Synthesis and characterization of biopolyols through biomass liquefaction of wood shavings and their application in the preparation of polyurethane wood composites

Abstract

AbstractThe sustainability of production systems in wood processing, wood industry, and wooden waste disposal is an important issue for European industry and society. Proper development of products based on renewable wood resources gives an opportunity to provide materials with long-term environmental, social, and economic sustainability. This study aims to establish a new way of forestry and agricultural waste materials utilization by synthesis of bio-based polyols and manufacturing of polyurethane wood composites (PU-WC). The first part of this paper describes the liquefaction of wood shavings at a temperature of 150 °C for 6 h in three different solvents—glycerol, poly (ethylene glycol) and their mixture in a 1:1 ratio. The second part deals with the synthesis of polyurethane (PU) resins containing 90% of biopolyol. Eight sets of materials with different NCO:OH ratios were obtained in a one-step method using a hydraulic press. These materials were characterized, and the material with the most promising properties was selected for polyurethane wood composites production. Composites with 40%, 50%, 60%, and 70% of wood shavings were obtained. The addition of filler caused an increase in flexural strength, Young`s modulus, hardness, and impact strength. Scanning electron microscopy (SEM) showed good adhesion between the polymer and the filler. The optimum filler content is between 50 and 60% by weight of the composite. The presented study provides a significant step toward a greener alternative for materials produced mainly from non-renewable resources.