弹性体的结构设计及其共聚氯乙烯的接枝与增韧机理研究-高分子化学与物理专业论文.docxVIP

弹性体的结构设计及其共聚氯乙烯接枝与增韧机理研究 弹性体的结构设计及其共聚氯乙烯接枝与增韧机理研究 STUDY ON THE STRUCTURE DESIGN OF ELASTOMER AND THE GRAFTING AND TOUGHENING MECHANISM OF ELASTOMER COPOLYMERIZATION WITH VINYL CHLORIDE ABSTRACT P(nBA-co-St)/PVC composite resins were prepared via two-step seeded emulsion copolymerization. Firstly, P(nBA-co-St) copolymer latex was synthesized using n-butyl acrylate (nBA) and styrene (St) through semicontinuous seeded emulsion copolymerization, then the P(nBA-co-St) copolymer latexes were copolymerized with vinyl chloride monomer (VCM). Morphological structure of the composite particles and blending materials were characterized by Laser particle size analyzer (LPSA), scanning electron microscope (SEM), transmission electron microscope (TEM), differential scanning calorimeter (DSC), dynamic mechanical analyzer (DMA) and Charpy impact test machine. And the grafting situation of the P(nBA-co-St)/PVC composite particles was characterized by Soxhlet solvent extraction, Gel penetration chromatography (GPC), Fourier transform infrared spectroscopy (FTIR) and Nuclear Magnetic Resonance (1H-NMR). Effects of different monomer feed ratios on the particle morphology, grafting ratios (GR) of the composite particles, and the glass transition temperatures (Tgs), mechanical properties of the composite materials were investigated in detail. The LPSA result demonstrated that the PVC chains were successfully coated onto the surface of the P(nBA-co-St) latex particles, as growth in sizes of the composite particles after the P(nBA-co-St) grafted by PVC. The SEM graphs also corroborated this result, and the composite particles presented clearly core-shell morphology in TEM graphs. The P(nBA-co-St)-g-PVC was ii 河北工业大学硕士学位论文 河北工业大学硕士学位论文 separated from the P(nBA-co-St)/PVC composite resins via Soxhlet solvent extraction technology. FTIR and 1H-NMR study results showed that the PVC reasonably grafted onto the P(nBA-co-St) chains. The phenomenon of retardation polymerization appeared