尼龙-6和尼龙-6合金的球晶结构与破坏性能的研究

成型冷却速度即结晶速度对单纯尼龙 ６和尼龙 ６合金的拉伸破坏性能具有不同的影响．结晶速度慢，球晶尺寸大，单纯尼龙 ６的拉伸破坏强度高，破坏形变和破坏能量减小；尼龙 ６／热塑性聚酰胺弹性体／增容剂合金不仅拉伸破坏强度高，而且破坏形变和破坏能量都有所增加．研究表明，虽然球晶尺寸影响尼龙 ６的破坏性能，但球晶的性质即球晶的界面上和片晶 片晶间的非晶部分结构、微小分散粒子的空洞化及相与相之间的界面结合强度是影响尼龙 ６破坏性能的主要因素．

THE EFFECT OF SPHERULIE CRYSTAL ON PROPERTIES OF TENSILE FRACTURE OF NYLON 6 AND NYLON 6 ALLOY

The work disscussed the effect of structure of spherulite on properties of pure nylon 6 and Nylon 6/TPAE/Compatibilizer alloy by the experiment of changing the cooling velocity when shaping.First,melts of pure nylon 6 and Nylon 6/TPAE/Compatibilizer alloy were cooled rapidly and slowly on the condition of 4℃ water and 23℃ air respectively.Second,they were made into specimens.Then,specimens were carried on observation of structure of spherulite and dispersioin morphology and analyses of absorbing heat,meanwhile by PLM,SEM and DSC,carried on the experiment of tensile fracture and interface tearing.The results show:(1) Dispersion particles are well distributed between interface and interior of spherulite or between lameller crystals.(2) The size of spherulit is greatly different when pure nylong 6 is cooled rapidly in 4℃ water.But that of spherulite is well distributed when it is cooled slowly in 23℃ air.The comparison of them shows the latter speciment's size of spherulite is large and fracture strength is high,with decreasing of deformation and energy of tensile fracture.(3) The size of spherulite is small but differs greatly when Nylon 6/TPAE/A8200 alloy was cooled rapidly in 4℃ water,but that of spherulite is large and well distributed in 23℃ air.The comparison of them shows the latter specimen's size of spherulite is large and fracture strength is high,with increasing the deformation and energy of tensile fracture.(4) On the same cooling condition,the change trend of size of spherulite of pure nylon 6 and nylon 6/TPAE/Compatibilizer alloy is same,but that of properties of tensile freacture is oppsite.This a because slow cooling contributes to not only the formation of large spherulite but also the enhancement of adhesion strength of interface between the dispersed phase TPAE and successive phase nylon 6.On the other hand,the dispersion of tiny TPAE particle in the interface and interior of nylon 6 spherulite strengthens the deformation ability of spherulite,and enhances the strength deformation and energy of tensile fracture.Pure nylon 6 has not these specific properties.Therefore,though the size of spherulite is one of factors which influence fracture properties of nylon 6,the interface of spherulite,non crystal stucture between lamellar crystals,voiding of tiny elastic and adhesion strength of phase interface are main factors which influence fracture properties of nylon 6.