Abstract
As chemical recycling of thermosets, the investigation was performed on the novolac epoxy resinification from a thermal decomposition liquid of paper base phenolic resin wastes. The liquid was prepared by treating the wastes at 600°C for 2 hours under nitrogen gas, in which low distillates were removed. The following was the resinification reactions for this liquid, containing phenol, cresol derivatives and methylcarboxylates, as main components. First, the reaction of novolacs : the liquid was reacted with formalin under an acid condition to obtain the novolac product (PFRO). Another novolac (PFR50) was also obtained from the liquid after adding the same quantity of pure phenol. Second, the reaction to opoxies : the novolac epoxy products, EPNO and EPN50, were synthesized from PFRO and PFR50 ubder the condition of excess epichlorohydrin. Their epoxy equivalent values were about 250 and 390g/eq., respectively. The examination was carried out on a few properties of these epoxies cured with triethylenetetramine (TETA), methylnadic anhydride (MNA) and p, p'-diaminodiphenylmethane (DDM). Tgs of EPN50s were about 50°C higher than those of EPNOs each of which was above 100°C with every curing reagent. Flexural strengths and elastic moduli of the cured EPNs with MNA were nearly equal to cured conventional epoxy resins.
