中文摘要：

考察了工艺参数对稀土β成核剂改性聚丙烯（β—PP）力学性能的影响。当注射速率在20～80mm／s变动时，β—PP冲击强度的最大值与最小值相比提高了12．2％，熔体温度在190～250℃、保压压力在20～50MPa和保压时间在2～60s变动时，冲击强度相对应的提高幅度分别为22．2％，31．8％和97．7％；同时对比了不同工艺条件对α—PP（未添加β成核剂聚丙烯）和β-PP冲击性能影响的差异。结果表明，β—PP对注射工艺条件的变化更敏感。

英文摘要：

The influence of injection processing parameters on the mechanical properties of polypropylene modified by a rare earth β nucleating agent was investigated. Within the range of injection speed varied from 20 mm/s to 80 mm/s, the increment between the maximum and minimum of impact strength is 12.2% ,while that value of increased range of impact strength corresponding to melting temperature changing from 190 ℃ to 250 ℃, holding pressure from 20 MPa to 50 MPa and holding time from 2 s to 60 s are 22.2%, 31.8%and 97.7 % respectively. The effects of the injection condition on the impact strength of α-PP and β-PP system were comparatively studied. The results show that β-PP modified by rare earth nucleating agent is more sensitive to the change of injection process condition than α-PP.