中国塑料 ›› 2024, Vol. 38 ›› Issue (5): 7-13.DOI: 10.19491/j.issn.1001-9278.2024.05.002

• 材料与性能 • 上一篇    下一篇

高熔体流动速率抗冲共聚聚丙烯的结构与性能研究

郭明海()   

  1. 中石化宁波新材料研究院有限公司,浙江 宁波 315207
  • 收稿日期:2023-09-28 出版日期:2024-05-26 发布日期:2024-05-20
  • 作者简介:郭明海(1969—),男,高级工程师,主要研究方向为聚烯烃新产品,guomh.zhlh@sinopec.com

Studies on structure and properties of high⁃impact copolymerized polypropylene with high melt flow rate

GUO Minghai()   

  1. Sinopec Ningbo New Materials Research Institute Company Limited,Ningbo 315207,China
  • Received:2023-09-28 Online:2024-05-26 Published:2024-05-20

摘要:

为提升高熔融抗冲共聚聚丙烯(IPC⁃J)的刚韧平衡性能,结合抗冲共聚聚丙烯(IPC⁃H)工艺,将IPC⁃J的乙烯含量和乙丙橡胶(EPR)中乙烯含量提高到了12.4 %(质量分数,下同)和54 %。对IPC⁃J、IPC⁃H、IPC⁃1和IPC⁃2等分别进行了分子链段结构和聚集态表征,结果显示,对比IPC⁃H的微观结构,IPC⁃J的EPR含量从19.4 %增至22.8 %,重均分子量(Mw)从2.0×105 g/mol减至1.9×105 g/mol,特性黏度(IV)从1.80 dL/g增到1.86 dL/g,分子量分布指数(MWD)从8.9增至10.7, EPR的最大分子量从1.1×106 g/mol增至1.2×106 g/mol;更多的、相对较长的长乙烯结晶链段有助于改善分散颗粒粒径,占比最大的粒径范围从0.3~0.6 μm升至0.6~0.9 μm;常温和低温冲击强度分别提升至11.0 kJ/m²和5.7 kJ/m²。以300 kt/年聚丙烯生产工艺为基础,在不改变齐格勒⁃纳塔(DQ)型催化剂体系的条件下,通过提高乙烯含量和EPR中乙烯含量实现了高熔融抗冲聚丙烯性能最大优化。

关键词: 抗冲共聚聚丙烯, 冲击强度, 结晶, 连续自成核

Abstract:

To improve the rigidity⁃toughness balance of high⁃impact copolymerized polypropylene with high melt flow rate (IPC⁃J), the ethylene content and the ethylene content in ethylene propylene rubber (EPR) were increased to 12.4 wt% and 54 wt%, respectively, by combination with the high⁃impact copolymerized polypropylene (IPC⁃H) technology. Meanwhile, the molecular segment structures and aggregation morphologies of IPC⁃J, IPC⁃H, IPC⁃1, and IPC⁃2 were investigated. The results indicated that the EPR content of IPC⁃J increased from 19.4 wt% to 22.8 wt%, its weight average molecular weight (Mw) decreased from 2.0×105 to 1.9×105 g/mol, its intrinsic viscosity increased from 1.80 to 1.86 dL/g, its molecular weight distribution index increased from 8.9 to 10.7, and the maximum Mw of EPR increased from 1.1×106 to 1.2×106 g/mol, compared to those of IPC⁃H. The relatively longer ethylene crystalline chains with a greater amount were beneficial to enlarging the dispersed particle size. This resulted in a transformation of the maximum proportion region from 0.3~0.6 to 0.6~0.9 μm, which promoted higher impact strength of 11.0 kJ/m² at 20 ℃ and 5.7 kJ/m² at -20 ℃. The rigidity⁃toughness balance of the IPC with a high melt index were fully optimized through increasing the ethylene content and the ethylene content of EPR, according to the production technology for 300⁃kt/a polypropylene without changing the Ziegler⁃Natta⁃type catalyst system.

Key words: impact copolymer polypropylene, impact strength, crystallization, successive self?nucleation and annealing

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