Lab-scale structural insulated panels with lignin-incorporated rigid polyurethane foams as core
Lab-sca e structura insu ated pane s (SIPs), using ignin-incorporated rigid po yurethane (RPU) foams as the therma insu ation core, were fabricated and characterized. The RPU foams incorporating surface-modifed ignin were sandwiched between two oriented strand board (OSB) sheets to produce ignin-incorporated SIPs with nomina dimensions of 350×350×46mm3. In comparison to the reference RPU foam without ignin, the ignin-incorporated RPU foams exhibited progressive y higher therma stabi ities coinciding with ignin amount, but simi ar therma conductivity (˜24.5mW·m−1 K−1) and water absorption (˜0.018 g/cm3). The bonding, shear, and fexura strength of ignin-incorporated SIPs were 150–210 kPa, 110–150 kPa, and 3–4 MPa, respective y, which were simi ar to that of reference (no ignin contro ) SIP. Lignin-incorporated RPU foams and SIPs with 5%–15% ignin addition amount exhibit better performance than the reference RPU foam and SIP. We attribute overa enhancements in therma and mechanica properties of the ignin-incorporated RPU foams, and the corresponding SIPs, to the surface-modifed ignin, serving as a reactive cross inker with ample chemical interaction to polyisocyanates during the formation of RPU foams.