Liquefaction of Bamboo Powder as the Source of Renewable and Sustainable Polyols for Waterborne Polyurethane Leather Coatings

Abstract

Leather products usually undergo special finishing treatments to protect them from damage and mask any imperfections in their appearance, guaranteeing a polished and premium-quality outcome. Green coating materials are in urgent need with ever increasing environmental protection consciousness. The resins used to produce leather coatings are required to be derived as much as possible from bio-based materials. Addressing this challenge necessitates the creation of a novel bio-based coating that boasts excellent water resistance, adhesion, and mechanical strength. This research focused on developing polyols from bamboo powder, concurrently synthesizing a range of bamboo powder-based waterborne polyurethanes (BWPU) using isophorone diisocyanate (IPDI) and polytetramethylene glycol (PTMG2000) as the key monomers. The results revealed a remarkable improvement in water resistance, adhesion, and mechanical strength with an increase in the bamboo powder polyols concentration. Notably, the film demonstrated the most optimal overall properties when the bamboo powder polyol content was 4 wt%. Specifically, the BWPU4 film exhibited a water absorption rate of 6.13%, a tensile strength of 16.34 MPa, and a significant increase in adhesion force, reaching 43.6 N/cm. This innovative approach was expected to present new avenues for the leather industry to embrace renewable resources and minimize its environmental impact