Biobased Ultralow-Density\nPolyurethane Foams with\nEnhanced Recyclability

Abstract

Polyurethane (PUR) foams are widely used in many engineering\napplications,\nbut their efficient recycling has remained a major challenge for many\nyears. This study presents a novel strategy of incorporating hydrolyzable\nester units into the PUR structure to enhance PUR foam recyclability.\nThe present eco-design concept of PUR materials enables fully the\nreplacement of petrochemical polyols with biobased alternatives and\nproduction of ultralow-density (16 kg·m^–3)\nPUR foams. To reach this target, a series of low-function polyols\nbased on succinic acid (SA) were first synthesized. Their subsequent\nuse in combination with a high-functional biobased tall oil-derived\npolyol led to the production of highly homogenous semirigid, partly\nopen-cell PUR foams with outstanding structural, thermal, and mechanical\nproperties. Additionally, the study shows that the incorporation of\nSA-polyols with hydrolyzable ester linkages into the PUR foams significantly\nenhances their recyclability via glycolysis, proving their potential\nin contributing to a circular economy and addressing plastic waste\nconcerns.