Synthesis of poly(maleic anhydride-co-vinyl chloride) crosslinked microspheres and its superior enhancement in mechanical strength and antibacterial activity for poly(vinyl alcohol) composite films

Abstract

Poly(vinyl alcohol) (PVA) is an attractive raw material and widely applicated in multiple fields owing to its unique features. However, the poor mechanical strength and without intrinsic antimicrobial activity severely restrained its further use. Herein, we proposed a novel strategy to fabricate PVA-based composites film with excellent mechanical properties and superior antibacterial activity by employing functional polymeric microspheres as a hydrogen bonding cross-linker and bactericide loading platform. Firstly, we synthesized poly(maleic anhydride-co-vinyl chloride) cross-linked microspheres (PDVM) via self-stabilized precipitation polymerization and subsequently the PDVM microspheres were reacted with gaseous ammonia to endow the microsphere surface with abundant carboxyl and amidogen group. As a result, uniform PDVM microspheres with diameters ranging from 175 to 685 nm and controlled gel content (25.3–91.8%) were prepared successfully and aminolyzed PDVM microsphere (NPDVM) were obtained. By incorporating 5 wt% NPDVM in PVA matrix, the composite film has a significant increment in tensile strength (63.9 MPa) and elongation at break (107 %) in comparison to neat PVA (51.8 MPa, 80%) mainly attributed to the formation of multiple hydrogen bonding network. Furthermore, by immobilizing Zn2+ on the surface of NPDVM/PVA film via complexation, the composite film exhibited outstanding antibacterial efficiency against E. coli and S. aureus.