Liquefaction of waste pine wood and its application in the synthesis of a flame retardant polyurethane foam

The utilization of sustainable forestry waste resources in the production of polyurethane (PU) foam is a promising green alternative to the use of un-sustainable resources. In this work, we report the liquefaction of waste pine wood at different reaction temperatures and its application in synthesizing a melamine phosphate modified wood type polyurethane foam (designated as MWPU). Our strategy was to obtain liquefied pine-based polyol at an optimum reaction temperature and apply the polyol in synthesizing a flame retardant (MWPU) foam via the incorporation of a melamine phosphate (MP) filler. Spectroscopic and microscopic analyses were conducted to investigate the structure characteristics and the morphology of the liquefied waste pine wood polyol and the synthesized (MWPU) foam. An optimum liquefaction temperature of 160 degrees C was obtained and the glass transition temperature (T-g) for 10 wt% incorporated MP foam was 43.8 degrees C. The as-prepared (MWPU) foam showed higher glass transition temperature and storage modulus than pine wood based PU foam without MP. The MWPU foam withstood heating at 300 degrees C without significant degradation and also exhibited a higher thermal stability and limited oxygen index (LOI) value than pine wood based PU foam. These results provided an insight into the physical and structural properties of the as-prepared bio-based foam and paved the way toward preparing bio-based PU foam, which could further expand its potential applications.