STYRENE-BUTADIENE POLYTELOMERS FOR PRESSURE-SENSITIVE APPLICATIONS

Novel styrene-butadiene polymer latex compositions and their utility f or pressure-sensitive and other adhesive applications are described. T hese compositions, termed polytelomers, are based on the concept of sy nthesising sequentially a low glass transition temperature, high molec ular weight (polymeric) fraction, followed by a high glass transition, low molecular weight (telomeric) fraction, in an attempt to simulate the compounding of elastomeric adhesives. Some of the described compos itions can exhibit multiphase morphology, having discrete styrene-rich domains surrounded by butadiene rich phase, both of these phases bein g embedded in a ''honeycomb'' carboxyl-rich phase. The compositions we re characterized by dynamic mechanical spectroscopy and by electron tr ansmission microscopy, as well as by molecular weight distribution and glass transition temperature range data. Examples of adhesive applica tions are also given.