高固含量木材用淀粉胶粘剂的制备及工艺优化研究

he high solid content starch-based wood adhesive was prepared by two seeds process.Firstly,the effect of concentration of hydrochloric acid on viscosity of the high solid content starch-based wood adhesive was studied. Considering the degradation effect on shear strength, choice of hydrochloric acid concentration was 1.0 mol/L.And then two seed polymerization process was applied to further lower the viscosity of the system and improve the adhesive properties. The effect of first/second seed ratio and the second seed adding time on storage stability of the high solid content starch-based wood adhesive were studied. It was shown that,the adhesive showed the lowest viscosity and best storage property when first/second seed ratio and add the second seed after reacting for 2.5h. Finally, the adding amount and manner of APS was optimized: the process of preparation showed to be stable and less reflux on the condition that the adding amount of APS was 1% for starch dry basis, adding 70% of the total at the beginning of the reaction, adding 20% of the total after taking out the second seed and adding the rest after taking in the second seed.The particle size distribution of the high solid content starch-based wood adhesive was analysised on the base of the optimized process which was suggested that starch-based adhesive prepared by two seeds process possesses bimodal particle size distribution. The particles with different sizes can reach the most close packing condition and more emulsifier can be adsorbed on the surface of the small particles to restrain the starch retrogradation which greatly improved the storage property of the high solid content of starch-based wood adhesive.