Analysis of variation of molecular parameters of natural rubber during vulcanization in conformational tube model. II. Influence of sulfur/accelerator ratio

A natural rubber (NR) with a conventional sulfur cure system and a ratio of sulfur/accelerator (Omega) equal to 3 was investigated. The network struct ure of the NR during vulcanization was analyzed using a model of rubber ela sticity based on the tube concept, which was applied to the treatment of th e stress-strain measurements. The influence of cure time and temperature on the chemical crosslinks density was analyzed. The values were compared wit h those obtained by means of an equilibrium volume swelling measurement. Th e differences between samples of NR cured with Omega = 3 and 1.5 were analy zed. (C) 1999 John Wiley & Sons, Inc.