Flow-induced crystallization of propylene/ethylene random copolymers
Flow-induced crystallization of propylene/ethylene random copolymers
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DOI：
10.1007/s10973-009-0532-3
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发表时间：
2009-12-01
影响因子：
4.4
通讯作者：
Meijer, Han E. H.
中科院分区：
文献类型：
--
作者：
Housmans, Jan-Willem;Peters, Gerrit W. M.;Meijer, Han E. H.
采用DSC和流变仪研究了共聚单体含量和工艺条件对丙烯/乙烯（P/E）无规共聚物结晶动力学的影响。与纯聚丙烯相比，乙烯的存在降低了熔融和结晶温度，并且静态结晶速率Chi在相等的标称过冷度下增加，因为晶体生长速率G和核数N都增加。流动对结晶动力学的影响随乙烯含量的增加而减小。尽管如此，观察到不同的制度的流动诱导结晶，但它们的大小和它们之间的过渡的位置取决于乙烯含量，并可以表示在分子取向，分子拉伸，和结晶能力的系统的水平。
The influence of the co-monomer content and processing conditions on the crystallization kinetics of propylene/ethylene (P/E) random copolymers is studied using DSC and rheometry. The presence of ethylene lowers the melting and crystallization temperature compared to pure polypropylene, and the quiescent crystallization rate, Chi increases at equal nominal undercooling, because both the crystal growth rate, G, and number of nuclei, N, increases. The effect of flow on the kinetics of crystallization decreases with the ethylene content. Still, different regimes of flow-induced crystallization are observed, but their size and the position of the transitions between them depend on the ethylene content, and can be expressed in terms of the level of molecular orientation, molecular stretch, and crystallization capacity of the system.