Thermosetting starch adhesive for wood-based panel and preparation method therefor

A preparation method for a thermosetting starch adhesive wherein thermosetting starch adhesive for a wood-based panel comprises, in parts by mass, 100 parts of starch, 300-500 parts of water, 6-18 parts of concentrated hydrochloric acid, 10-20 parts of sodium hydroxide, 1-2 parts of an initiator, 60-80 parts of a grafting monomer, 2-9 parts of a crosslinking monomer, 1-3 parts of an emulsifier, 0-10 parts of a diluent, 10-25 parts of an antifoaming agent, and 0.01-0.04 part of a polymerization inhibitor;

• and wherein the preparation method comprises:
• preparing a seed emulsion by stirring a part of the grafting monomer, the emulsifier, and the initiator well to be used as the seed emulsion;
• performing acid hydrolysis of a starch emulsion made of the starch as a main raw material, adjusting pH of the starch emulsion to pH 4-5, and then adding the seed emulsion to the starch emulsion to form a reaction mixture for starting a grafting reaction;
• adding a first portion of the remaining initiator and gradually adding dropwise the remaining grafting monomer to the reaction mixture, incubating the reaction mixture for 3-5 hours, and adding a second portion of the remaining initiator and the cross-linking monomer by a semi-continuous method to react for 2-6 hours;
• heating the reaction mixture, and incubating for 0.5-1 hour;
• next, removing the residual monomer;
• and finally, cooling down the reaction mixture, adding the polymerization inhibitor and urea, and discharging the resulting mixture after mixing well, thereby obtaining the thermosetting starch adhesive.