Abstract

Two chain extenders having different molecular structures; an alternating copolymer of ethylene and maleic anhydride (EMA) and a novel chain extender, dimeric 2,4-toluene diisocyanate (DTDI), both at two different concentrations (0.5 and 1 wt%), were melt compounded with recycled polyamide 6 (rPA6) using a twin-screw extruder. In order to investigate the effect of temperature profile and residence time on the chain extension behaviors of these chain extenders three different temperature profiles and four different throughput rates were selected for the melt compounding. Effects of the parameters were observed through differential scanning calorimetry (DSC) measurements, relative viscosity measurements, and tensile and impact tests. Temperature and time dependent improvements of the chain extended products with EMA and DTDI showed different tendencies. While chain extension of rPA6 with EMA became more effective with the optimization of the barrel temperature profile, chain extension with DTDI was not affected by temperature changes. By adjusting the temperature profile 9.1% higher viscosity, 1.3 times higher elongation at break and 10.6% higher impact strength were obtained for the chain extension reaction of rPA6 with EMA. Longer residence time promoted the chain extension reaction of rPA6 with EMA. On the other hand, chain extension of rPA6 with DTDI was not significantly affected by residence time.

摘要

两个具有不同分子结构的扩链剂；将乙烯和马来酸酐的交替共聚物（EMA）和新型扩链剂二聚的2,4-甲苯二异氰酸酯（DTDI）（两种浓度分别为0.5和1 wt％）与回收的聚酰胺6（rPA6）熔融混合。 ）使用双螺杆挤出机。为了研究温度曲线和停留时间对这些扩链剂的扩链行为的影响，选择了三种不同的温度曲线和四种不同的吞吐速率进行熔融配混。通过差示扫描量热法（DSC）测量，相对粘度测量以及拉伸和冲击测试观察到参数的影响。EMA和DTDI对链延长产品的温度和时间依赖性改进显示出不同的趋势。虽然rPA6与EMA的扩链随着机筒温度分布的优化变得更加有效，但DTDI的扩链不受温度变化的影响。通过调节温度曲线，可以使rPA6与EMA的扩链反应的粘度提高9.1％，断裂伸长率提高1.3倍，冲击强度提高10.6％。更长的停留时间促进了rPA6与EMA的扩链反应。另一方面，rPA6与DTDI的链延伸不受停留时间的影响。DTDI的扩链不受温度变化的影响。通过调节温度曲线，可以使rPA6与EMA的扩链反应的粘度提高9.1％，断裂伸长率提高1.3倍，冲击强度提高10.6％。更长的停留时间促进了rPA6与EMA的扩链反应。另一方面，rPA6与DTDI的链延伸不受停留时间的影响。DTDI的扩链不受温度变化的影响。通过调节温度曲线，可以使rPA6与EMA的扩链反应的粘度提高9.1％，断裂伸长率提高1.3倍，冲击强度提高10.6％。更长的停留时间促进了rPA6与EMA的扩链反应。另一方面，rPA6与DTDI的链延伸不受停留时间的影响。