Flame‐resistant and tough polyvinyl alcohol film with ultraviolet‐absorbing capacity

Abstract

Fireproofing the polyvinyl alcohol (PVA) membrane is an essential and urgent reinforcement to ease the restriction in flame-resistant requirements. The traditional method by the physical and heterogenous introduction of a large number of metal hydroxides, halogenated and organic compounds efficiently enhance the flame-retardancy but severely weakens the biocompatibility, mechanical strength, and transparency of PVA membranes. In this work, two bio-extracted compounds, phytic acid (PA) and creatine (CR) are employed to construct a fireproof, tough and transparent PVA membrane. The LOI of the PVA/PACR membrane increases from 18% to 30% and reaches a V-0 grade in UL-94 testing. Meanwhile, the mechanical strength receives 20% reinforcement due to a chemical crosslinking between PVA, PA, and CR. Intriguingly, unsaturated chemical bonds from PA and CR endow a favorable UV-absorbing capacity to the PVA membrane, which will benefit the anti-aging and food freshness retaining demands in advanced packaging applications.