可回收蓖麻油基聚氨酯泡沫的制备与性能研究OA

Castor oil(CO)was used as the raw material to prepare castor oil-based polyphenol(COG)via Friedel-Crafts alkylation.Subsequently,castor oil-based polyurethane foam materials(COGF)were fabricated by reacting COG with CO and polymethylene polyphenylene isocyanate(PM-200).When the addition amounts of COG were 0,20％,40％,60％,80％,and 100％,COF,COGF-1,COGF-2,COGF-3,COGF-4,and COGF-5 were produced respectively.The structure and properties of COGF were characterized by Fourier-transform infrared spectroscopy(FT-IR),thermogravimetry(TG),variable-temperature infrared spectroscopy(VTIR),and other techniques.The results demonstrated the successful synthesis of COG and COGF.With increasing COG loading,the content of rigid cyclic structures in the polyurethane system rose,leading to enhanced mechanical properties of COGF.Compared with COF(without COG addition),the compressive strength of COGF-3 with60％COG added was377.6 kPa,and its specific compressive strength was 2 971 N·m/kg,which were 395％and 389％higher respectively than those of COF without COG added.COGF-3 had the lowest thermal conductivity,with a thermal conductivity coefficient of 0.036 W/(m·K),providing the best thermal insulation performance.The series of COGF materials exhibited good thermal stability,where COGF-5 has a carbon residue rate of 29.2％at 800℃,which was 317％higher than that of COF.VTIR analysis revealed that the decomposition temperature range of the phenol-carbamate linkages in COGF was 80-120℃,which enabled the COGF materials to be reprocessed through dynamic exchange reactions at the elevated temperatures.COGF-5 was pulverized and recovered by hot pressing at 160℃and 20 MPa to obtain castor oil-based polyurethane foam film COGFF-5,exhibiting a tensile strength of 13.4 MPa and a stress relaxation activation energy of 140.67 kJ/mol.Notably,considerable tensile strength was retained even after five cycles of recovery.