聚乙烯醇缩丁烯醛胶粘剂的改性研究

Study on modification of adhesives based on poly(vinyl butenal)

以聚乙烯醇(PVA)和丁烯醛为主要原料、盐酸(HCl)为催化剂和乙醛为改性剂,制备聚乙烯醇缩混合醛胶粘剂。采用单因素试验法探讨了各因素对胶粘剂的黏度、粘接强度和耐水性等影响。结果表明:当反应温度为(90±2)℃、反应时间为4 h、8%PVA溶液为200 mL、HCl为1 mL、丁烯醛为1.0～1.5 mL和乙醛为4 mL时,缩醛化产物的黏度适中、粘接强度相对最大(4.5 MPa)且耐水性相对较好;在其他条件保持不变的前提下,通过改变丁烯醛用量,可以进一步调节体系的最终黏度,使之满足木材用胶粘剂的使用要求。

With polyvinyl alcohol（PVA） and butenal as the main raw materials,HCl as catalyst and aldehyde as modifier,the poly（vinyl mixing acetal） adhesive was prepared.The influences of various factors on viscosity,bonding strength and water resistance of the adhesive were discussed by single factor experiment.The results showed that the acetal product had appropriate viscosity,relative maximum bonding strength（4.5 MPa） and relative better water resistance when the reaction temperature and time were（90 ± 2） ℃ and 4 h respectively,8% PVA solution and HCl were 200 mL and 1 mL respectively,butenal and aldehyde were 1.0-1.5 mL and 4 mL respectively.The final system viscosity,which was adjusted by changing butenal contents,could meet the application requirement of adhesive for wood when other conditions were unchanged.