Atom Transfer Radical Emulsion Polymerization And Synthesis Of New Type Block Copolymers

Polybutyl methylacrylate(PBMA) and a series of block copolymers have been synthesized by Atom Transfer Radical Polymerization(ATRP) emulsion polymerization or solution polymerization. The structures of polymers were investigated by IR,1H-NMR and DSC techniques. The molecular weight and polydispersities of polymers were determined by GPC. The controllability of polymerization, kinetics and polymerization mechanism were also studied. In order to investigate the mechanisms of particles' nucleation and growth, the morphology and size of particles' were monitored by TEM and PCS. The partitioning behavior of copper-based catalyst between the organic phase and aqueous phase was studied in detail using UV-Vis spectroscopy, the catalyst character of polymerization was also studied. The Cu content in the polymers was obtained by ICP-AES, the efficiency of catalysis and removal of copper-based catalyst were discussed. The results were as following:PBMA was prepared by ATRP emulsion polymerization in the presence of catalyst CuCl/dNbpy, nonionic surfactant Brij35, oil-solubility initiator BrCH3CHCOOC2H5. The polymerization process was controllable. The amount of catalyst, surfactant, initiator, and reaction time, temperature affected the polymerization and the properties of colloid emulsion. The morphology of particles was of a spherical structure, but there were great scaling on the surface, which was probably caused by the Cu complex. The size of the particle was larger than that of conventional polymerization. The latex particles nucleate was mainly via a micellar nucleation mechanism.PBMA-b-PSt diblock copolymer and PBMA-b-PSt-b-PBMA triblock copolymer were obtained by ATRP emulsion polymerization with PBMA and PSt macroinitiators also prepared by ATRP emulsion polymerization. The polymerization process was controllable, but the molecular weight didn't correspond well with theoretical value, the initiation efficiency was small. The studies of the effects of all kinds of factors on the controllability of polymerization and the properties of emulsion showed that macroinitiators had great effects on the polymerization. Increasing the molecular weight of macroinitiator, the polymer's molecular weight would deviate greatly from theoretical value, and the molecular weight distributions would broaden. But increasing the amount of macroinitiators, the polymerization rate would increase, thepolymer's molecular weight would deviate slightly from theoretical value, and molecular weight distributions would narrow down.Comparing the efficiency of catalysis and removal of copper-based catalyst of CuCl/dNbpy to CuCl/bpy in different polymerization systems showed that although CuCl/dNbpy had better catalysis efficiency, the removal efficiency of copper-based catalyst was less than CuCl/dNbpy. The Cu content of polymers after removal of copper-based catalyst in ATRP emulsion polymerization system was higher than that in bulk polymerization system.The PDMS macroinitiators containing terminal alkyl bromide groups were synthesized from vinylsilyl terminal PDMS or a , ω-dichloride PDMS respectively. PSt-b-PDMS-b-PSt and PBMA-b-PDMS-b-PBMA triblock copolymers were obtained by ATRP solution polymerization with those PDMS macroinitiators. The polymerization was controllable, with the increase of the monomer conversion, there was a nearly linear increase of molecular weight and a decrease of polydispersity in the process of the polymerization. The amount of macroinitiator, catalyst, and reaction time, temperature affected the polymerization. The polymerization mechanism was mainly via a Matyjaszewski's mechanism. The related kinetics equation nearly corresponded with that was predicted by theory.The studies of polymerization kinetics, mechanism of particles' nucleation of ATRP emulsion polymerization of BMA; PBMA-b-PSt diblock copolymer and PBMA-b-PSt-b-PBMA triblock copolymer obtained by ATRP emulsion polymerization with PBMA and PSt macroinitiators also prepared by ATRP emulsion polymerization; the PDMS macroinitiators c...