Mechanical and UV protection performances of polylactic acid spunlace nonwoven fabrics coated by eco-friendly lignin/water-borne polyurethane composite coatings

Abstract

Lignin as a biopolymer, has drawn much attention owing to its renewable nature, biodegradability, easy availability, and excellent stability. Water-borne polyurethane (WPU)-based coatings have been contributing to sustainable and eco-friendly practices offer a straightforward avenue for the value-added utilization of lignin. With the alarming rise in death rates attributed to skin diseases due to ultraviolet (UV) radiation damage, researchers have been actively searching for sustainable coating processes that enhance the UV protective capabilities of fabrics. In this paper, a facile strategy was reported for fabricating an environment friendly, mechanically durable, and UV protective biodegradable polylactic acid (PLA) spunlace nonwoven fabrics (SNFs) using lignin/WPU composite coatings. Lignin/WPU coating pastes were prepared using five different recipes including different lignin concentrations (0.5, 1.0, 1.5, and 2.0 wt.%) and coated on PLA SNFs via an applicator and thermally cured. Mechanical properties (e.g. tensile strength and abrasion resistance) and UV protection factor (UPF) values of fabrics were investigated. The coating films were characterized by Fourier Transform-Infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) analysis. Lignin/WPU coated SNFs showed excellent UV protection performance and UPF values were obtained above 100 for all formulations. Lignin/WPU coatings provided an improving effect on the tensile strength and abrasion resistance performances of coated SNFs compared to uncoated SNFs. This work provides a simple and efficient strategy for preparing environmentally friendly lignin/WPU coatings, which are promising for application in the textile industry.