ＮＲ，ＩＲのミクロ構造と物性に関する研究 （第１報） 延伸ディラトメトリーによるゴムの伸長結晶性測定と物性

Abstract

The crystallinity of polyisoprene elastomers including natural rubber on stretching was measured using a diratometer designed for streched samples. It was found that a polyisoprene of 90% cis 1, 4 content showed much less crystallization on stretchig than did natural rubber or higher cis 1, 4 content polyisoprene at 5 to 15°C. The onset of the steep increase in stress was found to start at a higher strain as the cis 1, 4 content decreased. The repulsion property of stretched rubbers was improved, especially at low temperatures for low cis 1, 4 content rubber. This result implies increased flight distance of golf balls made of lower cis 1, 4 polyisoprene. Generally, the crystallinity of an elastomer on stretching is measured using an X-ray diffractometer. The diratometric method used in this work offers (1) simple, low cost apparatus (2) easy temperature variation (3) information on the interaction between a filler and an elastomer.