Effect of Noncrystallizable Components on the Crystallization Kinetics of Polymers
作者:
F. Gornick,
L. Mandelkern,
期刊:
Journal of Applied Physics
(AIP Available online 1962)
卷期:
Volume 33,
issue 3
页码: 907-913
ISSN:0021-8979
年代: 1962
DOI:10.1063/1.1777189
出版商: AIP
数据来源: AIP
摘要:
The effects of chain irregularities, treated as randomly introduced copolymeric units and of added monomeric diluents, on the nucleation rate of crystallizing polymeric systems have been calculated. A marked attenuation in the nucleation rate is expected under certain conditions as a consequence of the varying composition of the melt. The decrease in the nucleation rate becomes more pronounced at the lower undercoolings and as the concentration of the noncrystallizing component increases.The Avrami mathematical formulation for the kinetics of phase changes can be generalized to allow for nucleation and growth rates which vary with the amount of material transformed. The resulting isotherms for copolymers are no longer superposable, superposability being characteristic of crystallization under conditions of constant nucleation and growth. Possible error in the interpretation of crystallization kinetics utilizing the simplified version of Avrami's equation is pointed out, as is the extreme sensitivity of the crystallization process to the presence of small amounts of chain irregularities.
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