摘要
以添加不同比例的茂金属聚乙烯 (mLLDPE) /乙烯 醋酸乙烯酯 (EVA)共混物为研究对象 ,考察了EVA含量对mLLDPE/EVA共混物的力学性能、热性能、流变性能、动态力学性能和形态结构的影响。研究结果表明 ,EVA添加到mLLDPE中 ,增加了mLLDPE的剪切敏感度、降低了mLLDPE的熔融粘度、改善了mLLDPE的流动性和加工性 ;在一定的添加比例范围内mLLDPE和EVA具有很好的相容性 ,可以在改善mLLDPE加工性能、引入极性基团的同时又保持与纯mLLDPE相近的力学性能 ,但会导致共混物材料的刚性下降 ,柔性增加。热分析数据说明 ,mLLDPE/EVA共混体系中 ,在EVA含量较小时共混物存在大量共晶 ,与mLLDPE有很好的相容性 ,无论是熔融曲线还是降温曲线都只出现一个峰。当EVA含量增大时 ,mLLDPE/EVA共混物出现相分离 ,曲线出现双峰 ,但两峰值呈现靠近趋势 。
Two polymer materials, metallocene linear low density polyethylene (mLLDPE) and ethylene/vinyl acetate copolymer (EVA) were used to form binary blends of various compositions. The mechanical properties, morphology, rheological behavior, dynamic mechanical properties and crystallization of mLLDPE/EVA blends were investigated. It was found that with the addition of EVA, the fluidity and processability of mLLDPE were significantly improved, and the introduction of polar groups in this system offered almost the same mechanical properties, only the rigidity decreased slightly. Data of thermal analysis show that,when the contents of EVA are less,there are large number of co-crystals in mLLDPE/EVA blend and EVA has good compatability with mLLDPE.There is only one peak in both the melting curves and cooling curves.Otherwise,phase separation occurred in the blend,and two peaks appeared on the curves,but the two peaks tended to come close,suggesting there are still a few of crystals in the blend.
出处
《中国塑料》
CAS
CSCD
北大核心
2003年第3期25-31,共7页
China Plastics
