Acryloyl terminated Poly (ethyleneoxide)macromonomers (PEO-A) with different PEO chain lengths have been prepared by deactivation of PEO alkoxide with acryloyl chloride. A new kind of amphiphilic polystyrene-g-poly (e...Acryloyl terminated Poly (ethyleneoxide)macromonomers (PEO-A) with different PEO chain lengths have been prepared by deactivation of PEO alkoxide with acryloyl chloride. A new kind of amphiphilic polystyrene-g-poly (ethylene oxide)graft copolymer containing both microphase separated and PEO side chain structures has been synthesized from radical copolymerization of PEO-A macromonomer with styrene. After careful purification by a newly-developed method called 'selective dissolution', the well-defined structure of the purified copolymers was confirmed by IR, ~1H-NMR and GPC. Various experimental parameters controlling the copolymerization were studied in detail. The results indicated that the feed ratio of styrene to macromonomer(S/M) was the most important determining factor for the composition of the copolymers. A detailed 'comb- model' was proposed to describe the molecular structure of the graft copolymers. Finally, this amphiphilic graft copolymers may readily form microphase separated structures as clearly indicated by transmission electron microscopy.展开更多
The present paper covers the poly (ethylene oxide) macromer with vinyl benzyl terminal group (PEO-VB) prepared by deactivation of the alkoxide function of mono-functional 'living' PEO chains with vinyl benzyl ...The present paper covers the poly (ethylene oxide) macromer with vinyl benzyl terminal group (PEO-VB) prepared by deactivation of the alkoxide function of mono-functional 'living' PEO chains with vinyl benzyl chloride (VBC). The obtained macromers were subjected to careful purification and detailed characterization. A new kind of amphiphilic polystyrene-g-poly(ethylene oxide) (PS-g-PEO) with both mi-crophase separated and PEO side chains was synthesized from radical copolymerization of PEO-VB macromer with styrene monomer. An improved purification method, referred as 'selective dissolvation', was established for the isolation of graft copolymers from the grafting products, and the purity and yield of the purified copolymers were satisfactory. The well-defined structure of the purified copolymers was confirmed by IR, 1H NMR and GPC. The bulk composition of the graft copolymers was determined by a well-established first derivative UV spectrometry. Various experimental parameters controlling the copolymerization were also studied. The results indicate that the feed ratio of macromer to styrene (M/S) was the most important factor in determining the composition of the copolymers. Thus a series of PS-g-PEO with a wide range of bulk compositions were obtained simply by adjusting the value of M/S. As clearly indicated by transmission electron microscopy, this amphiphilic graft copolymers may readily form microphase separated structures.展开更多
A ternary hybrid membrane architecture consisting of sulfonated fluorinated multi-block copolymer （SFMC）, sulfonated （poly ether ether ketone） （SPEEK） and I or 5 wt% graphene oxide （GO） was fabricated through ...A ternary hybrid membrane architecture consisting of sulfonated fluorinated multi-block copolymer （SFMC）, sulfonated （poly ether ether ketone） （SPEEK） and I or 5 wt% graphene oxide （GO） was fabricated through a facile solution casting approach. The simple, but effective monomer sulfonation was performed for SFMC to create compact and rigid hydrophobic backbone structures, while conventional random sulfonation was carried-out for SPEEK. Hydrophilic-hydrophobic-hydrophilic structure of SFMC enhances the compatibility with SPEEK and GO and allows for an unprecedented approach to alter me- chanical strength and proton conductivity of ternary hybrid membrane, as verified from universal test machine （UTM） curves and alternating current （AC） impedance plots. The impact of GO integration on the morphology and roughness of hybrid membrane was scrutinized using field emission scanning electron microscope （FE-SEM） and atomic force microscope （AFM）. Ternary hybrid showed uniform intercalation of GO nanosheets throughout the entire surface of membrane with an increased surface roughness of 8.91 nm. The constructed ternary hybrid membrane revealed excellent water absorption, ion exchange capacity and gas barrier properties, while retaining reasonable dimensional stability. The well-optimized ternary hybrid membrane containing 5 wt% GO revealed a maximum proton conductivity of 111.9 mS/cm, which is higher by a factor of two-fold with respect to that of bare SFMC membrane. The maximum PEMFC power density of 528.07mW/cm2 was yielded by ternary hybrid membrane at a load current density of 1321.1 mA/cm2 when operating the cell at 70 ℃ under 100% relative humidity （RH）. In comparison, a maximum power density of only 182.06 mW/cm2 was exhibited by the bare SFMC membrane at a load current density of 455.56 mA/cm2 under same operating conditions.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
This paper reported the research results concerning the surface characterization ofpolystyrene-graft-w-stearyl poly(ethylene oxide) (PS-g-SPEO) by means of XPS,contactangle measurement and TEM, and its in vitro blood ...This paper reported the research results concerning the surface characterization ofpolystyrene-graft-w-stearyl poly(ethylene oxide) (PS-g-SPEO) by means of XPS,contactangle measurement and TEM, and its in vitro blood compatibility assessment by measuringthe plasma recalcification time (RT) and partial thromboplastin time (PTT). The XPSresults demonstrated that the surface and bulk composition of the PS-g-SPEO graftcopolymers differ remarkably from each other,and that SPEO component was constantlyenriched at the copolymer/air interface. Contact angle studies indicated that the surfacewater wettability can be adjusted effectively by changing the composition of the copolymer.PS-g-SPEO graft copolymers can undergo microphase separation as clearly illustrated byTEM photographs. The relationship between the surface properties of PS-g-SPEO graftcopolymer and its blood compatibility was also discussed.展开更多
In this paper,a amphiphilic brush copolymer poly(propylene oxide)-graft-poly(N,N-dimethylaminoethyl methacrylate)(PPO-gPDMAEMA)was successfully prepared via the combine of anionic ring opening polymerization and atom ...In this paper,a amphiphilic brush copolymer poly(propylene oxide)-graft-poly(N,N-dimethylaminoethyl methacrylate)(PPO-gPDMAEMA)was successfully prepared via the combine of anionic ring opening polymerization and atom transfer radical polymerization(ATRP).The target products were confirmed by GPC and1H NMR.This well-defined copolymer can supply a promising material as drug and gene carriers and protective materials.展开更多
This paper describes the synthesis, surface tension and dispersancy properties of block copolymer nonionic surfactants comprised of polyethyleneimine (PEI) and polyethylene oxide (PEO) blocks of selected lengths. Thes...This paper describes the synthesis, surface tension and dispersancy properties of block copolymer nonionic surfactants comprised of polyethyleneimine (PEI) and polyethylene oxide (PEO) blocks of selected lengths. These block copolymers were prepared by a three step synthetic sequence. Firstly, PEO glycol was converted to its dimethanesulphonylester (dimesyl) derivative by reacting with methanesulphonyl chloride. Then a tri block polymer was prepared by the ring opening polymerization of 2 methyl 2 oxazoline (MeOZO) with the dimesyl PEO derivative. Lastly, linear PEI blocks were obtained by subsequent hydrolysis and purification. 1H NMR spectra confirmed the structures of the intermediate, final products and their purities (>99%). The utility of these block copolymers is described in terms of their surface tension and clay dispersancy measurements as a function of copolymer chain and block length.展开更多
A new series of high molecular weight amphi-philic graft copolymers PE-g-PEO has been prepared. The esterifications between PE-p-MS-g-MA and PEO with OH group at the chain end are carried out under different condi-tio...A new series of high molecular weight amphi-philic graft copolymers PE-g-PEO has been prepared. The esterifications between PE-p-MS-g-MA and PEO with OH group at the chain end are carried out under different condi-tions. The compositions of these graft copolymers are studied by NMR and FTIR. It is found to be a convenient and effi-cient way to prepare high molecular weight PE-g-PEO graft copolymers.展开更多
A new route for synthesis of amphiphilic graft copolymer PE-gPEO containing hydrophobic polyethylene as the backbone and hydrophilic poly(ethylene oxide) a s the side chain has been discussed in this paper.The structu...A new route for synthesis of amphiphilic graft copolymer PE-gPEO containing hydrophobic polyethylene as the backbone and hydrophilic poly(ethylene oxide) a s the side chain has been discussed in this paper.The structure of the copolyme r(such as graft density and graft length),the molecular weights of both polyeth ylene and poly(ethylene oxide) side chain,as well as the molecular weight distr ibution of the copolymer can be designed and controlled easily by this route.Th e molecular weight of poly(ethylene oxide) side chain is proportional to the pol ymerization reaction time and the ethylene oxide monomer concentration,which in dicates the “living" characterization of the anonic polymerization of ethylene oxide.The graft copolymers PE-g-PEO synthesized have been characterized b y 1H-NMR and DSC tests.And the SEM result shows that after adding the amp hiphili c graft copolymer PE-g-PEO as the compatibilizer for the PE/PC polymeric b lend,the compatibility of the blend improved greatly.Therefore,this kind of a mphiphilic graft copolymers can be used as the efficient surfactant for the poly olefin blend and composite materials.展开更多
The solution property of amphiphilic graft copolymer has been examined by means of NMR,TEM and viscometry. It is found that water and toluene are selective solvent for PSt- g- PEO. When it is dissolved in water, micel...The solution property of amphiphilic graft copolymer has been examined by means of NMR,TEM and viscometry. It is found that water and toluene are selective solvent for PSt- g- PEO. When it is dissolved in water, micelle can be formed with hydrophobic PSt backbone as the core and hydrophilic PEO side chains as the shell. On the other hand, in selective solvent toluene, the reversed- micelle can be formed with PEO as core and PSt as the shell. In toluene, with an increase in concentration, the conformation of PSt- g- PEO can be transformed from stretched single molecule to spherical reversed- micelle. The critical micelle concentration(CMC) is determined at different temperature and with the increase of temperature and the content of PEO the reversed- micelle can be formed in lower concentrations.展开更多
The biodegradation behavior in vitro and in vivo of polycaprolactone poly (ethylene oxide) block copolymers ( P C E) has been reported in detail. Photodegradation testof P C E was performed by exposure to U Vlight. Th...The biodegradation behavior in vitro and in vivo of polycaprolactone poly (ethylene oxide) block copolymers ( P C E) has been reported in detail. Photodegradation testof P C E was performed by exposure to U Vlight. The mechanical properties and the inherentviscosity of P C Esamples which are subjected to photodegradation were determined . Thephotodegradation rate of P C E was much more faster than its hydrolysis rate and wasincreased with increasing poly(ethylene oxide) content. The experimental results alsoindicated that the pure poly(ethylene oxide) ( P E O) can not be photodegraded alone. Amechanism forthe photodegradation of P C Ecopolymers was proposed :thecarbonylgroupsin P C Lsegmentscatalyze the breakage ofthe P E Ochains by a seriesof U Vinitiated freeradicalreactions. When the free radicals induce the degradation of P E O segments in P C E,thephotodegradation of P C E mainly occursin P E Osegments.展开更多
基金Supported by the National Natural Science Foundation of China and the State Education Committee of China
文摘Acryloyl terminated Poly (ethyleneoxide)macromonomers (PEO-A) with different PEO chain lengths have been prepared by deactivation of PEO alkoxide with acryloyl chloride. A new kind of amphiphilic polystyrene-g-poly (ethylene oxide)graft copolymer containing both microphase separated and PEO side chain structures has been synthesized from radical copolymerization of PEO-A macromonomer with styrene. After careful purification by a newly-developed method called 'selective dissolution', the well-defined structure of the purified copolymers was confirmed by IR, ~1H-NMR and GPC. Various experimental parameters controlling the copolymerization were studied in detail. The results indicated that the feed ratio of styrene to macromonomer(S/M) was the most important determining factor for the composition of the copolymers. A detailed 'comb- model' was proposed to describe the molecular structure of the graft copolymers. Finally, this amphiphilic graft copolymers may readily form microphase separated structures as clearly indicated by transmission electron microscopy.
基金Supported by the National Natural Science Foundation of China The State Education Commission of China
文摘The present paper covers the poly (ethylene oxide) macromer with vinyl benzyl terminal group (PEO-VB) prepared by deactivation of the alkoxide function of mono-functional 'living' PEO chains with vinyl benzyl chloride (VBC). The obtained macromers were subjected to careful purification and detailed characterization. A new kind of amphiphilic polystyrene-g-poly(ethylene oxide) (PS-g-PEO) with both mi-crophase separated and PEO side chains was synthesized from radical copolymerization of PEO-VB macromer with styrene monomer. An improved purification method, referred as 'selective dissolvation', was established for the isolation of graft copolymers from the grafting products, and the purity and yield of the purified copolymers were satisfactory. The well-defined structure of the purified copolymers was confirmed by IR, 1H NMR and GPC. The bulk composition of the graft copolymers was determined by a well-established first derivative UV spectrometry. Various experimental parameters controlling the copolymerization were also studied. The results indicate that the feed ratio of macromer to styrene (M/S) was the most important factor in determining the composition of the copolymers. Thus a series of PS-g-PEO with a wide range of bulk compositions were obtained simply by adjusting the value of M/S. As clearly indicated by transmission electron microscopy, this amphiphilic graft copolymers may readily form microphase separated structures.
基金supported by the Korea Institute of Energy Technology Evaluation and Planning(KETEP)the Ministry of Trade,Industry&Energy(MOTIE)of the Republic of Korea(No.20164030201070)supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science,ICT and future Planning(NRF-2017R1A2B4005230)
文摘A ternary hybrid membrane architecture consisting of sulfonated fluorinated multi-block copolymer （SFMC）, sulfonated （poly ether ether ketone） （SPEEK） and I or 5 wt% graphene oxide （GO） was fabricated through a facile solution casting approach. The simple, but effective monomer sulfonation was performed for SFMC to create compact and rigid hydrophobic backbone structures, while conventional random sulfonation was carried-out for SPEEK. Hydrophilic-hydrophobic-hydrophilic structure of SFMC enhances the compatibility with SPEEK and GO and allows for an unprecedented approach to alter me- chanical strength and proton conductivity of ternary hybrid membrane, as verified from universal test machine （UTM） curves and alternating current （AC） impedance plots. The impact of GO integration on the morphology and roughness of hybrid membrane was scrutinized using field emission scanning electron microscope （FE-SEM） and atomic force microscope （AFM）. Ternary hybrid showed uniform intercalation of GO nanosheets throughout the entire surface of membrane with an increased surface roughness of 8.91 nm. The constructed ternary hybrid membrane revealed excellent water absorption, ion exchange capacity and gas barrier properties, while retaining reasonable dimensional stability. The well-optimized ternary hybrid membrane containing 5 wt% GO revealed a maximum proton conductivity of 111.9 mS/cm, which is higher by a factor of two-fold with respect to that of bare SFMC membrane. The maximum PEMFC power density of 528.07mW/cm2 was yielded by ternary hybrid membrane at a load current density of 1321.1 mA/cm2 when operating the cell at 70 ℃ under 100% relative humidity （RH）. In comparison, a maximum power density of only 182.06 mW/cm2 was exhibited by the bare SFMC membrane at a load current density of 455.56 mA/cm2 under same operating conditions.
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This work was supported by the National Natural Science Foundation of China and the State Education Committee of China.
文摘This paper reported the research results concerning the surface characterization ofpolystyrene-graft-w-stearyl poly(ethylene oxide) (PS-g-SPEO) by means of XPS,contactangle measurement and TEM, and its in vitro blood compatibility assessment by measuringthe plasma recalcification time (RT) and partial thromboplastin time (PTT). The XPSresults demonstrated that the surface and bulk composition of the PS-g-SPEO graftcopolymers differ remarkably from each other,and that SPEO component was constantlyenriched at the copolymer/air interface. Contact angle studies indicated that the surfacewater wettability can be adjusted effectively by changing the composition of the copolymer.PS-g-SPEO graft copolymers can undergo microphase separation as clearly illustrated byTEM photographs. The relationship between the surface properties of PS-g-SPEO graftcopolymer and its blood compatibility was also discussed.
文摘In this paper,a amphiphilic brush copolymer poly(propylene oxide)-graft-poly(N,N-dimethylaminoethyl methacrylate)(PPO-gPDMAEMA)was successfully prepared via the combine of anionic ring opening polymerization and atom transfer radical polymerization(ATRP).The target products were confirmed by GPC and1H NMR.This well-defined copolymer can supply a promising material as drug and gene carriers and protective materials.
文摘This paper describes the synthesis, surface tension and dispersancy properties of block copolymer nonionic surfactants comprised of polyethyleneimine (PEI) and polyethylene oxide (PEO) blocks of selected lengths. These block copolymers were prepared by a three step synthetic sequence. Firstly, PEO glycol was converted to its dimethanesulphonylester (dimesyl) derivative by reacting with methanesulphonyl chloride. Then a tri block polymer was prepared by the ring opening polymerization of 2 methyl 2 oxazoline (MeOZO) with the dimesyl PEO derivative. Lastly, linear PEI blocks were obtained by subsequent hydrolysis and purification. 1H NMR spectra confirmed the structures of the intermediate, final products and their purities (>99%). The utility of these block copolymers is described in terms of their surface tension and clay dispersancy measurements as a function of copolymer chain and block length.
文摘A new series of high molecular weight amphi-philic graft copolymers PE-g-PEO has been prepared. The esterifications between PE-p-MS-g-MA and PEO with OH group at the chain end are carried out under different condi-tions. The compositions of these graft copolymers are studied by NMR and FTIR. It is found to be a convenient and effi-cient way to prepare high molecular weight PE-g-PEO graft copolymers.
文摘A new route for synthesis of amphiphilic graft copolymer PE-gPEO containing hydrophobic polyethylene as the backbone and hydrophilic poly(ethylene oxide) a s the side chain has been discussed in this paper.The structure of the copolyme r(such as graft density and graft length),the molecular weights of both polyeth ylene and poly(ethylene oxide) side chain,as well as the molecular weight distr ibution of the copolymer can be designed and controlled easily by this route.Th e molecular weight of poly(ethylene oxide) side chain is proportional to the pol ymerization reaction time and the ethylene oxide monomer concentration,which in dicates the “living" characterization of the anonic polymerization of ethylene oxide.The graft copolymers PE-g-PEO synthesized have been characterized b y 1H-NMR and DSC tests.And the SEM result shows that after adding the amp hiphili c graft copolymer PE-g-PEO as the compatibilizer for the PE/PC polymeric b lend,the compatibility of the blend improved greatly.Therefore,this kind of a mphiphilic graft copolymers can be used as the efficient surfactant for the poly olefin blend and composite materials.
文摘The solution property of amphiphilic graft copolymer has been examined by means of NMR,TEM and viscometry. It is found that water and toluene are selective solvent for PSt- g- PEO. When it is dissolved in water, micelle can be formed with hydrophobic PSt backbone as the core and hydrophilic PEO side chains as the shell. On the other hand, in selective solvent toluene, the reversed- micelle can be formed with PEO as core and PSt as the shell. In toluene, with an increase in concentration, the conformation of PSt- g- PEO can be transformed from stretched single molecule to spherical reversed- micelle. The critical micelle concentration(CMC) is determined at different temperature and with the increase of temperature and the content of PEO the reversed- micelle can be formed in lower concentrations.
文摘The biodegradation behavior in vitro and in vivo of polycaprolactone poly (ethylene oxide) block copolymers ( P C E) has been reported in detail. Photodegradation testof P C E was performed by exposure to U Vlight. The mechanical properties and the inherentviscosity of P C Esamples which are subjected to photodegradation were determined . Thephotodegradation rate of P C E was much more faster than its hydrolysis rate and wasincreased with increasing poly(ethylene oxide) content. The experimental results alsoindicated that the pure poly(ethylene oxide) ( P E O) can not be photodegraded alone. Amechanism forthe photodegradation of P C Ecopolymers was proposed :thecarbonylgroupsin P C Lsegmentscatalyze the breakage ofthe P E Ochains by a seriesof U Vinitiated freeradicalreactions. When the free radicals induce the degradation of P E O segments in P C E,thephotodegradation of P C E mainly occursin P E Osegments.
