A new blend of poly(2-hydroxyethyl methacrylate) (PHEMA) with poly (ethylene glycol) (PEG) was prepared. The results from solid-state NMR indicate that the PHEMA/PEG(88:12, w/w) blend is miscible on a molecular level.
Thermo-responsive random copolymers,poly(2-(2-methoxyethoxy)ethoxyethyl methacrylate-co-(ethylene glycol)methyl ether methacrylate)(P(EO_(2)-co-EO_(4/5)))and poly(2-(2-methoxyethoxy)ethoxyethyl methacrylate-co-ethylen...Thermo-responsive random copolymers,poly(2-(2-methoxyethoxy)ethoxyethyl methacrylate-co-(ethylene glycol)methyl ether methacrylate)(P(EO_(2)-co-EO_(4/5)))and poly(2-(2-methoxyethoxy)ethoxyethyl methacrylate-co-ethylene glycol methacrylate(P(EO2-co-EG4/5))are synthesized via atom transfer radical polymerization(ATRP).The successful synthesis and the narrow polydispersity index(PDI)of two copolymers are indicated by 1H nuclear magnetic resonance(1H-NMR)and gel permeation chromatography(GPC)analyses.The transition behaviors of polymers in the aqueous solution are demonstrated by changes in turbidity and particle sizes.The transition behavior of P(EO2-co-EG4/5)is found to be milder than that of P(EO2-co-EO4/5).Moreover,the presence of hydrogen bonds without thermo-responsive properties established by hydroxyl groups in the end-side chain of P(EO_(2)-co-EG_(4/5))hinders the dehydration at the transition temperature(TT).Attenuated total reflection Fourier transform infrared spectrometry(ATR-FTIR)analysis along with contact angle measurements reveals that both P(EO_(2)-co-EO_(4/5))and P(EO_(2)-co-EG_(4/5))films undergo phase transitions from hydrophilicity to hydrophobicity above TT.By examining the swelling and collapse behaviors of the polymer films during phase transitions,it can be concluded that the end hydroxyl groups may establish hydrogen bonds with neighboring ether groups within the films,which remain intact throughout the phase transition process due to their strong bonding interactions.This leads to an increase in steric hindrance within swollen films thereby impeding dehydration processes and inducing hysteresis during phase transitions.展开更多
Well-defined nonionic hydrophilic ω-acryloyl poly(ethylene oxide) macro-monomer (PEO-A) has been prepared by living anionic polymerization of ethylene oxidewith diphenyl methyl potassium as the initiator and acryloyl...Well-defined nonionic hydrophilic ω-acryloyl poly(ethylene oxide) macro-monomer (PEO-A) has been prepared by living anionic polymerization of ethylene oxidewith diphenyl methyl potassium as the initiator and acryloyl chloride as the reaction termi-nating agent. The polymer was characterized by FTIR and SEC. The emulsifier-free emul-sion polymerization of methyl methacrylate (MMA) and n-butyl acrylate (BA) containingvarious concentrations of PEO-A was studied. In all cases stable emulsion coplymerizationsof MMA and BA were obtained. The stabilizing effect was found to be dependent on themolecular weight and the feed amount of the macromonomer.展开更多
The monodisperse poly(glycidyl methacrylate-co-ethylene dimethacrylate) beads with macroporous in the range of 8.0—12.0 m were prepared by a single-step swelling and polymerization method. The seed particles prepared...The monodisperse poly(glycidyl methacrylate-co-ethylene dimethacrylate) beads with macroporous in the range of 8.0—12.0 m were prepared by a single-step swelling and polymerization method. The seed particles prepared by dispersion polymerization exhibited good absorption of the monomer phase. The pore size distribution of the beads was evaluated by gel permeation chromatography and mercury intrusion method. By using this media, a weak cation exchange (WCX) stationary phase for HPLC was synthesized by a new chemical modification method. The prepared resin has advantages of biopolymer separation, high column efficiency, low column backpressure, high protein mass recovery and good resolution for proteins. The measured bioactivity recovery for lysozyme was (96±5)%. The dynamic protein loading capacity of the synthesized WCX packings was 21.3 mg/g. Five proteins were completely separated in 8.0 min using the synthesized WCX stationary phase. The experimental results show that the obtained WCX resin has very weak hydrophobicity. The WCX resin was also used for the rapid separation and purification of lysozyme from egg white in 8 min with only one step . The purity and specific bioactivity of the purified lysozyme was found more than 92.0% and 70184 U/mg, respectively.展开更多
A universally significant method,which combines the anionic polymerization with photoinduced charge transfer polymerization,for preparation of soluble star ABC triblock copolymer of ethylene oxide,styrene and methyl m...A universally significant method,which combines the anionic polymerization with photoinduced charge transfer polymerization,for preparation of soluble star ABC triblock copolymer of ethylene oxide,styrene and methyl methacrylate,was described.The poly(ethylene oxide) (PEO) block was formed by initiation of phenoxy an-ions using p-aminophenol protected by Schiff’s base as the parent compound Then the charge transfer system composed of PEO chains with deprotected-amino end groups and benzophenone initiated the polymerization of styrene and methyl metnacrylate sequentially under UV irradiation.The formed star triblock copolymer of styrene,ethylene oxide and methyl methacrylate could be purified by thin-layer chromatography (TLC) and characterized by IR,1H NMR,GPC (gel permeation chromatogrphy) and PGC (pyrolysis gas chromatography).展开更多
Novel thermo-responsive cellulose papers were prepared via grafting poly(di(ethylene glycol)methyl ether methacrylate)(PDEGMA)by activators regenerating electron transfer(ARGET)and atom transfer radical polymerization...Novel thermo-responsive cellulose papers were prepared via grafting poly(di(ethylene glycol)methyl ether methacrylate)(PDEGMA)by activators regenerating electron transfer(ARGET)and atom transfer radical polymerization(ATRP).Attenuated total refraction Fourier-transform infrared spectroscopy(ATR-FTIR)and scanning electron microscopy(SEM)measurements of the modified paper showed that PDEGMA brushes were successfully grafted on the paper surface.The thermal stability of the papers before and after grafting was evaluated by thermogravimetric analysis(TGA).The PDEGMA-grafted paper exhibited a two-step thermal degradation process,and presented thermo-responsive characteristics.It was hydrophilic at room temperature but changed rapidly to highly hydrophobic when the temperature rose above 50℃.展开更多
文摘A new blend of poly(2-hydroxyethyl methacrylate) (PHEMA) with poly (ethylene glycol) (PEG) was prepared. The results from solid-state NMR indicate that the PHEMA/PEG(88:12, w/w) blend is miscible on a molecular level.
基金Fujian External Cooperation project of Natural Science Foundation,China(No.2022I0042)。
文摘Thermo-responsive random copolymers,poly(2-(2-methoxyethoxy)ethoxyethyl methacrylate-co-(ethylene glycol)methyl ether methacrylate)(P(EO_(2)-co-EO_(4/5)))and poly(2-(2-methoxyethoxy)ethoxyethyl methacrylate-co-ethylene glycol methacrylate(P(EO2-co-EG4/5))are synthesized via atom transfer radical polymerization(ATRP).The successful synthesis and the narrow polydispersity index(PDI)of two copolymers are indicated by 1H nuclear magnetic resonance(1H-NMR)and gel permeation chromatography(GPC)analyses.The transition behaviors of polymers in the aqueous solution are demonstrated by changes in turbidity and particle sizes.The transition behavior of P(EO2-co-EG4/5)is found to be milder than that of P(EO2-co-EO4/5).Moreover,the presence of hydrogen bonds without thermo-responsive properties established by hydroxyl groups in the end-side chain of P(EO_(2)-co-EG_(4/5))hinders the dehydration at the transition temperature(TT).Attenuated total reflection Fourier transform infrared spectrometry(ATR-FTIR)analysis along with contact angle measurements reveals that both P(EO_(2)-co-EO_(4/5))and P(EO_(2)-co-EG_(4/5))films undergo phase transitions from hydrophilicity to hydrophobicity above TT.By examining the swelling and collapse behaviors of the polymer films during phase transitions,it can be concluded that the end hydroxyl groups may establish hydrogen bonds with neighboring ether groups within the films,which remain intact throughout the phase transition process due to their strong bonding interactions.This leads to an increase in steric hindrance within swollen films thereby impeding dehydration processes and inducing hysteresis during phase transitions.
文摘Well-defined nonionic hydrophilic ω-acryloyl poly(ethylene oxide) macro-monomer (PEO-A) has been prepared by living anionic polymerization of ethylene oxidewith diphenyl methyl potassium as the initiator and acryloyl chloride as the reaction termi-nating agent. The polymer was characterized by FTIR and SEC. The emulsifier-free emul-sion polymerization of methyl methacrylate (MMA) and n-butyl acrylate (BA) containingvarious concentrations of PEO-A was studied. In all cases stable emulsion coplymerizationsof MMA and BA were obtained. The stabilizing effect was found to be dependent on themolecular weight and the feed amount of the macromonomer.
基金Project supported by the National Natural Science Foundation of China (Nos. 39880003 and 20175016 ).
文摘The monodisperse poly(glycidyl methacrylate-co-ethylene dimethacrylate) beads with macroporous in the range of 8.0—12.0 m were prepared by a single-step swelling and polymerization method. The seed particles prepared by dispersion polymerization exhibited good absorption of the monomer phase. The pore size distribution of the beads was evaluated by gel permeation chromatography and mercury intrusion method. By using this media, a weak cation exchange (WCX) stationary phase for HPLC was synthesized by a new chemical modification method. The prepared resin has advantages of biopolymer separation, high column efficiency, low column backpressure, high protein mass recovery and good resolution for proteins. The measured bioactivity recovery for lysozyme was (96±5)%. The dynamic protein loading capacity of the synthesized WCX packings was 21.3 mg/g. Five proteins were completely separated in 8.0 min using the synthesized WCX stationary phase. The experimental results show that the obtained WCX resin has very weak hydrophobicity. The WCX resin was also used for the rapid separation and purification of lysozyme from egg white in 8 min with only one step . The purity and specific bioactivity of the purified lysozyme was found more than 92.0% and 70184 U/mg, respectively.
基金Project supported by the National Natural Science Foundation of Chinathe Doctoral Training Foundation of the State Education Commission of China
文摘A universally significant method,which combines the anionic polymerization with photoinduced charge transfer polymerization,for preparation of soluble star ABC triblock copolymer of ethylene oxide,styrene and methyl methacrylate,was described.The poly(ethylene oxide) (PEO) block was formed by initiation of phenoxy an-ions using p-aminophenol protected by Schiff’s base as the parent compound Then the charge transfer system composed of PEO chains with deprotected-amino end groups and benzophenone initiated the polymerization of styrene and methyl metnacrylate sequentially under UV irradiation.The formed star triblock copolymer of styrene,ethylene oxide and methyl methacrylate could be purified by thin-layer chromatography (TLC) and characterized by IR,1H NMR,GPC (gel permeation chromatogrphy) and PGC (pyrolysis gas chromatography).
基金supported by the National Natural Science Foundation of China (No.31200453,31200454)the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD).
文摘Novel thermo-responsive cellulose papers were prepared via grafting poly(di(ethylene glycol)methyl ether methacrylate)(PDEGMA)by activators regenerating electron transfer(ARGET)and atom transfer radical polymerization(ATRP).Attenuated total refraction Fourier-transform infrared spectroscopy(ATR-FTIR)and scanning electron microscopy(SEM)measurements of the modified paper showed that PDEGMA brushes were successfully grafted on the paper surface.The thermal stability of the papers before and after grafting was evaluated by thermogravimetric analysis(TGA).The PDEGMA-grafted paper exhibited a two-step thermal degradation process,and presented thermo-responsive characteristics.It was hydrophilic at room temperature but changed rapidly to highly hydrophobic when the temperature rose above 50℃.
