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This article is based on soy protein isolate (SPI) as a raw material , chemical modification in order to improve its adhesive properties of SPI ; using a phosphorylating agent , sodium tripolyphosphate ( STP ) , the acetylating agent acetic anhydride , succinic acylating reagent succinic anhydride and urea modified and degeneration of an organic solvent SPI, modifications and after denaturation of SPI as adhesiveness and water resistance of the wood adhesive of the two methods composite modified the SPI their viscosity , adhesive strength and water resistance ; SPI as raw material, 7S and 11S globulin extraction as well as adhesive properties , mechanism of SPI from the adhesive characteristics was discussed . Experimental results show that phosphorylation, acetylation, the succinylated and urea-denatured SPI adhesive strength can be improved , but not acetylation and succinic acylating on the SPI water , the succinic acylating even reduce the water resistance , wherein the effect of phosphorylation of the method is preferably when added in an amount of 8% of the STP , the SPI adhesive strength and water resistance have reached the maximum value. The circular dichroism spectra show that the content increased after phosphorylation SPI secondary structure , random coil , the secondary structure becomes more disordered , STP amount of 8 % , a content of 35.3% the SPI random curling , the unmodified SPI random coil content of 28.6% . The urea-denatured , and phosphoric acid , urea and pH denatured two methods composite modified SPI, compared with single chemical modification method , the urea concentration for 3mol / L , and pH for 10 hours , the resulting adhesive strength , water resistance is also very well. Extracted from the SPI the 11S globulin adhesive strength and water resistance than the 7S globulin and SPI , SPI , the largest contribution to the adhesive characteristics 11S globulin . 7S and 11S globulin using various concentrations of urea denaturation, 1mol / L urea denaturing effect to improve the adhesive properties of the best . DSC analysis of the data showed that the greater the concentration of urea , 7S and 11S denaturation temperature and enthalpy lower urea concentration of 5mol / L , 7S and 11S globulin enthalpy value is 0. Finally , the use of urea-denatured and phosphorylation -modified the two methods composites modified 11S globulin , found from the experimental results of these two methods is not possible to improve composite a 11S globulin adhesive characteristics .
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