| Influence of alkaline strength on the bonding strength of soybean protein adhesive was studied. With self made soybean protein adhesive as raw material, soybean protein adhesives with different pH were prepared by sodium hydroxide titration, and the bonding strength was determined. The infrared spectrum and DSC test were carried out. The results showed that with alkaline enhancement, the bonding strength of soybean protein adhesive decreased firstly, then increased and then decreased, and reached peak at pH 11. The trends of wet bonding strength and dry bonding strength were consistent. The absorption peak position of the infrared spectrum didnt change, but the absorption intensity changed, resulting in a change in the bonding strength.The glass transition temperature of soybean protein adhesive decreased first and then increased with the increase of pH. The glass transition temperature reached a minimum of 76.55?℃at pH 10, and a maximum of 84.74?℃ at pH 12. |
