CRYSTAL-GROWTH OF INTERMEDIATE-MOLECULAR-MASS POLY(ETHYLENE OXIDE) FRACTIONS FROM THE MELT

被引:78
作者
CHENG, SZD [1 ]
CHEN, JH [1 ]
JANIMAK, JJ [1 ]
机构
[1] UNIV AKRON,COLL POLYMER SCI & POLYMER ENGN,DEPT POLYMER SCI,AKRON,OH 44325
关键词
crystal growth; crystallization; hedrite; intermediate molecular mass; kinetics; morphology; nucleation; poly(ethylene oxide) fraction; regime; spherulite; supercooling; surface free energy;
D O I
10.1016/0032-3861(90)90246-U
中图分类号
O63 [高分子化学(高聚物)];
学科分类号
070305 ; 080501 ; 081704 ;
摘要
Linear crystal growth rates of poly(ethylene oxide) (PEO) fractions crystallized from the melt have been measured in an intermediate-molecular-mass range (MW = 23 000-105 000). Regime phenomena have been observed during crystallization. Regime II/III transitions occur at ΔT = 17.5±0.5 K and regime I/II transitions appear at ΔT = 10±0.5 K for those fractions for which the equilibrium melting temperature of 342.2 K for PEO crystals is used. Interestingly, we have found that in these PEO fractions reversion from regime I back to regime II exists even at a lower supercooling of 8.5±0.5 K. Detailed kinetic analyses of the data demonstrate the suitability of the present nucleation theory. The molecular-mass dependence of the PEO fraction has also been discussed. Morphological changes can be observed along with regime transitions of PEO crystal growth. © 1990.
引用
收藏
页码:1018 / 1024
页数:7
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