STRESS-RELAXATION CHARACTERISTICS OF NATURAL-RUBBER MODIFIED WITH PHOSPHORYLATED CASHEW NUT SHELL LIQUID PREPOLYMER

The tensile stress-relaxation characteristics at room temperature of g um NR vulcanizates containing 10-20 phr of phosphorylated cashew nut s hell liquid (PCNSL) prepolymer were studied at various strain rates an d strain levels, in comparison with that containing the same dosage of a-ethyl hexyl diphenyl phosphate and the unmodified sample. Modificat ion of NR with 10-15 phr of PCNSL resulted in improvements in tensile properties along with a lower degree of stress relaxation at the highe r strain rates and strain levels. (C) 1997 John Wiley & Sons, Inc.