Reclaiming of rubber by a renewable resource material (RRM). III. Evaluation of properties of NR reclaim

Sulfur-cured filled natural rubber (NR) is successfully reclaimed by using a renewable resource material (RRM) and diallyl disulfide (DADS), which is the major constituent of RRM. Reclaiming of NR vulcanizate was carried out at 60 degrees C for 35 min in an open two-roll mixing mill. Evaluation of t he properties of NR reclaim was carried out by mixing it with virgin rubber in various proportions. The cure characteristics and mechanical properties of the virgin NR/ reclaim NR blend were studied, With increase in the prop ortion of reclaim rubber (RR) in virgin NR/ reclaim NR blend scorch time an d optimum cure time decrease. To increase scorch time N-cyclohexylthiophtha limide as prevulcanization inhibitor (PVI) was added in NR/RR (50/50) blend . It was found that use of 40% NR reclaim with virgin rubber resulted 83% r etention of tensile strength of that of the virgin NR vulcanizate. Effect o f carbon black loading was studied in NR/RR (50/50) blends. Tensile propert ies and swelling value of different NR/RR blends were evaluated before and after aging. (C) 2000 John Wiley & Sons, Inc.