USE OF NATURAL-RUBBER PROPHYLACTICS WASTE AS A POTENTIAL FILLER IN STYRENE-BUTADIENE RUBBER COMPOUNDS

Owing to the unstable nature of the latex compound and the strict spec ifications in the quality of latex products such as condoms and examin ation gloves, the rejection in the latex industry comes to about 10 to 15% of the rubber consumed. These latex rejects contain about 95% rub ber hydrocarbon of very high quality. A cost-effective technique has b een developed for the reuse of natural rubber (NR) prophylactics waste in styrene-butadiene rubber (SBR). The influence of powdered latex re jects on the curing characteristics, mechanical properties, acid failu re behavior of SBR has been investigated. More emphasis is placed on t he effect of both particle size and the loading of latex waste filler. Swelling studies were carried out to establish the degree of crosslin king of SBR and to assess the extent of interaction between the matrix and latex waste filler of varying particle sizes. A three layer model has been set up to study the diffusion of sulfur from the matrix phas e to the filler phase. Scanning electron microscopy has been used to a nalyze the particle morphology, filler dispersion, and filler-matrix i nterface adhesion. The results of the study revealed that NR prophylac tics rejects can be used effectively as a potential filler in SBR up t o about 40 phr loading. (C) 1996 John Wiley & Sons, Inc.