A novel strategy for manufacturing multifunctional carboxymethyl cellulose-based film: Integrated flame retardancy, UV resistance, and hydrophobicity

In this research, a novel strategy was developed to fabricate multifunctional carboxymethyl cellulose (CMC)-based films endowed with flame retardancy, UV resistance, and hydrophobicity. Phenylphosphonic acid (PPOA) and urea were employed as phosphorus and nitrogen group introducing agents, tea polyphenol (TP) and lignin served as char layer enhancers and multifunctional enhancers. The successful synthesis of the CMC-Lignin-PPOA-TP-urea composite (CMC-PUTP/L) was verified by scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The obtained CMC-PUTP/L film exhibited significant flame retardancy with a limiting oxygen index (LOI) of 35.2 % and UL-94 V0 rating, a reduction in peak heat release rate (PHRR) and total heat release (THR) by 57.37 % and 23.16 %, respectively. In addition, the film demonstrated a high ultraviolet protection factor (UPF) of 904.3 and a water contact angle of 109.8°, confirming its sufficient UV-blocking performance and hydrophobicity. It is obvious that the established approach may support a potential strategy, for overcoming the endogenous defect of CMC- even biomass-based films with flame retardancy, UV resistance, and hydrophobicity, to satisfy the requirements in various application scenarios.