Applicable Base Polymer Properties
Styrene block copolymers (SBCs) offer cohesion, strength, and heat resistance for both pressures sensitive adhesives (PSAs) and non-pressure sensitive adhesives. The styrene phase forms a physically crosslinked network in the adhesive at room temperature. Crosslinking via UV or EB radiation will provide even greater heat resistance.
Of the SBCs, styrene isoprene styrene (SIS) is most often used in hot melt PSAs. SIS polymers are generally preferred over styrene-butadiene-styrene (SBS) polymers for hot melt adhesives because the SIS polymers provide a higher level of tack and are less likely to form gels during processing.