Thermal conductivity of styrene butadiene rubber compounds with natural rubber prophylactics waste as filler

Efforts on a large scale have been made by the polymer industry to develop cost effective techniques to convert waste and used rubber into processable forms. Some of the authors have developed a cost effective technique for t he reuse of natural rubber (NR) latex condom waste as a potential filler in styrene butadine rubber (SBR). It has been proved that waste NR particles do reinforce SBR matrix. For optimizing cryosystem performance of the blend s, characterization of the composites in terms of thermal behaviour is impo rtant. Thermal conductivity of SBR filled with lightly cross-linked NR late x waste is measured using the transient plane source (TPS) method in the te mperature range of 100-300 K, It has been found that the thermal conductivi ty of SBR composites increases linearly with temperature to a peak value at a temperature which lies well within the glass transition region of SBR. W ith further increase of temperature the thermal conductivity decreases asym ptotically to a constant value near 300 K. The variation in the thermal con ductivity is empirically correlated with the present experimental data by t he equation, lambda(T) = a + bT + cT(2), where a, b and c are parameters wh ich are polymer dependent and have different values below and above the gla ss transition. The observed variation in thermal conductivity is explained on the basis of various phonon scattering mechanisms, namely structure scat tering and cooperative motion of repeat units, as also by considering struc tural features and the effect of temperature on structural units in a pheno menological manner. (C) 1999 Elsevier Science Ltd. All rights reserved.