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利用偶氮型聚乙二醇大分子引发剂(VPE)引发苯乙烯进行无皂乳液聚合,制得了颗粒形态规整、单分散性较好的共聚物纳米微球。通过透射电子显微镜(TEM)和激光光散射(LLS)对微球的形态、粒径大小与分布进行了表征,同时考察了大分子引发剂VPE用量对聚合物纳米微球的粒径和聚合物乳液粘度的影响。实验结果表明:当苯乙烯的浓度固定在0.385mol/L时,随着VPE的浓度从1.2mmol/L增加到4.8mmol/L,聚合物纳米微球的粒径从178nm减少到70nm,而聚合物乳液的黏度相应从1.93mPa.s增加到2.17mPa.s,说明微球粒径在一定范围内可控。由嵌段共聚物的结构可推测该聚合物纳米微球的形成机理与传统乳液聚合体系不同,属于自组装成核,形成的微球具有核壳结构,这提供了一种简便制备嵌段共聚物纳米微球的方法。
Azo-type polyethylene glycol macromolecular initiator (VPE) was used to initiate the soap-free emulsion polymerization of styrene to prepare a copolymer nanosphere with regular monodisperse morphology and good monodispersity. Morphology, particle size and distribution of the microspheres were characterized by transmission electron microscopy (TEM) and laser light scattering (LLS). The effects of the amount of the macroinitiator VPE on the particle size of the polymer nanospheres and the polymer Effect of emulsion viscosity. The experimental results show that when the concentration of styrene is fixed at 0.385mol / L, the particle size of polymer nanospheres decreases from 178nm to 70nm with the increase of VPE concentration from 1.2mmol / L to 4.8mmol / L, while the polymerization The viscosity of the emulsion increased from 1.93mPa.s to 2.17mPa.s accordingly, indicating that the particle size of the microspheres can be controlled within a certain range. From the structure of the block copolymer, it can be inferred that the formation mechanism of the polymer nano-microspheres is different from that of the conventional emulsion polymerization system and belongs to the self-assembly nucleation and the formed microspheres have a core-shell structure, which provides a simple and convenient method for preparing the block copolymer Methods of nanospheres.