( 中南大学 材料科学与工程学院, 长沙 410083)
摘 要: 研究了在砂纸打磨、 硅烷偶联剂处理铝板表面两种条件下,马来酸酐接枝聚丙烯(MPP)含量对铝薄板/聚丙烯界面粘接剪切强度的影响。 聚丙烯中不含MPP时, 粘接剪切强度分别为3.44和4.57 MPa;添加MPP后, MPP的酸酐基团及其水解形成的羧基与铝板表面羟基、 Al3+发生界面化学反应, 粘接强度得以大幅提高。 MPP含量为20%时, 粘接强度分别达到最大值10.30和10.64 MPa。 MPP含量继续增大时, 在铝板表面形成较低分子量MPP的聚集区, 且该区与MPP贫乏区之间的分子链缠结作用弱, 导致铝板/聚丙烯的界面粘接强度随MPP含量增加而下降。
关键字: 铝薄板; 聚丙烯; 马来酸酐接枝聚丙烯; 界面; 粘接强度
shear strength of adhesion bonded aluminum sheet/polypropylene/aluminum sheet
( School of Materials Science and Engineering,
Central South University, Changsha 410083, China)
Abstract: The effect of amount of maleic anhydride grafted polypropylene(MPP) in copolymer of polypropylene(PP) and MPP on shear strength of adhesion bonded aluminum sheet/polypropylene/aluminum sheet was investigated under surface pretreatments of Al sheet by sand grinding, γ-aminopropyltriethoxy silane solution after sand grinding respectively. For pure PP, the adhesion strength is between 3.44-4.57 MPa. It shows obvious promotion of the adhesion strength with 5%-30% amount of MPP in the copolymer due to the interface interaction between —OH,Al3+ at surface of the Al sheet and —COOH, carboxyl groups on MPP. The maximum values of the adhesion strength, 10.3 MPa and 10.64 MPa for the two surface treatments respectively, are obtained with 20% MPP. With increase of MPP content, the adhesion strength decreases due to the formation of a weak layer of higher content of MPP with low molecules, and low connectivity strength between the layer of higher content of MPP and the layer of high content of PP.
Key words: aluminum sheet; polypropylene; maleic anhydride grafted polypropylene; interface; adhesion strength