以碳纳米管增强相界面的聚丙烯釜内合金材料的设计与制备

In-reactor alloying is an important approach to high performance polypropylene materials. However, the interfacial interaction in polypropylene alloys between the polypropylene matrix and EPR is rather weak, which leads to an unstable phase structure that during melt processing the EPR particles are opt to aggregate forming large size domains which will reduce their toughening effectiveness. This proposal intends to design new polypropylene alloys using "functional nano-supported catalyst" based on reactive carbon nanotubes (CNTs) bearing pendant α-olefin moieties. This approach will take advantage of the one-dimension and high aspect ratio characteristics of CNTs as well as the wrapping polymerization phenomenon which may render CNTs to cross both the PP and EPR phases. With the α-olefin moieties on CNTs being engaged in both the homopolymerization of propylene and copolymerization of ethylene and propylene, CNTs may" stitch " together the PP matrix and EPR dispersing domains, which will suppress the aggregation of EPR particles, leading to the formation of interfacially enhanced polypropylene in-reactor alloys.

釜内合金化是聚丙烯高性能化的重要手段，但由于两相界面作用弱，聚丙烯釜内合金的相结构不稳定，乙丙共聚物橡胶分散相在加工时容易聚集成大尺寸颗粒，降低其增韧效果。如何控制相界面进而控制相结构，是聚丙烯釜内合金研究的挑战。本项目拟通过制备表面带有α-烯烃双键的反应性碳纳米管，进而将其成型并负载Ziegler-Natta 或茂金属催化剂，制备具有可控形态的反应性碳纳米管载体型催化剂，用于丙烯多相共聚；利用碳纳米管的一维特性、高强度、高长径比以及烯烃原位聚合的包覆生长现象，使碳纳米管贯穿聚丙烯和橡胶分散相两相，并利用碳纳米管上的α-烯烃双键分别参与丙烯均聚和乙烯/丙烯共聚，，实现对聚丙烯基体和橡胶分散相的"缝合"，从而抑制橡胶分散相的聚集，制备界面作用增强、相结构稳定的聚丙烯釜内合金材料。

釜内合金化是聚丙烯高性能化的重要手段，但由于两相界面弱，聚丙烯釜内合金的相结构不稳定，乙丙共聚物橡胶分散相在加工时容易聚集成大尺寸颗粒，降低其增韧效果。如何控制相界面进而控制相结构，是聚丙烯釜内合金研究的挑战。本项目通过制备表面带有α-烯烃双键的反应性碳纳米管，进而将其成型并负载Ziegler-Natta催化剂，制备了具有可控形态的反应性碳纳米管载体型催化剂，用于丙烯多相共聚，从而利用碳纳米管的一维特性、高强度、高长径比以及烯烃原位聚合的包覆生长作用，使碳纳米管贯穿聚丙烯和橡胶分散相两相，利用碳纳米管上的α-烯烃双键分别参与丙烯均聚和乙烯/丙烯共聚，实现对聚丙烯基体和橡胶分散相的缝合，达到抑制橡胶分散相的聚集，制备出界面作用增强、相结构稳定的聚丙烯釜内合金材料。在此基础上，将橡胶分散相进一步拓展为极性聚合物分散相，基于同一概念，实现了相形态精确可控的聚烯烃/极性聚合物纳米合金的制备。