Contribution of Chemical Interactions Between Different Types of Functional Groups and Metal Atoms to the Adhesion of Metal-Polymer Composites

摘要

Pulsed plasma polymerised allyl alcohol, allylamine and acrylic acid were used as adhesion-promoting layers in aluminium-PP composites. To vary the density of functional groups a chemical copolymerisation with ethylene or butadiene was plasma-chemically initiated. In general, the measured peel strength of aluminium deposits increase linearly with the concen-tration of functional groups. Near the maximum concentration of OH (～27 OH per 100 C at-oms) or COOH (～10 COOH per 100 C atoms) a constant peel strength was measured. For OH group carrying interlayers the peel strength decreases dramatically for the pure allyl alcohol layer caused by its poor cohesive strength. The succession of the adhesion-promoting effect was derived from the slope of the linear increase of the peel strength vs. concentration of functional groups: CH_2 - CH_2 < NH_2 < < OH < COOH. The mode of failure was inspected by XPS. The influence of functional groups bonded by a well-defined spacer to the surface on the peel strength between polymer and metal coating was tested.