拉伸速率对尼龙6力学性能和颈缩区结晶度的影响

以己内酰胺为原料,通过开环聚合法制备了尼龙6材料。利用电子万能试验机对尼龙6材料进行了10,20,50 mm/min三种不同速率的拉伸实验,结果表明,随着拉伸速率的增加,尼龙6的屈服强度略有增加,而断裂伸长率和断裂能则大为减少。利用差示扫描量热仪对拉伸后试件的结晶度进行了测试,结果表明,在颈缩区有新的晶型生成;随着拉伸速率的增加,结晶度也随之增大,当拉伸速率为50 mm/min时,其颈缩区结晶度比初始结晶度提高了27.5%。

Effect of Tensile Rates on Mechanical Properties and Necking Zone Crystallinity of Nylon 6

With caprolactam as raw material,the nylon 6 materials were prepared by the ring opening polymerization method.The mechanical properties of nylon 6 materials were measured in three different rates about 10,20,50 mm/min by the electronic all-powerful tester.The results showed that the yield strength of the nylon 6 materials slightly increased,while the breaking elongation and fracture energy considerably reduced with the increase of tensile rate.The crystallinity of the samples after stretching was measured by differential scanning calorimetry.The results showed that a new crystal type generated in the necking zone;with the increase of tensile rate,the crystallinity of nylon 6 materials increased.When the tensile rate was 50 mm/min,the necking zone crystallinity was improved 127.5% than the initial crystallinity.