利用原子转移自由基聚合(ATRP)方法,由单体2-(2-甲氧基乙氧基)甲基丙烯酸乙酯(MEO2MA)和寡聚(乙二醇)甲基醚甲基丙烯酸酯(OEGMA,Mn=500 g mol–1)合成了无规共聚物P(MEO2MA-co-OEGMA).并采用动态光散射(DLS)、紫外光谱及透射电子显微镜(...利用原子转移自由基聚合(ATRP)方法,由单体2-(2-甲氧基乙氧基)甲基丙烯酸乙酯(MEO2MA)和寡聚(乙二醇)甲基醚甲基丙烯酸酯(OEGMA,Mn=500 g mol–1)合成了无规共聚物P(MEO2MA-co-OEGMA).并采用动态光散射(DLS)、紫外光谱及透射电子显微镜(TEM)等技术考察聚合物在水溶液中的温度响应性聚集行为,获得其在水溶液中的最低临界溶解温度(LCST)及其随组成的变化规律.结果表明,该聚合物具有良好且可逆的温度响应行为,这主要归因于聚合物与水分子之间氢键作用,及其分子本身疏水作用之间为了保持一种微妙的动态平衡而自发对聚集形态进行的"自我调整",从而达到新的热力学平衡状态的结果.该聚合物的LCST与聚合物中单体OEGMA所占的摩尔比例呈线性关系,可以通过改变单体的摩尔配比实现对聚合物LCST的调控.展开更多
Microbial synthesis of functional polymers has become increasingly important for industrial biotechnology. For the first time, it became possible to synthesize controllable composition of poly（3-hydroxyalkanoate） （...Microbial synthesis of functional polymers has become increasingly important for industrial biotechnology. For the first time, it became possible to synthesize controllable composition of poly（3-hydroxyalkanoate） （P3HA） consisting of 3-hydroxydodec- anoate （3HDD） and phenyl group on the side-chain when chromosome of Pseudomonas entomophila was edited to weaken its t-oxidation. Cultured in the presence of 5-phenylvaleric acid （PVA）, the edited P. entomophila produced only homopolymer poly（3-hydroxy-5-phenylvalerate） or P（3HPhV）. While copolyesters P（3HPhV-co-3HDD） of 3-hydroxy-5-phenylvalerate （3HPhV） and 3-hydroxydodecanoate （3HDD） were synthesized when the strain was grown on mixtures of PVA and dodecanoic acid （DDA）. Compositions of 3HPhV in P（3HPhV-co-3HDD） were controllable ranging from 3% to 32% depending on DDDA/PVA ratios. Nuclear magnetic resonance （NMR） spectra clearly indicated that the polymers were homopolymer of P（3HPhV） and random copolymers of 3HPhV and 3HDD. Their mechanical and thermal properties varied dramatically de- pending on the monomer ratios. Our results demonstrated the possibility to produce tailor-made, novel functional PHA using the chromosome edited P. entomophila.展开更多
文摘利用原子转移自由基聚合(ATRP)方法,由单体2-(2-甲氧基乙氧基)甲基丙烯酸乙酯(MEO2MA)和寡聚(乙二醇)甲基醚甲基丙烯酸酯(OEGMA,Mn=500 g mol–1)合成了无规共聚物P(MEO2MA-co-OEGMA).并采用动态光散射(DLS)、紫外光谱及透射电子显微镜(TEM)等技术考察聚合物在水溶液中的温度响应性聚集行为,获得其在水溶液中的最低临界溶解温度(LCST)及其随组成的变化规律.结果表明,该聚合物具有良好且可逆的温度响应行为,这主要归因于聚合物与水分子之间氢键作用,及其分子本身疏水作用之间为了保持一种微妙的动态平衡而自发对聚集形态进行的"自我调整",从而达到新的热力学平衡状态的结果.该聚合物的LCST与聚合物中单体OEGMA所占的摩尔比例呈线性关系,可以通过改变单体的摩尔配比实现对聚合物LCST的调控.
基金supported by the National High Technology Research and Development Program of China(2012AA023102 to Liu Lei,Guo Kai and Wu Qiong)the National Basic Research Program of China(2012CB725201 to Chen GuoQiang and Chen JinChun,2012CB725204 to Guo Kai and Wu Qiong)National Natural Science Foundation of China(31270146 to Chen GuoQiang)
文摘Microbial synthesis of functional polymers has become increasingly important for industrial biotechnology. For the first time, it became possible to synthesize controllable composition of poly（3-hydroxyalkanoate） （P3HA） consisting of 3-hydroxydodec- anoate （3HDD） and phenyl group on the side-chain when chromosome of Pseudomonas entomophila was edited to weaken its t-oxidation. Cultured in the presence of 5-phenylvaleric acid （PVA）, the edited P. entomophila produced only homopolymer poly（3-hydroxy-5-phenylvalerate） or P（3HPhV）. While copolyesters P（3HPhV-co-3HDD） of 3-hydroxy-5-phenylvalerate （3HPhV） and 3-hydroxydodecanoate （3HDD） were synthesized when the strain was grown on mixtures of PVA and dodecanoic acid （DDA）. Compositions of 3HPhV in P（3HPhV-co-3HDD） were controllable ranging from 3% to 32% depending on DDDA/PVA ratios. Nuclear magnetic resonance （NMR） spectra clearly indicated that the polymers were homopolymer of P（3HPhV） and random copolymers of 3HPhV and 3HDD. Their mechanical and thermal properties varied dramatically de- pending on the monomer ratios. Our results demonstrated the possibility to produce tailor-made, novel functional PHA using the chromosome edited P. entomophila.
