摘要
聚氯乙烯(PVC)较好的耐酸碱性、强介电性及尺寸稳定性,使其得到了广泛的应用,但是,其分子链间作用力较强,使PVC树脂的韧性较差,限制了其应用范围.采用熔融共混法,将氯化聚乙烯(CPE)弹性粒子作为增韧剂,制备了一系列PVC/CPE共混物,分析CPE添加量及PVC种类(相对分子质量不同)对共混物性能的影响.结果表明,当CPE添加量为20份时,SG-5型PVC共混物的悬臂梁缺口冲击强度最大,其值为1 161 J/m,与纯PVC(28 J/m)相比,增大了40.5倍;当在CPE添加量为20份时,基体为PVC-5(相对分子质量在61 325～70 937之间),韧性达到最大,分别为PVC-1的3.8倍、PVC-3的5倍及PVC-8的6倍.由流变性能分析结果可知,当CPE添加量小于10份时,共混物的储能模量(G')和损耗模量(G")随添加量增加而增大;当CPE添加量大于10份时,共混物的G'和G"随添加量增加而减小.当CPE的添加量相同时,G'和G"随基体PVC相对分子质量减小而减小.SEM结果表明,随着CPE添加量的增加,共混物的塑性流动增强,韧性显著提高;当基体为PVC-5时,共混物的塑性流动最强,韧性最佳.
Abstract
Polyvinyl chloride's(PVC)outstanding acid and alkali resistance,strong dielectric dimensional stability,made it has a wide range of applications,but its strong intermolecular chain forces made PVC resin toughness was poor,limiting its further application.A series of PVC/CPE blends were prepared by melt blending method using chlorinated polyethylene(CPE)elastic particles as toughening agent to study the effects of CPE addition and PVC type(different PVC molecular weights)on the properties of the blends.The results showed that the impact strength was the largest when the CPE addition was 20 phr,reaching 1 161 J/m,which was 40.5 times larger than that of pure PVC(28 J/m).The toughness was found to be maximum at CPE addition of 20 phr when the matrix was PVC-5(molecular weight between 61 325～70 937),which was 3.8 times higher than that of PVC-1,5 times higher than that of PVC-3 and 6 times higher than that of PVC-8,respectively.The rheological property fraction found that the energy storage modulus(G')and loss modulus(G")of the blends increased with increase in addition before 10 phr and decreased with increase in addition after 10 phr.G'and G"decreased with decreasing molecular weight of the matrix PVC at the same addition amount.SEM revealed that the plastic flow of the blends was enhanced and the toughness was greatly improved by the increase of CPE addition;the plastic flow was the strongest and the toughness was the best when the matrix was PVC-5.
维普
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