Abstract
SynopsisCarbon-neutral materials, which do not affect the density of CO2 in the atmosphere even if they burn, have attracted much attention from the viewpoint of environmental friendliness. In this study, waste medium for cultivation of plant (natural lignocellulose) was decomposed stepwise and converted into the useful materials for epoxy/hardener system which were not derived from petroleum. In the first decomposition, the natural lignocellulose was treated with high-pressure hot water.The epoxy resin containing the hydrothermally treated lignocellulose (HLC) fillers had the higher fracture toughness than that of the base epoxy resin (without fillers). Therefore, the HLC works an organic filler. In the next decomposition, the HLC was treated with acidic H2O/C2H5OH solution under high temperature and pressure. The prepared acidolysis lignin(ALG), which had lower molecular weight than that of the HLC, was utilized as a hardener for epoxy resin. Moreover, the epoxidized ALG (ep-ALG) was prepared by epoxidation of the phenolic group of the ALG. The measurements of cross-link density and glass transition temperature of the epoxy/hardedner/ep-ALG system demonstrated that the ep-ALG with high cross-link activity improved heat-resistance of conventional epoxy/hardener system.
