NLO hyperbranched polymer(HP1)derived from both"H"-type and star-type chromophores was synthesized successfully for the first time with high yield via one-pot"A2+B3"Suzuki polymerization reaction.Isolation chromophore was also introduced to further improve its performance.Although under the test conditions,the films of HP1 could not be poled completely,it still demonstrated satisfactory macroscopic NLO effect with the second harmonic generation(SHG)coefficient d33 value of 36 pm/V.
