Fiber from polymer composite of polystyrene and polyhedral oligomeric silsesquioxane

Abstract

Polyhedral oligomeric silsesquioxane (POSS) is an organic-inorganic hybrid compound with an empirical formula of (RSiO1.5)n and various structural formulas possesses a great potential in many applications, especially in the area of polymer composites. Here in this research, random and block copolymers of styrene and heptaisobutyl-(1-propylmethacrylate)-POSS (MAPOSS) or PS-co-PMAPOSS were synthesized. Among all living polymerization routes tested, Concurrent Activator Regenerated by Electron Transfer for Atom Transfer Radical Polymerization and Reversible Addition-Fragmentation Chain Transfer (concurrent ARGET ATRP-RAFT) was the most efficient one that yielded copolymers with controllable molecular weight and polydispersity. Fiber mats of the selected copolymers were then fabricated by electrospinning using mixed solvent of tetrahydrofuran (THF) and dimethylformamide (DMF). For PS, fiber with low diameter distribution could be obtained with mixed solvent of THF/DMF. For PS-r-PMAPOSS, however, an increase of DMF content in the mixed solvent of THF/DMF resulted in porous fibers with rough surface, degree of which also depended upon the MAPOSS content. Poor solubility of MAPOSS phase in DMF seemed to be an origin of these morphological features. Under the same electrospinning condition, fibers from the block copolymer were apparently rougher than that from the random copolymer.