变性淀粉接枝丙烯酰胺复配可乳化MDI制备木材胶粘剂

Wood adhesive prepared by compound between modified starch grafted by acrylamide and emulsifiable MDI

以马铃薯氧化淀粉为原料、过硫酸钾(KPS)为引发剂和丙烯酰胺(AM)为接枝单体,制备AM接枝氧化淀粉主剂;然后将主剂与可乳化MDI(二苯基甲烷二异氰酸酯)复配,制备木材淀粉胶粘剂。研究结果表明:制备主剂的最佳工艺条件是m(马铃薯氧化淀粉)∶m(AM)=3.0∶1、反应温度为70℃、反应时间为120 min和引发剂加入时间为40 min;由最佳工艺条件制成的主剂与可乳化MDI复配后,相应木材淀粉胶粘剂的干(湿)态胶接强度明显提高;可乳化MDI掺量可根据胶接强度要求而定,但不宜超过6%(相对于主剂质量而言)。

With potato oxidized starch as raw material,potassium persulfate（KPS） as initiator,andacrylamide（AM）as grafting monomer,the main agent of oxidized starch grafted by AM was prepared. Then,thewood starch adhesive was prepared by compound between main agent and emulsifiable MDI（diphenyl methanediisocyanate）. The research results showed that the optimal process conditions of preparing main agent werepreferred when mass ratio of m（potato oxidized starch）∶m（AM）was 3.0∶1,reaction temperature was 70℃,reaction time was 120 min,and adding time of initiator was 40 min. The dry（wet） bonding strengths ofcorresponding wood starch adhesive were obviously increased when the main agent prepared by optimal processconditions and the emulsifiable MDI were mixed. The emulsifiable MDI content could be determined byrequirement of bonding strength,but should not be more than 6% in main agent mass.