Metal-polymer bond, performance

The exposed regions were etched with concentrated nitric acid. Following a brief water rinse, the tape was removed, the specimen dried and peel measurements performed. After the peel strips were created, the samples were routinely heat treated at 110°C for 16 h to develop the chemical portion of the metal/polymer bond. The specific details of the peel test measurements and set-up have been reported previously . 

A note should be added to a principal difference between methods covered in Sections 4.1 and 4.2, respectively. The methods dealt with in the former section are based on some way of labelling the polymer chain. Thus, all the tags should be present in the isolated polymer and if experiments are performed properly and the data obtained processed accordingly, one should get the correct value C. This may not necessarily be true for methods covered in Section 4.2. The catalyst poison may be consumed not only through the adsorption on the active centers (or through the insertion into the transition metal-carbon bond), but also through an interaction with the species which are not operative in the polymerization by Z—N mechanism. It may lead to an increased value of C. ... 

As a result of the same intra-chain rr-bonding and the relatively strong inter-chain electron transfer interaction, the mechanical properties (Young s modulus and tensile strength) of conjugated polymer are potentially superior to those of saturated polymers. Thus, metallic polymers offer the promise of truly high performance high conductivity plus superior mechanical properties. 

Because of their greater thickness, CAA oxides serve to protect the metal surface from corrosion better than thinner oxides but the important factor for bond durability is the stability of the outer oxide structure when water diffuses to the oxide-polymer interphase. Accordingly, it would be expected that the performance of CAA treated adherends would be similar, although no better, than that of PAA, or BSAA. The wedge test data shown in Fig. 20 and other work [29,77,97,98] support this and demonstrate that when these processes are done correctly the wedge test crack will be forced to propagate entirely within the adhesive. Similar arguments are likely with BSAA adherends, also. 

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