QUANTUN CHEMICAL STUDIES ON DELAYED-ACTION VULCANIZATION ACCELERATORS FOR RUBBER

Vulcanization and the Properties of Rubber

Rubber is composed of long stringlike polymer molecules, which are pinned together at random points by crosslinks. As the density of crosslinks is increased, the molecules get localized and the system undergoes a phase transition from a liquid to an amorphous solid state. The elastic properties of the resulting solid are very different from those of metals, and are primarily due to changes in t...

From Vulcanization to Isotropic and Nematic Rubber Elasticity

– A Landau theory is constructed for the vulcanization transition in cross-linked polymer systems with spontaneous nematic ordering. The neo-classical theory of the elasticity of nematic elastomers is derived via the minimization of this Landau free energy; this neoclassical theory contains the classical theory of rubber elasticity as its isotropic limit. Our work not only reveals the statistic...

Effect of Rubber Nanoparticle Agglomeration on Properties of Thermoplastic Vulcanizates during Dynamic Vulcanization

We previously reported that the dispersed rubber microparticles in ethylene-propylenediene monomer (EPDM)/polypropylene (PP) thermoplastic vulcanizates (TPVs) are actually agglomerates of rubber nanoparticles. In this study, based on this new understanding of the microstructure of TPV, we further revealed the microstructure-properties relationship of EPDM/PP TPV during dynamic vulcanization, es...

Occupational Dermatitis Caused by Vulcanization Accelerator of Gloves

Three cases of occupational dermatitis due to additives to rubber gloves are discussed. These cases were not a result of latex allergy and their dermatitis caused by vulcanization accelerator in rubber gloves. Most people have heard of latex allergy, and some people avoid the use of latex products. However, some rubber-related contact dermatitis of hands is caused by additives such as vulcaniza...

Analysis of husking action in the rubber-roll rice sheller