Soft And Non-Sticky Water-Based PUA Composite for Soft Leather Finishing

Abstract

A soft but non-sticking composite resin, built on waterbased polyurethane (WPU) and polyacrylic resin (PA) with interpenetrating network (IPN) structures was prepared. Specifically, polyacrylic resin emulsions with different cross-linking agents (glycerol methacrylate (GMA), vinyltrimethoxysilane (KH171)) were fabricated first and used as mother liquor, then waterborne polyurethane pre-polymer modified by polydimethylsiloxane (PDMS) to get a hydrophobic surface was dispersed into PA, after post-chain-extension by poly(ether-amine) (D-230) and N-β-(aminoethyl)-γ-aminopropyl methyl dimethoxy silane (KH-602), two kinds of WPU/PA (WPUA) interpenetrating network emulsions were achieved. Thermodynamic compatibility, mechanical properties, anti-sticking performance, and other properties such as glass transition temperature and hydrolysis resistance of WPUAs were investigated in detail. The as-prepared WPUAs exhibits a glass transition temperature close to each other, a wide latex particle size distribution, high light transmittance, and enhanced hydrolysis resistance, indicating the formation of interpenetrating and crosslinking structures between the two components. Benefiting from two polymer chains intertwining and flexible cross-linking, WPUA films exhibited high elasticity (>800%) and low modulus at 100% tension (0.4 MPa), showing desirable flexibility. Under 80°C and 2 kg hot pressing, the leather coating can be easily peeled off, showing excellent anti-sticky properties