模具温度和冷却时间对α成核剂改性PP制品结晶行为与力学性能的影响

Effects of Mold Temperature and Cooling Time on Crystallization and Mechanical Properties of Polypropylene Modified by α-nucleator

研究了不同模具温度和不同冷却时间对添加α成核剂聚丙烯(PP)结晶行为和力学性能的影响。采用差示扫描量热法(DSC)、偏光显微镜等进行测试。结果表明,较低模具温度(180℃)和较短冷却时间(1 h)成型的PP制品,其结晶温度较低,结晶速度较快,球晶细小均匀,导致其拉伸强度和韧性提高。

The effects of the mold temperatures and cooling time on the crystallization and mechanical properties of polypropylene modified by α - nucleator were studied by means of polarized optical microscopy （POM）, differential scanning calorimetry （DSC）. The results showed that the PP products with a lower mold temperature of 180 ℃ and a shorter cooling time of 1 h had a lower crystallization temperature and a faster crystallization rate; the spherulites became smaller and more even, resulted in the increase of the tensile strength and the toughness.