苯乙烯与N-对位取代苯基马来酰亚胺的乳液共聚

Emulsion Copolymerization of Styrene with N-p-Substituted Phenyl Maleimide

合成了苯乙烯(St)与N-对位取代基马来酰亚胺的3种二元共聚物乳液。在苯乙烯与N-对位取代苯基马来酰亚胺(N-p-RPhMI)的最大共聚比内,通过种子滴加乳液聚合制得高稳定性、高固含量(40%)、低粘度的共聚物乳液。研究了N-p-RPhMI苯环对位上取代基团对共聚物乳液的性能以及共聚物热性能影响。结果表明:N-p-RPhMI的加入提高了乳液的产率,并且随着取代基团极性的增强,乳液产率提高,乳胶粒的平均粒径增大,乳液的表观粘度降低;共聚物的热分解温度随着取代基团极性的增加而提高,但取代基极性对共聚物的玻璃化转变温度(Tg)的影响明显。同时,St/N-对甲氧基马来酰亚胺(N-p-MOPhMI)体系中助溶剂的加入对共聚物乳液性能影响很大,使共聚物的热起始分解温度升高,但对共聚物的Tg基本无影响。

The synthesis and characterization of copolymer emulsions of styrene and three types of N-p-substituted phenyl maleimide （N-p-RPhMI） （R ： Methyl, Chloro, Methoxy） were investigated. The copolymer emulsions were synthesized by varying the mole fraction of N-p-substituted phenyl maleimide and using a seed emulsion polymerization process. The emulsion was steady with high yield, low intrinsic viscosity, high solids （40%）. The yield and particle size of emulsion were increased and the intrinsic viscosity was decreased with polar substituents. The more polar substituents, the higher the initial decomposition temperature of copolymer is. The effect of polar substituents on glass transition temperature of copolymer is apparent. Meanwhile, St/N-p-MOPhMI copolymerization system with auxiliary solvent has great effect on the emulsion＇s performance and the copolymer＇s Ti, but has little influence on Tg of the copolymer.