共 34 条
The crystallization of blends of different types of polyethylene: The role of crystallization conditions
被引:45
作者:
Galante, MJ
Mandelkern, L
Alamo, RG
机构:
[1] Florida State Univ, Inst Mol Biophys, Dept Chem, Tallahassee, FL 32306 USA
[2] Florida Agr & Mech Univ, Tallahassee, FL 32310 USA
[3] Florida State Univ, Coll Engn, Dept Chem Engn, Tallahassee, FL 32310 USA
来源:
基金:
美国国家科学基金会;
关键词:
blends;
cocrystallization;
models;
D O I:
10.1016/S0032-3861(97)10162-8
中图分类号:
O63 [高分子化学(高聚物)];
学科分类号:
070305 ;
080501 ;
081704 ;
摘要:
Cocrystallization in blends of linear and branched polyethylenes has been studied under both isothermal and slow-cooling crystallization conditions. Before the more common, polydisperse-type polyethylenes were studied and the results analysed, model systems were investigated in detail. The components used in the model binary blends were molecular weight fractions of linear polyethylene, hydrogenated poly(butadiene) as a model for the ethylene-1-alkene copolymers, and a three-arm star hydrogenated poly(butadiene) as a model for the long chain branched polyethylenes. It was found that a key factor in governing the extent of cocrystallization in these blends is the closeness of crystallization rates of each of the components. The extent of the cocrystallization thus diminishes with increasing concentration of the linear component in the blend. It is found that copolymer composition and molecular structure also have a strong influence on cocrystallization. The amount of cocrystallization is favoured at the lowest isothermal crystallization temperatures and is maximized under quenching conditions. The general features that influence cocrystallization, which have evolved from this study, are discussed. (C) 1998 Elsevier Science Ltd. All rights reserved.
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页码:5105 / 5119
页数:15
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