纳米尺寸马来酸酐共聚微球作为尼龙6/线性低密度聚乙烯体系增容剂的研究

用电荷转移络合物(CTC)自稳定沉淀聚合法合成出纳米尺寸马来酸酐-醋酸乙烯酯交联型共聚物微球,直径大约在150 nm左右.将少量这种新型纳米级共聚物微球添充到尼龙6(PA6)/线性低密度聚乙烯(LLDPE)体系中；发现纳米级微球颗粒的二乙烯基苯的双键以及酸酐基团分别能与两相发生化学反应,在尼龙6/聚乙烯体系中微球大部分出现在两相界面处,分析表明这些界面处的纳米级微球颗粒能够有效降低球状聚乙烯分散相的尺寸,使分散相粒径稳定在一个较小值(接近1μm),起到类似“分散相稳定剂”的作用.纳米级共聚物微球含量在1.75％左右时,各项性能得到较明显的提升.在拉伸强度与杨氏模量降低10％左右的情况下,冲击强度提高1.35倍,吸水百分率从纯尼龙64.9％下降到最小只有1.2％左右.对其增韧机理进行了初步探讨.

STUDY ON THE COMPATIBILITY OF PA6/LLDPE/NANO-SIZED COPOLYMER MICROSPHERES COMPOSITES

Crosslinked maleic anhydride-vinyl acetate copolymer microspheres were synthesized by charge transfer complexes(CTC) self-stable precipitation polymerization with mean diameter of about 150 nm.Afterwards,copolymer microspheres/poly(ethylene) composites(CM/LLDPE) with low CM contents were used as pre-dispersed composites and melt-mixed with nylon6(PA6) resin to prepare a series of PA6/LLDPE/CM composites with low CM contents.It was found that the divinylbenzene's double bond groups and poly(ethylene),anhydride groups and nylon6 produced chemical reaction on phase interface respectively.According to the SEM analyses,it was found that the effect of various amounts of copolymer microspheres on the morphological structure and size of dispersed phase was obvious.It can effectively reduce the size of dispersed phase to fill the copolymer microspheres;on the surface of poly(ethylene) dispersed phase,the nano-sized microspheres played the role of a dispersed phase stabilizer,and this was similar to the emulsifier in emulsion polymerizationin.When the nano-sized microspheres content reached about 1.75%,the performance of composites was improved obviously:the impact strength of composites was increased by 1.35 times compared to pure nylon 6,although the tensile strength and Young's modulus of composites were reduced by about 10%.The water absorption percentage droped to 1.2% compared to 4.9% of pure nylon 6.The toughening mechanism was also discussed in this paper;it was a new and important method to compatibilize two phase by stabilizing the size of dispersed phase.