ZnTi layered double hydroxide/dealkaline lignin 2D/2D nanosheets for ultraviolet shielding poly(ethylene terephthalate) nanocomposites

Abstract

Ultraviolet (UV) protection is crucial for enhancing the durability, reliability, and safety of polymeric products. To address this need, a two-dimensional (2D) UV nano-filter was developed by integrating ZnTi layered double hydroxide (ZnTi-LDH) with dealkaline lignin (DL). The ZnTi-LDH/DL nanosheets were then incorporated into a poly(ethylene terephthalate) (PET) matrix using an in-situ polymerization technique. To evaluate its UV shielding performance, the microstructures of the ZnTi-LDH/DL nanosheets and the physicochemical properties of the resulting PET nanocomposites were investigated. The ZnTi-LDH/DL nanosheets retained the intrinsic crystalline structure and 2D morphology of pristine ZnTi-LDH while exhibiting significantly enhanced UV absorption over a broader wavelength range. Incorporating these nanosheets heightened the thermal stability, crystallization behavior, mechanical properties, and UV shielding performance of PET nanocomposites. At a mass fraction of 0.5 % nanosheets, the PET nanocomposite achieved optimal overall performance, exhibiting a Young's modulus of 436.8 MPa, an elongation at break of approximately 580 % and over 90 % blocking efficiency for UVA radiation (400–315 nm). These results indicate the potential of these PET nanocomposites for UV protection applications, particularly in UVA blocking.