Characterizing co-continuous high density polyethylene/polystyrene blends

The lack of adequate characterization techniques has been a hindrance to th e effective exploitation and study of co-continuous morphologies in polymer blends. In this paper we prepare co-continuous blends of high density poly ethylene/polystyrene in order to compare Various microstructural characteri zation techniques. The influence of a triblock copolymer interfacial modifi er, hydrogenated styrene-ethylene-butadiene-styrene on the system has also been investigated The surface area and pore dimensions of the blend system after solvent extraction of one of the phases have been measured using the BET nitrogen adsorption technique and mercury porosimetry, respectively. Im age analysis was also carried out as a third source of microstructural info rmation. It is shown that mercury porosimetry can lead to erroneous informa tion while the BET method appears to be both rapid and consistent with SEM observation. The specific surface area of the compatibilized co-continuous blend system is five fold higher than that of its non-compatibilized counte rpart, while the pore diameter of the extracted compatibilized blend is red uced five fold. Using the BET technique, it is possible to generate an emul sification curve in the continuous region, demonstrating the efficacy of th e interfacial modifier in this complex system. (C) 2001 Elsevier Science Lt d. All rights reserved.