(2-甲基丙烯酰氧乙基)三甲基氯化铵-丙烯酰胺双水相共聚合

将(2-甲基丙烯酰氧乙基)三甲基氯化铵(DMMC)与丙烯酰胺(AM)在聚乙二醇(PEG)水溶液中进行双水相共聚合(ATPC),并与DMMC/AM均相水溶液共聚合(HASC)进行比较.在均相水溶液共聚合体系中得到了DMMC/AM共聚体系的竞聚率分别为rDMMC=1.77、rAM=0.32,并给出了竞聚率的95%,99%联合置信区域.比较了两种共聚合体系的转化率-时间曲线和共聚组成,表明双水相共聚合体系初期反应速率高于均相水溶液共聚合体系,但最终转化率相似;两种共聚合体系得到的共聚物组成有较大差别.测得了DMMC、AM以及DMMC-AM共聚物(CPAM)在65℃、反应条件下的相分配系数为K1=0.035、K2=0.125和Kp=0.011.结合双水相聚合的本质以及单体和共聚物在两相的分配系数,提出了一个计算双水相共聚组成的新方法,用该方法计算的双水相共聚合体系的共聚组成与实验点吻合较好.

AQUEOUS TWO-PHASE COPOLYMERIZATION OF (2-METHACRYLOYLOXYETHYL)TRIMETHYLAMMONIUM CHLORIDE AND ACRYLAMIDE

The aqueous two-phase copolymerization(ATPC) of(2-methacryloyloxyethyl)trimethylammonium chloride(DMMC) and acrylamide(AM) in the aqueous solution of poly(ethylene glycol)(PEG) is studied and compared with homogeneous aqueous solution copolymerization(HASC).The reactivity ratios of DMMC/AM homogeneous aqueous solution copolymerization are r_(DMMC)=1.77 and r_(AM)=0.32.The 95% and 99% joint confidence regions are also calculated.The conversion versus time curves and the composition of DMMC-AM copolymers are compared in two copolymerization systems,which shows that the reaction rate of ATPC is more quickly than that of HASC,but the final conversions are almost the same;the composition of DMMC-AM copolymers in ATPC is obviously different from that of in HASC.The partition coefficients of DMMC,AM and the copolymer of DMMC-AM at 65℃,under the reaction condition are determined,K_1=0.035,K_2=0.125 and K_p=0.011,respectively.Base on the polymerization mechanism of ATPC and the partition coefficients of monomers and copolymer,a new method of calculating the copolymer composition is presented for ATPC.The copolymer composition calculated by this method is in agreement with the experiment data.