Analysis of Polymeric Materials:

The thermogravimetric analysis has extremely versatile application within polymer analysis, the acquired information through TGA is confined to the detection of modify in mass of the sample as its temperature or time duration alters. The method is used to study the decomposition, oxidation reactions and also a few physical processes like as vaporization, desorption and sublimation. The major conclusion drawn through TGA is: thermal stability, compositional analysis, and life time assessment and degradation kinetics. The TG curve provides information about the decomposition of several polymers that might be used for identification purposes and also assessment of thermal stability. The primary route through which a polymer degrades could be categorized according to following mechanism:

1.         Main chain scission

2.         Side chain scission

3.         Elimination

4.         depolymerisation

5.         cyclization

6.         Cross-linking

Out of the above steps only 1-4 lead to change in mass and can be detected in TGA. Figure is displaying thermogravimetric analysis of Poly Methyl Methacrylate (PMMA), Polyvinyl Chloride (PVC), High Density Polyethylene (HDPE), Polytetrafluoroethylen (PTFE) and Polystyrene (PS). The polymer begin degradation at the extrapolated onset of the lowest temperature mass loss or quote the temperature at that 5 percent mass loss has taken place. The PVC starts degradation at lower temperature ~ 150 °C and takes place in two steps although NYLON -6, LDPE and PTFE begins degrading at higher temperatures 400 °C, 450 °C and 550 °C correspondingly and in single steps. Qualitatively, the higher the decomposition temperature, the more positive is the ? G value at room temperature and the greater the stability. This could predict the associative stability of the polymers.

The thermogram display in Figure provides information about the associative composition of constituents in analyzed poly (ethylene-co-vinyl acetate) copolymers. A vinyl acetate component displays features mass-loss associated along with elimination of acetic acid before the main chain degradation occurs. In that case TG could be used as quantitative means of estimating copolymer composition.