Investigation of thermal degradation of some adhesives used in the automobile industry by thermal analysis/mass spectrometry and GC-MS

Abstract

In order to make a direct evaluation of adhesives used in bond welding in the automobile industry we used the so-called “black box” approach. In this case we only know the trade name of the adhesive but not any 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 spectrometry. Modelling the real situation in bond welding, we made pyrolysis experiments in the German VCI-oven in air. The volatile and semivolatile 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 theory, the results (output) were referred to adhesive type used (input). This approach is not restricted to investigating adhesives, but can be applied to all cases where high temperature must be used in the presence of organic materials. The adhesive types investigated were three epoxy resins, one component polyurethane and one butyl-chaoutchouc.