Lignin–Poly(vinyl alcohol) Compound from Acetalization Synthesis as a Reinforcing Filler for High-Performance Gel-Spun Fibers

Abstract

As a natural macromolecular material, lignin (L) can be used as a filler to enhance the mechanical properties of poly (vinyl alcohol) (PVA). However, the blending system of L/PVA suffers from the poor compatibility of hydrophobic lignin and hydrophilic PVA. To address this issue, lignin was combined with PVA by acetalization synthesis at different reaction conditions. The obtained lignin–PVA (L–P) compounds were incorporated into 5% L/PVA gel-spun fibers as a second filler to enhance the filler/matrix compatibility. 5% L/PVA fiber reinforced by 5% L–P compound obtained with L/PVA mass ratio of 1:2, reaction temperature of 150 ℃, and reaction time 12 h exhibits the best mechanical properties. The optimal tensile strength is 925.23 MPa, Young’s modulus is 26.89 GPa, and toughness is 16.45 J/g. This work offers promising approach in developing compatible lignin/synthetic polymer systems for more sustainable high-performance fibers in the industrial or technical textile field.