SELF-ADHESION OF NATURAL-RUBBER MODIFIED WITH PHOSPHORYLATED CASHEW NUT SHELL LIQUID

The self-adhesion strength of natural rubber (NR) compounds modified w ith phosphorylated cashew nut shell liquid (PCNSL) prepolymer has been studied with respect to variations in contact time, contact pressure, storage time, and concentration of PCNSL. The self-adhesion strength of NR as measured from the 180 degrees peel test showed a maximum at 1 0 phr of PCNSL. The adhesion between substrates containing various con centrations of PCNSL (from 0 to 20 phr) also reached a maximum at a PC NSL concentration of 10 phr in one of the substrates. An increase in s elf-adhesion strength with storage time was observed for the PCNSL-mod ified NR compounds, which is presumed to be due to the time-dependent interfacial diffusion.