Synthesis And Compatibilizing Efficiency Of Block Polymer Anhy-PS-Br And Anhy-PS-Anth

Polymer blending would achieve new polymer materials with excellent combination properties. Due to the vast majority of polymers are mutually immiscible and thermodynamically unstable, the research of Polymer blending is focusing on compatible technologies. The compatibilizing efficiency of compatibilizer can be affected by its molecular architecture, molecular composition and the interaction between the homopolymers and the copolymer block. Therefore, it is very necessary to research the relationship of the structure and composition of copolymer and its compatibilizing efficiency. This thesis uses the block copolymer precursor as the compatibilizer of polymeric blends, compared by graft copolymer precursor, to establish the relationship of the structure and composition of compatibilizer and its compatibilizing efficiency, which is significant to optimize the structure and composition of compatibilizer in order to achieve the high compatibilizing efficiency. A novel block reactive tracer-mulsifier also was synthesized, which laid the foundation to study the morphology evolvement of industrial polymeric blends to building up an emulsification curve in continuous mixer. The results are as follows:1. Anhydride-terminated polystyrene (Anhy-PS-Br) was synthesized by atom transfer radical polymerization (ATRP) using 4-bromomethylphthalic anhydride as initiator, used as the block copolymer precursor in polymeric blends. During blending with polystyrene (PS) and polyamide 6 (PA6), Anhy-PS-Br reacted with PA6 to form block copolymer PS-b-PA6.2. The Anhy-PS-Br as a block copolymer precursor, copolymer (PS-co-TMI) of styrene (St) and 3-isopropenyl-a,a-dimethylbenzene isocyanate (TMI) and styrene-maleic anhydride (SMA) as graft copolymer precursor were selected to investigated on the effect of copolymer precursor on the compatibilizing efficiency and stabilization of PS/PA6 blends. Whether disperse/matrix blends or co-continuous blends, results show that the compatibilizing efficiency of Anhy-PS-Br is better than those of PS-co-TMI or SMA. Furthermore, comparing at stabilizing the morphology of the PS/PA6 (30/70) blends during quiescent annealing 15 min at 230℃, the compatibilizing efficiency of Anhy-PS-Br irrespective of its molecule weight is still better than those of PS-co-TMI.3. The effect of the backbone chain of graft copolymer PS-g-PA6 at compatibilizing the dispersed phase/matrix morphology of PS/PA6 blends was studied. Results showed that:In the disperse/matrix blends, when the graft chain of graft compatibilzer comaptibilizing with the matrix phase, the compatibilizing efficiency depended little on its length of backbone; when the graft chain of graft compatibilzer comaptibilizing with the dispersed phase, the efficiency depended very much on its length of backbone, the longer backbone chain, the worse the efficiency; the longer the graft, the better the efficiency. Therefore, the design principle of high efficiency of graft copolymer (precursor) for disperse/matrix phase is that:the dispersed as backbone homopolymer and the matrix as graft homopolymer to form the graft copolymer, and the longer the graft, the higher the efficiency; the dispersed as backbone chain distributed lots of functional group which can react with matrix phase.4. Anhydrde-polystyrene-anthracene (Anhy-PS-Anth) was synthesized by phthalic anhydrde end-functional polystyrene (Anhy-PS-Br) attached with 9-Anthracene-carboxylic acid through nucleophilic substitution. Anhy-PS-Anth was characterized by 1H NMR, FTIR, SEC and SEM and show that it can be uesed as the block reactive tracer-mulsifier for PS/PA6 blend systems.