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以2-{[(十二烷基硫基)硫代甲酰基]硫烷基}琥珀酸(DCTSS)为链转移剂(CTA)在水溶液中调控丙烯酸(AA)进行可逆加成-断裂链转移自由基聚合(RAFT)。考察了引发剂种类、聚合温度、n(引发剂)/n(CTA)、n(AA)/n(CTA)、时间对丙烯酸聚合的影响。结果表明,以4,4′-偶氮二(4-氰基戊酸)(V501)为引发剂,聚合反应具有活性可控聚合的特征,聚合动力学呈线性关系,聚合物的黏均相对分子质量(以下简称黏均分子量)随转化率的增加而线性增加,得到分子量可控、分布为1.50左右的聚合物;升高温度可以加快反应速率,使黏均分子量分布降低,反应更加可控;降低n(V501)/n(CTA)值可以使聚合产物的黏均分子量升高,但聚合速率也会降低;随着n(AA)/n(CTA)值的增加,聚合产物的黏均分子量也增加,并且基本呈线性关系;最佳反应时间为2h;用所得聚合物作为大分子RAFT试剂,丙烯酸正丁酯(BA)为单体进行扩链反应,得到聚丙烯酸-b-聚丙烯酸正丁酯;用核磁共振氢谱、傅立叶变换红外光谱对产物结构进行了表征。
The reversible addition-fragmentation chain transfer of acrylic acid (AA) was controlled by aqueous 2 - {[(dodecylthio) thiocarbonyl] sulfanyl} succinic acid (DCTSS) as chain transfer agent Free Radical Polymerization (RAFT). The effects of initiator type, polymerization temperature, n (initiator) / n (CTA), n (AA) / n (CTA) and time on the polymerization of acrylic acid were investigated. The results showed that the polymerization reaction was controlled by 4,4’-azobis (4-cyanovaleric acid) (V501). The polymerization kinetics showed a linear relationship with the viscosity of the polymer being relatively Molecular weight (hereinafter referred to as viscosity average molecular weight) increases linearly with the increase of conversion rate to obtain a polymer with a controlled molecular weight of about 1.50. Increasing the temperature can speed up the reaction rate, decrease the viscosity average molecular weight distribution and make the reaction more controllable ; Decreasing the value of n (V501) / n (CTA) can increase the viscosity average molecular weight of the polymerization product, but the polymerization rate decreases. With the increase of n (AA) / n The molecular weight also increased, and the basic linear relationship; the optimal reaction time was 2h; with the resulting polymer as a macro RAFT agent, n-butyl acrylate (BA) as a monomer chain extension reaction, polyacrylic acid -b- polyacrylic acid N-butyl ester. The structure of the product was characterized by 1H nuclear magnetic resonance and Fourier transform infrared spectroscopy.