A straightforward synthesis and characterization of a new poly(imide siloxane)-based thermoplastic elastomer

Three series of poly(imide siloxane) (PIS) copolymers were synthesized through straightforward simultaneous condensation reaction of pyromellitic dianhydride (PMDA), 2, 2'-bis[4-(3-aminophenoxy)phenyl] sulfone (m-BAPS) and three different number-average molecular weights (M-n = 859, 1152 and 1619 g.mol(-1)) of alpha, omega-bis (3-aminopropyl) polydimethyl siloxane (APPS). The effects of hard segment, polyimide (PI), on the properties of PIS copolymers were investigated. The prepared PIS copolymers possess the properties of thermal plastic elastomers. Microphase separation, affected by formulation, was found to be important phenomenon that determined the physical properties of the PIS copolymer. Mechanical measurement with the Instron-type tensile meter showed that the copolymers have elongation at break of up to 324%. Two prepared samples (APPS M-n = 859, PI content of 15 and 20 wt %) were found to exhibit good rubber property of being able to retract to original length upon release of the stress applied, others were characterized as plastics. The softening temperatures of the PIS thermoplastic elastomers ranged from 109 to 265 degrees C, and can easily be processed by extrusion or injection molding, and recycled.