Abstract: Polyurethane resin was synthesized by benzy lated wood solution using mixture of dibasic esters(DBE) and n-butylacetate as solvents with the adduct of toluene diisocyanate(TDI) and trihydroxyme thylpropane, and then the resin was treated by different heating methods. FT-IR, DSC, DTA and TG are used to characterize the resin. All results showed that heat treamtent method plays an important role on microsphase separation and therm al property of theresin. The degrees of microphase separation under different heat treatment methods are in the sequence of: norm al temperature so lidifying(S) > annealing (A) > quenching (Q). The initial decomposing temperatures during hard-stage are in the sequence of S> A > Q, while the initial decomposing temperatures during soft-stage are in the sequence of:S< A < Q.

Key words: polyurethane, microsphase separation, benzylated wood