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.