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 thermally stimulated shape memory behavior of ethylene oxide-butylene terephthalate (EOBT) segmented copolymers with different soft segment molecular weight and hard segment content was investigated. The deformati...The thermally stimulated shape memory behavior of ethylene oxide-butylene terephthalate (EOBT) segmented copolymers with different soft segment molecular weight and hard segment content was investigated. The deformation recovery ratio R-f of the EOBT samples increases with the soft segment molecular weight and the hard segment weight content, while the average overall deformation recovery speed V-r increases with the hard segment content. The temperature of maximum deformation recovery speed (T-M) is determined by the melting temperature of the soft segment crystals and the stability of the crystallized hard segment domains.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
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
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
A series of ethylene oxide-ethylene terephthalate segmented copolymers (EOET) weresynthesized and complexed with LiClO_4 to form some new polymer electrolytes. The EOET-LiClO_4 electrolytes exhibit not only high ionic...A series of ethylene oxide-ethylene terephthalate segmented copolymers (EOET) weresynthesized and complexed with LiClO_4 to form some new polymer electrolytes. The EOET-LiClO_4 electrolytes exhibit not only high ionic conductivity, but also good mechanical strengthand toughness. The EOET 3400--25--LiClO_4 complex possesses the highest conductivity (4. 65×10^(-5)s·cm^(-1) at room temperature when the ratio [Li^+]/[EO] equals 1/16. The structures of these electrolytes were examined with FTIR analysis, X-ray diffractionand DSC thermograms, and the results of high ionic conductivity of the segmented copolymerswere discussed.展开更多
A series of ethylene oxide-butylene terephthalate (EOBT) segmented copolymers with different soft segment length and hard segment content were synthesized. The compositional heterogeneity was studied by solvent extrac...A series of ethylene oxide-butylene terephthalate (EOBT) segmented copolymers with different soft segment length and hard segment content were synthesized. The compositional heterogeneity was studied by solvent extraction. The results show that the compositional heterogeneity increases when soft segment length and hard segment content increase. The compositional heterogeneity is also reflected in the crystallization behavior and morphology of soft and hard segment in EOBT segmented copolymer. The more compositional heterogeneous the EOBT segmented copolymer is, the more different the morphology and the crystallization behavior between separated fractions. Compared with ethylene oxide-ethylene terephthalate (EOET) segmented copolymer, compositional heterogeneity in EOBT segmented copolymer is weaker. But the compositional heterogeneity in EOBT segmented copolymer with long soft segment and high hard segment content is still obvious.展开更多
Well - defined diblock copolymers Of styrene (St ) and ethylene oxide (EO )have been prepared by sequential living anionic polymerization of the twocomonomers in THF. Diphenyl methyl potassium has been used as initiat...Well - defined diblock copolymers Of styrene (St ) and ethylene oxide (EO )have been prepared by sequential living anionic polymerization of the twocomonomers in THF. Diphenyl methyl potassium has been used as initiator. Theblock copolymers were characterized in detail by methods Of size exclusion chromatography (SEC ) , 1H - Nab, FT - IR, dynamic mechanical analysis(Daal ) and WAXD.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
为了提高有机光伏器件的寿命,通常采用封装技术来限制太阳能电池在水氧中的暴露程度。尽管聚合物太阳能电池(organic solar cells,OSCs)封装领域的相关研究已取得系列进展,但文献中很少研究封装过程带来的损伤。以经典的聚-3已基噻吩为...为了提高有机光伏器件的寿命,通常采用封装技术来限制太阳能电池在水氧中的暴露程度。尽管聚合物太阳能电池(organic solar cells,OSCs)封装领域的相关研究已取得系列进展,但文献中很少研究封装过程带来的损伤。以经典的聚-3已基噻吩为给体,[6,6]-苯基-C_(61)-丁酸甲酯为受体,通过将哌嗪作为第三组分提高器件稳定性,以氧化锌(ZnO)和三氧化钼(MoO_(3))为传输层材料制备倒置结构OSCs,系统考察大规模卷对卷器件封装中常用的紫外线(ultraviolet,UV)固化粘合剂对器件光电转化效率和稳定性的影响。结果表明,随着辐照时间的延长,UV胶封装器件的性能(开路电压、短路电流密度、填充因子和光电转化效率)呈持续下降趋势,更换MoO_(3)/Al电极后老化器件性能恢复,证实MoO_(3)/Al界面破坏是器件性能衰减的重要原因。激光束诱导电流成像显示UV胶封装出现由边缘向中心的失效过程。据此,提出如下的降解机理:UV胶中的光引发剂在紫外光照射下会产生强的质子酸,产生的质子酸与MoO_(3)发生反应,阻碍了空穴的有效传输,最终使得器件效率大幅度下降。此外,还开发出一种有效的OSCs器件用乙烯-醋酸乙烯酯共聚物膜封装工艺。本研究指出了UV胶固化粘合剂封装工艺的问题,同时也为提高聚合物太阳能电池的稳定性提供了新策略。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.
文摘The thermally stimulated shape memory behavior of ethylene oxide-butylene terephthalate (EOBT) segmented copolymers with different soft segment molecular weight and hard segment content was investigated. The deformation recovery ratio R-f of the EOBT samples increases with the soft segment molecular weight and the hard segment weight content, while the average overall deformation recovery speed V-r increases with the hard segment content. The temperature of maximum deformation recovery speed (T-M) is determined by the melting temperature of the soft segment crystals and the stability of the crystallized hard segment domains.
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.
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.
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.
文摘A series of ethylene oxide-ethylene terephthalate segmented copolymers (EOET) weresynthesized and complexed with LiClO_4 to form some new polymer electrolytes. The EOET-LiClO_4 electrolytes exhibit not only high ionic conductivity, but also good mechanical strengthand toughness. The EOET 3400--25--LiClO_4 complex possesses the highest conductivity (4. 65×10^(-5)s·cm^(-1) at room temperature when the ratio [Li^+]/[EO] equals 1/16. The structures of these electrolytes were examined with FTIR analysis, X-ray diffractionand DSC thermograms, and the results of high ionic conductivity of the segmented copolymerswere discussed.
基金This work was supported by the National Natural Science Foundation of China and the National Key Projects for Fundamental Research"Macromolecule Condensed State",The State Science and TechnologyCommission of China.
文摘A series of ethylene oxide-butylene terephthalate (EOBT) segmented copolymers with different soft segment length and hard segment content were synthesized. The compositional heterogeneity was studied by solvent extraction. The results show that the compositional heterogeneity increases when soft segment length and hard segment content increase. The compositional heterogeneity is also reflected in the crystallization behavior and morphology of soft and hard segment in EOBT segmented copolymer. The more compositional heterogeneous the EOBT segmented copolymer is, the more different the morphology and the crystallization behavior between separated fractions. Compared with ethylene oxide-ethylene terephthalate (EOET) segmented copolymer, compositional heterogeneity in EOBT segmented copolymer is weaker. But the compositional heterogeneity in EOBT segmented copolymer with long soft segment and high hard segment content is still obvious.
文摘Well - defined diblock copolymers Of styrene (St ) and ethylene oxide (EO )have been prepared by sequential living anionic polymerization of the twocomonomers in THF. Diphenyl methyl potassium has been used as initiator. Theblock copolymers were characterized in detail by methods Of size exclusion chromatography (SEC ) , 1H - Nab, FT - IR, dynamic mechanical analysis(Daal ) and WAXD.
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).
文摘为了提高有机光伏器件的寿命,通常采用封装技术来限制太阳能电池在水氧中的暴露程度。尽管聚合物太阳能电池(organic solar cells,OSCs)封装领域的相关研究已取得系列进展,但文献中很少研究封装过程带来的损伤。以经典的聚-3已基噻吩为给体,[6,6]-苯基-C_(61)-丁酸甲酯为受体,通过将哌嗪作为第三组分提高器件稳定性,以氧化锌(ZnO)和三氧化钼(MoO_(3))为传输层材料制备倒置结构OSCs,系统考察大规模卷对卷器件封装中常用的紫外线(ultraviolet,UV)固化粘合剂对器件光电转化效率和稳定性的影响。结果表明,随着辐照时间的延长,UV胶封装器件的性能(开路电压、短路电流密度、填充因子和光电转化效率)呈持续下降趋势,更换MoO_(3)/Al电极后老化器件性能恢复,证实MoO_(3)/Al界面破坏是器件性能衰减的重要原因。激光束诱导电流成像显示UV胶封装出现由边缘向中心的失效过程。据此,提出如下的降解机理:UV胶中的光引发剂在紫外光照射下会产生强的质子酸,产生的质子酸与MoO_(3)发生反应,阻碍了空穴的有效传输,最终使得器件效率大幅度下降。此外,还开发出一种有效的OSCs器件用乙烯-醋酸乙烯酯共聚物膜封装工艺。本研究指出了UV胶固化粘合剂封装工艺的问题,同时也为提高聚合物太阳能电池的稳定性提供了新策略。
