Chaiyaporn Pomchaitawat. A study to improve abrasion resistance of natural rubber. Master's Degree(Polymer Science). Mahidol University. Mahidol University Library and Knowledge Center. : Mahidol University, 1993.
A study to improve abrasion resistance of natural rubber
Abstract:
The present work involved studies of the correlations between mechanical properties (tensile, flex fatigue, tear, hardness, and reinforcement) and abrasion properties of natural rubber. The purpose was to establish major factors affecting abrasion property of vulcanised rubbers. Also studied were methods of improvement of abrasion resistance of natural rubber vulcanisates. Two approaches were used, by compounding and by use of diblock copolymer of butadiene and isoprene. For abrasive wear process (i.e. one involving sharp sliding surface under the condition studied) hardness and modulus are important factors determining the wear resistance of carbon black-and silica-filled natural rubber vulcanisates. Elongation at break showed no correlation with abrasive wear of the rubber studied. Contrary to other workers reports, tensile strength, tear strength, flex cracking rate and strain energy show no direct correlation with abrasion resistance but high values of these properties are believed to be desirable for the rubber to exhibit high abrasion resistance. For filled-natural rubber, adhesion between rubber and filler apperars to be very important for the rubber to exhibit high abrasion resistance. Blockcopolymers of butadiene and isoprene of molecular weight among 14000 and 62000 could not help improve the abrasion resistance of unfilled natural rubber/butadiene rubber blends though compatibilisation of the two rubbers as intended. For carbon black-filled natural rubber butadiene rubber blends, blackcopolymers could improve the abrasion resistance to the amount depending on the level of carbon black loaded. For 30 phr the improvement was 30-44% and for 50 phr the improvement was 11-25%. For compounding study of shoe-sole formulation, the type of natural rubber (crepe and TTR5L) and DEG were found to affect abrasion properties.
Mahidol University. Mahidol University Library and Knowledge Center