| Abstract: | The tack of uncrosslinked gum and filled brominated isobutylene-co-p-methylstyrene (BIMS) was examined as a function of time using the 180° peel geometry. The tack strength showed a 1/4th power dependence with respect to time. The BIMS showed marginally lower tack strength than its non-brominated precursor (IMS). The addition of fillers to the BIMS increased the tack strength as compared to the gum rubber. With increasing filler loading, the tack strength increased up to a certain contact time. A good adhesion between BIMS and ethylene propylene diene terpolymer elastomer (EPDM) was observed due to their similar solubility parameters, whereas adhesion between BIMS and natural rubber (NR) was low. Autohesion studies of different blends of BIMS with EPDM and NR revealed that 70 : 30 BIMS : EPDM and 30 : 70 BIMS : NR blends showed higher tack strength than their constituent polymers. The results could be explained in terms of green strength and compression creep measurements. |
