Relative importance of thermal cracking and reforming during binder removal from ceramic/polymer composites

The authors investigate the influence of furnace atmosphere and temperature on the degradation mechanism of the binder and the size and type of degradation products formed during binder removal. Such information will provide a guide for the development of an improved ceramics fabrication process. Thermogravimetric analysis-mass spectrometry (TGA-MS) techniques were used to investigate removal of organic binder material from a ceramic/polymer composite by thermochemical means. These studies indicate that the type of degradation mechanism employed strongly influences (i) the rate at which the organic components are fragmented, (ii) the size distribution of fragments, and (iii) the fraction of fragments that recombine to form higher molecular weight (and possibly crosslinked) moieties subsequently difficult to degrade except at higher temperatures. The degradation mechanism may thus dictate process economics, the magnitude of sample-damaging stresses generated during binder removal, and subsequent densification behavior. The TGA/MS technique is thus a powerful quantitative tool for the understanding and development of advanced materials fabrication processes.