ISSN:
0022-3832
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The effect of time and temperature on the crystalline recovery of quenched Marlex 50 polyethylene has been investigated. Quenching thin films in ice water reduced the room temperature crystallinity from a normal value of 93 to 82%. These specimens were maintained at 25, 66.2, and 106.4°C., and the time variation of crystallinity was followed by nuclear spin resonance. The crystalline recovery appears to follow the empirical formula, X = A + B log t, where X is the percentage crystallinity and t, is the time in hours. The rate, X, increases with temperature. The temperature-dependence of B was computed by assuming the rate to be controlled by diffusion in the amorphous phase. The temperature-dependence of diffusion is determined by nuclear spin resonance line width measurements to be exp {-8700/RT}. The rate is then X = C/t exp {-8700/RT}, and C, evaluated at 25, 66.2, and 106.4°C., is 2.2 ± 1.9, 1.7 ± 0.5, and 2.1 ±0.2 × 105. This agreement is within the probable error, and justifies the assumption of diffusion as the rate-controlling factor. The result is X = 2.04 × 105(1/t) exp { -8700/RT} and X = A + 4.70 × 105 log t exp {-8700/RT}.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1958.1202711506
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