超支化聚酯改善聚己内酰胺增韧性能的应用

Application of Hyper-branched Polyesteron Toughening Performance of Polycaprolactam

增韧聚酰胺体系存在聚酰胺基体与增韧剂之间相容性不足、刚韧平衡难以兼顾的问题,为了寻找优化的方案,本文以乙烯-1-辛烯共聚物接枝马来酸酐(POE-g-MAH)增韧改性聚己内酰胺(PA6)为研究对象,探究超支化聚酯HD-5000对该增韧体系力学性能的影响,并用扫描电子显微镜观察材料断面的微观形貌。结果表明,随着增韧剂含量增加,材料存在脆韧转变区间,该区间内提高约1%-2%的增韧剂含量,材料的缺口冲击强度增加近100%。材料韧性差异使断面表现出不同的微观形貌。HD-5000的加入有效降低了PA6发生脆韧转变的增韧剂含量,有利于在较好地保持材料拉伸、弯曲强度的同时大幅度提高其缺口冲击强度;利用HD-5000丰富的端羟基结构,提高了橡胶相在尼龙体系中的分散程度,分散相从粒径较大且尺寸分布较宽的棒状形貌发展为粒径较小分布较窄的球状粒子。

The insufficient compatibility between polyamide matrices and elastomers limits the use of toughening modified polyamide materials due to the poor performanceon rigid and tough balance.Attempts were made to optimizetheformula,based on toughenedpolycaprolactam(PA6)obtained with ethylene-1-octene copolymer grafted maleic anhydride(POE-g-MAH),effects of hyper-branched polyester on mechanical properties of such toughened PA6 were studied.The cross-section of the materials was observed by using scanning electron microscope(SEM),thereby the morphology of elastomer in PA6 being further discussed.The results showed PA6 materials experienced brittle-ductile transition as increasing the content of toughener in which the notched impact strength of materials was twice by increasing about 1%-2% of toughener.Materials with different toughness had distinct morphology of section.With addition of HD-5000,addition level of elastomer in PA6 at which the brittle-ductile transition occurred was decreased.The impact resistant performance was profoundly improved without negatively affecting flexural and tensile strength.It was believed to be due to the factor that HD-5000 enhanced the dispersion of elastomer in the PA6 composites which can be attributed to the high concentration of hydroxyl end group.The rough and rod-shape dispersed elastomer phase was developed into spherical particles with narrow-distributed and small particle sizes.