Abstract:
In order to investigate the influence of moisture resistance agents chlorinated paraffin and glycerol on the moisture resistance, microstructure and chemical structure of wheat straw/vegetable protein adhesive composites, composites added with two moisture resistance agents were prepared by hot pressing molding method. The mechanical properties, water and moisture absorption rate variation of wheat straw/vegetable protein adhesive composites were measured respectively, and the functional group variations were analyzed by FTIR. The wettability was analyzed by testing contact angles, and the bending cross-section microstructure of the composites was observed by the stereo microscope.The results show that the maximum bending strength and bending elastic modulus of wheat straw/vegetable protein adhesive composites adding chlorinated paraffin increase by 67% and 129% respectively compared with those of wheat straw/vegetable protein adhesive composites without additive. The maximum impact strength of wheat straw/vegetable protein adhesive composites adding glycerol increases by 44% compared with that of wheat straw/vegetable protein adhesive composites without additive. The 2 h thickness swelling rate of water absorption of the wheat straw/vegetable protein adhesive composites adding chlorinated paraffin and glycerol are generally smaller than that of composites without additive. With the moisture absorption time increasing, the moisture absorption rate of three composites increases, and the smallest rate of balanced moisture absorption of wheat straw/vegetable protein adhesive composites adding chlorinated paraffin is 4.3%. The bending cross-section microstructure of wheat straw/vegetable protein adhesive composites adding chlorinated paraffin is better than that of other composites, the inner surface is integrated tightly and the surface of the fiber is less exposed and the moisture resistance is the best.