Study Of Biomass-based Non-isocyanate Polyurethanes

Polyurethanes(PU)is a wild applied composite material with numerous applications.In contrast to the conventional PU materials preparation that based on the toxic isocyanates,non-isocyanate polyurethanes(NIPUs)materials possessed obvious advantages,which becoming a hotspots in recent years.Among the existing routes for NIPU preparation,the cross-linking of cyclic carbonates with polyamines is considered to be the most environmentally friendly way,which can be extend to the adoption of biomass derived precursor so that allowed renewability.In basic routes,the biomass derived polyols were under goes oxpropylylation,cyclic carbonation,and finally reacted with the polyamines.Therefore,this study focuses on the usage of three kind of biomass polyols as the substrate for the NIPU materials.After chemical modification of the functional groups(hydroxyl or unsaturated double bonds)and preparing the epoxy resins and cyclic carbonates.The biomass-based cyclic carbonate is cross-linked with polyamines to prepare different types of NIPU materials for various applications.(1)The lignin oil was isolated from poplar wood by reductive catalytic fractionation(RCF),and the hydroxyl groups in the reduced lignin molecules were epoxidised and carbonated,and the cyclic carbonate was cross-linked with polyamines to produce NIPU.The obtained NIPU film possessed tensile strength of 12.5 MPa,and the film exhibited certain antibacterial and UV resistance properties.(2)The sweet potato residues from starch industry was liquified with a rate of 90 %.NIPU films exhibited tensile strengths of up to 8.5 MPa and showed some food preservation properties.(3)Unsaturated microbial lipids were extracted from the fermentation broth of Rhodotorula viscosus.The NIPU films exhibited a tensile strength of up to 2.57 MPa and good biocompatibility.Overall,the NIPU materials were chemically synthesized by cross-linking cyclic carbonate with amines using biomass-based precursor.The NIPU materials can be extend to various functional applications.