摘要
用高效球形Ziegler-Natta催化剂,通过多段气相聚合的方法制备了一系列聚乙烯-聚丙烯-无规乙丙共聚物(PE-PP-EPR)原位合金。该原位合金为粒径大且分布窄、流动性好、形貌好的球形颗粒,兼具很好的抗冲强度(不小于80.4kJ/m2)和很高的弯曲模量(不小于1.1139GPa),所设计的4段聚合工艺(丙烯预聚、乙烯均聚、丙烯均聚和乙丙共聚)能在较宽的范围内调节PE-PP-EPR原位合金的组成及其分布。实验发现,PE-PP-EPR原位合金的组成及其分布受乙烯和丙烯混合气压力以及乙烯和丙烯混合气组成的影响较大。合金的机械性能与合金的组成及其分布密切相关,而合金的组成及其分布直接受聚合条件的控制,所以聚合条件对合金的机械性能影响很大。
A series of PE-PP-EPR in situ alloys were synthesized by sequential four-stage gas-phase polymerization (propylene prepolymerization, ethylene homopolymerization, propylene homopolymerization and ethylene-propylene copolymerization) on high efficiency spherical Ziegler-Natta catalyst. PE-PP-EPR in -situ alloys were spherical granules with good flowability and showed both high impact strength ( greater than or equal 80.4 kJ/m2) and high flexural modulus ( greater than or equal 1.1139 GPa). Effect of reaction conditions at the fourth stage (such as ethylene content in ethylene-propylene feed mixture and pressures of gas mixture of ethylene and propylene) on compositions and mechanical properties of PE-PP-EPR in-situ alloys were studied. Both composition of PE-PP-EPR and its distribution of in-situ alloys could be regulated in relatively wide range. Reaction conditions at the fourth stage could affect mechanical properties of PE-PP-EPR in-situ alloys effectively.
出处
《石油化工》
EI
CAS
CSCD
北大核心
2005年第4期376-379,共4页
Petrochemical Technology
基金
国家重点基础研究发展规划项目(G1999064803)
国家自然科学基金资助课题(G20274037)。
