A novel nanosilica‐supported ultraviolet absorber for the preparation of robust biodegradable plastic film with high ultraviolet aging resistance

A novel type of nanosilica‐supported ultraviolet absorber (SiO₂‐N‐0) was successfully prepared by chemically grafting 2,4‐dihydroxybenzophenone (UV‐0) onto the surface of nanosilica (SiO₂) with the aid of a coupling agent via a sol–gel method, which was confirmed by Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy, and thermogravimetric analysis. SiO₂‐N‐0 was then incorporated into poly(butylene adipate‐co‐terephthalate) (PBAT) to fabricate biodegradable composite film with a casting method. As expected, SiO₂‐N‐0 was homogeneously dispersed in PBAT matrix, leading to higher mechanical strength and lower water vapor transmission of PBAT/SiO₂‐N‐0 film than those of PBAT/SiO₂/UV‐0 film. More importantly, because of its low migration and volatility, SiO₂‐N‐0 endowed PBAT film with excellent aging resistance under ultraviolet radiation than did the corresponding low molecular ultraviolet absorber UV‐0. Taken together, these results suggest that thus prepared PBAT/SiO₂‐N‐0 composite film may find many applications, especially as biodegradable agricultural mulch film. POLYM. COMPOS., 40:4154–4161, 2019. © 2019 Society of Plastics Engineers