成核剂对PET晶体形态及力学性能的影响

Effect of Nucleation Agent on Morphology and Mechanical Properties of PET

通过高温下聚对苯二甲酸乙二酯(PET)熔体的结晶速率常数和球晶出现时间研究了不同成核剂对成核速率的影响,利用偏光显微镜、X射线衍射分析了成核剂对晶体形态的影响,结合退火处理研究了晶粒尺寸、成核剂对PET力学性能的影响。结果表明,成核剂的加入起到了快速成核和晶粒细化的效果,提高了材料的拉伸强度与缺口冲击强度,其中0.5%的成核剂Aclyn对PET的增韧改性效果最好,可使冲击强度增大2.2倍,同时使拉伸强度增大1.9倍。样品退火处理2 h后由于晶粒尺寸的增大其缺口冲击强度下降34%。

The effect of additives on the nucleating rate of PET melt was studied by the crystallization rate parameter and the appearance time of spherulites.The crystal morphology of PET / nucleation agents was measured by polarizing optical microscopy and X-ray diffraction.Combined the annealing treatment, the effects of grain size and nucleation agent on the mechanical properties of PET were studied.The results showed that rapid nucleation of melted PET caused by nucleating agent resulted in the decrease in grain size and both the notched impact and tensile strength of PET were improved.Aclyn was the most effective nucleation agent on toughening modification of PET, the impact strength and the tensile strength increased 3.2 times and 2.9 times respectively when the content of Aclyn was 0.5%.The notched impact strength of sample decreased 34% due to the increase of grain size caused by annealing for 2 hours.