INVESTIGATION OF THERMAL-DEGRADATION OF SOME ADHESIVES USED IN THE AUTOMOBILE-INDUSTRY BY THERMAL-ANALYSIS MASS-SPECTROMETRY AND GC-MS

In order to make a direct evaluation of adhesives used in bond welding in the automobile industry we used the so-called ''black box'' approa ch. In this case we only know the trade name of the adhesive but not a ny further information about the raw materials. To obtain information from the thermal behavior of adhesives, we conducted thermoanalytical experiments in an inert atmosphere and coupled thermal analysis/mass s pectrometry. Modelling the real situation in bond welding, we made pyr olysis experiments in the German VCI-oven in air. The volatile and sem ivolatile products of pyrolysis were collected on XAD-resins and after elution, qualitative and quantitative determinations were carried out by gas chromatography/mass spectrometry. According to black box theor y, the results (output) were referred to adhesive type used (input). T his approach is not restricted to investigating adhesives, but can be applied to all cases where high temperature must be used in the presen ce of organic materials. The adhesive types investigated were three ep oxy resins, one component polyurethane and one butyl-chaoutchouc.