Imparting polyvinyl alcohol enhanced biodegradability, tunable water-solubility, melt processability, and antibacterial activity simultaneously

Polyvinyl alcohol (PVA) is a biodegradable polymer with great potential for sustainable applications. However, its susceptibility to bacterial growth, low biodegradation efficiency, low melt processability, and uncontrollable water solubility limit its wide spreading practical application. Herein, we report a chemical copolymerization strategy to overcome those limitations. Modified PVA (PVA-co-ADMH) was prepared by copolymerizing vinyl acetate (VAc) with the N-halamine monomer 3-allyl-5,5-dimethylhydantoin (ADMH). The biodegradability, thermal properties, antibacterial activity, and water solubility of the synthesized PVA-co-ADMH were evaluated. Composting degradation and soil burial tests showed that, within 30 days, the biodegradation efficiency of PVA-co-ADMH reached 47.1% and 35.4%, respectively, whereas those of pristine PVA were only 15.3% and 5.7%. Enzymatic degradation experiment demonstrated the enhanced biodegradability of PVA-co-ADMH that hydrolytic enzymes can selectively degrade it. Thermal property test indicated that PVA-co-ADMH has a minimum melting temperature of 185.4 °C, endowing it with favorable melt processability. Antibacterial and water solubility tests showed that PVA-co-ADMH exhibited an antibacterial rate of 99.99% after chlorination and could be completely dissolved within 1 min. These results confirm that the copolymerization strategy of VAc with a low proportion of ADMH can improve the biodegradability and water solubility of PVA, while imparting it with antibacterial activity and melt processability.