Crystallization of Unvulcanized Rubber at Different Temperatures
| Autor: | Lawrence A. Wood, Norman Bekkedahl |
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| Rok vydání: | 1946 |
| Předmět: | |
| Zdroj: | Journal of Applied Physics. 17:362-375 |
| ISSN: | 1089-7550 0021-8979 |
| DOI: | 10.1063/1.1707725 |
| Popis: | Crystals may be formed in natural rubber under varied experimental conditions. Different combinations of stretching and cooling have been used to induce crystallization in unvulcanized and in vulcanized rubber. The appearance and disappearance of crystals have been studied by observations of the volume, heat capacity, light absorption, birefringence, x-ray diffraction, hardness, and other mechanical properties. There has, however, been no comprehensive study of the effect of temperature on the crystallization. The present investigation was undertaken to explore this field. In the work reported here it has been the aim to study crystallization at different temperatures under the simplest possible conditions. The main features of the crystallization of vulcanized rubber have been shown to be similar to those of the crystallization of unvulcanized rubber, vulcanization decreasing the rate of crystallization. Consequently unvulcanized rubber was selected for study. Stretching obviously complicates the experimental conditions, and so was not employed. Of the different methods of measuring crystallization, it seems that change of volume is the simplest and best adapted to yielding quantitative data on the course of the crystallization or fusion. The present work is, therefore, concerned with a general study of the volume changes in unvulcanized rubber at different temperatures. |
| Databáze: | OpenAIRE |
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