The birefringence for uniaxially extended DCP-cured natural rubber was measured in the temperature range of 213K-353K. The variation of birefringence reflected the changes of the network structure, i.e. the development and disappearence of strain-induced crystals, and the degree of the orientation of amorphous network chains. It became clear from the variation of birefringence that the nucleation condition which is required to allow growth of an extended chain crystal occurred at extension ratio of 2.5-3.5.
ASJC Scopus subject areas