Fluoroelastomer Specialists
The four main techniques used were Differential Scanning Calorimetry (DSC), Thermal Gravimetric Analysis (TGA), Thermomechanical analysis (TMA) and Dynamic mechanical analysis (DMA), either alone or in conjunction.
Measuring Glass Transition of Elastomers with ADSC Measurements
Section two details the DSC characterization of a common thermoplastic polymer, polyethylene terephthalate (PET), which is commonly used for food and drink applications. Measurements carried out using DSC include glass transition, cold crystallization, recrystallization, melting point, thermal history, oxidation induction time, oxidative stability and decomposition.
All of these parameters are discussed and the pitfalls pointed out in the context of thermoplastic polymers. In addition new DSC techniques were used including TOPEM, a new temperature modulated DSC technique, introduced by Mettler-Toledo where stochastic temperature pulse modulations are superimposed on the underlying rate of a conventional DSC scan. This means it is possible to distinguish frequency-dependent phenomena from frequency-independent phenomena and this has application to both glass transition and crystallisation.
In section three the subject of thermoplastic polymers is continued with TGA, TMA and DMA techniques used to examine effects such as decomposition, expansion, cold crystallization, glass transition, melting, relaxation and recrystallization in PET. TGA, TMA and DMA all yield valuable complementary information to DSC measurements. TMA was elaborated on in connection with dilatometry (measurement of shrinkage) and penetration measurements. A comparison of all four techniques used in these two sections showed a good agreement of results as often a particular effect can be measured by different thermal analysis techniques. These two sections also gave good analytical methodology where polymers are first investigated by TGA, then by DSC and TMA, and finally by DMA to obtain a comprehensive physical and mechanical profile.
The thermosetting polymer KU600, an epoxy resin derivative used as a coating material for electrical and electronic components, was analysed by DSC, TGA, TMA and DMA in sections four and five. The experiments here demonstrated how a combination of thermal methods can be used to determine the activation energy/kinetics of heat promoted changes in the polymer during curing as well as specific heat capacity (Cp) and Young’s Modulus. Both of these measurements bear upon the overall stability of the material when it is used in electrical applications. These sections also examined adjunctive methods, such as:
Read more: Thermal Analysis of Polymers: Application Booklet
