Monte Carlo simulation is applied, with a high effectiveness and versatility, to the studies on the kinetics and chain length distribution in radical polymerization with RAFT process. The results show that the molecul...Monte Carlo simulation is applied, with a high effectiveness and versatility, to the studies on the kinetics and chain length distribution in radical polymerization with RAFT process. The results show that the molecular weight the resulting polymers increase linearly with monomer conversion, and the polydispersity is lower than 1.1, a typical feature of living polymerization. The simulation results are in consistent with the experimental results in literature. Additionally, that the molecular weight is proportional to the initial concentration of dithioester, [DSE]0, and the polymerization rate is [DSE]0-independent, could be of great help for controlling molecular weight in experiment.展开更多
Atom transfer radical polymerization (ATRP) of glycidyl methacrylate (GMA) at roomtemperature was carried out in a methylethyl ketone/1-propanol (in 7/3 volume ratio) solution,initiated and catalyzed by ethyl 2-bromop...Atom transfer radical polymerization (ATRP) of glycidyl methacrylate (GMA) at roomtemperature was carried out in a methylethyl ketone/1-propanol (in 7/3 volume ratio) solution,initiated and catalyzed by ethyl 2-bromopropionate (BRA)/CuC1/2,2＇ -bipyridine (BPY). Polymer ofGMA with planned molecular weight and narrow molecular weight distribution was obtained. In caseof bulk polymerization with the same initiator and catalyst the molecular weight of the polymerobtained was 1.5～2. 1 times greater than that of the above one. By using 1-phenylethyl chloride(PECl)/CuCl/BPY as catalyst controlled ATRP of GMA has failed whether it was in bulk or insolution.展开更多
文中聚焦温敏聚合物的响应机理,通过单电子转移活性自由基聚合法(SET-LRP),以溴化亚铜/三-(2-二甲氨基乙基)胺(CuBr/Me_(6)TREN)原位歧化得到的初生零价铜(Cu^(0))及二价铜与混合配体的络合物(Cu^(Ⅱ)Br_(2)/Me_(6)TREN/PMDETA)为催化体...文中聚焦温敏聚合物的响应机理,通过单电子转移活性自由基聚合法(SET-LRP),以溴化亚铜/三-(2-二甲氨基乙基)胺(CuBr/Me_(6)TREN)原位歧化得到的初生零价铜(Cu^(0))及二价铜与混合配体的络合物(Cu^(Ⅱ)Br_(2)/Me_(6)TREN/PMDETA)为催化体系,实现了温敏单体N-异丙基丙烯酰胺(NIPAM)和甜菜碱两性离子功能单体[2-(甲基丙烯酰基氧基)乙基]二甲基-(3-磺酸丙基)氢氧化铵(DMMPPS)的原位链延伸,制备得到了系列不同嵌段比的温敏聚合物P(NIPAM-b-DMMPPS)。采用核磁共振氢谱和红外光谱对聚合物结构进行了表征。以NIPAM加料比例为40%合成的P(NIPAM-b-DMMPPS)具有最低临界溶解温度(LCST)和最高临界溶解温度(UCST),分别为41℃和25℃。考察了NaCl浓度对P(NIPAMb-DMMPPS)LCST的影响,随着NaCl浓度的增大,LCST略降低。表面张力测试结果表明,表面活性聚合物溶液浓度为1×10^(-2)g/L时,表面张力降低至45 m N/m。P(NIPAM-b-DMMPPS)在石蜡/水体系中表现出温度诱导的乳化-破乳行为,P(NIPAM-b-DMMPPS)吸附在油水界面形成乳液,提高P(NIPAM-b-DMMPPS)中PNIPAM嵌段的比例能够实现从“低温乳化、高温破乳”向“高温乳化、低温破乳”的转变,其在油水乳化破乳领域有良好的应用前景。展开更多
文摘Monte Carlo simulation is applied, with a high effectiveness and versatility, to the studies on the kinetics and chain length distribution in radical polymerization with RAFT process. The results show that the molecular weight the resulting polymers increase linearly with monomer conversion, and the polydispersity is lower than 1.1, a typical feature of living polymerization. The simulation results are in consistent with the experimental results in literature. Additionally, that the molecular weight is proportional to the initial concentration of dithioester, [DSE]0, and the polymerization rate is [DSE]0-independent, could be of great help for controlling molecular weight in experiment.
文摘Atom transfer radical polymerization (ATRP) of glycidyl methacrylate (GMA) at roomtemperature was carried out in a methylethyl ketone/1-propanol (in 7/3 volume ratio) solution,initiated and catalyzed by ethyl 2-bromopropionate (BRA)/CuC1/2,2＇ -bipyridine (BPY). Polymer ofGMA with planned molecular weight and narrow molecular weight distribution was obtained. In caseof bulk polymerization with the same initiator and catalyst the molecular weight of the polymerobtained was 1.5～2. 1 times greater than that of the above one. By using 1-phenylethyl chloride(PECl)/CuCl/BPY as catalyst controlled ATRP of GMA has failed whether it was in bulk or insolution.
文摘文中聚焦温敏聚合物的响应机理,通过单电子转移活性自由基聚合法(SET-LRP),以溴化亚铜/三-(2-二甲氨基乙基)胺(CuBr/Me_(6)TREN)原位歧化得到的初生零价铜(Cu^(0))及二价铜与混合配体的络合物(Cu^(Ⅱ)Br_(2)/Me_(6)TREN/PMDETA)为催化体系,实现了温敏单体N-异丙基丙烯酰胺(NIPAM)和甜菜碱两性离子功能单体[2-(甲基丙烯酰基氧基)乙基]二甲基-(3-磺酸丙基)氢氧化铵(DMMPPS)的原位链延伸,制备得到了系列不同嵌段比的温敏聚合物P(NIPAM-b-DMMPPS)。采用核磁共振氢谱和红外光谱对聚合物结构进行了表征。以NIPAM加料比例为40%合成的P(NIPAM-b-DMMPPS)具有最低临界溶解温度(LCST)和最高临界溶解温度(UCST),分别为41℃和25℃。考察了NaCl浓度对P(NIPAMb-DMMPPS)LCST的影响,随着NaCl浓度的增大,LCST略降低。表面张力测试结果表明,表面活性聚合物溶液浓度为1×10^(-2)g/L时,表面张力降低至45 m N/m。P(NIPAM-b-DMMPPS)在石蜡/水体系中表现出温度诱导的乳化-破乳行为,P(NIPAM-b-DMMPPS)吸附在油水界面形成乳液,提高P(NIPAM-b-DMMPPS)中PNIPAM嵌段的比例能够实现从“低温乳化、高温破乳”向“高温乳化、低温破乳”的转变,其在油水乳化破乳领域有良好的应用前景。
