Modularising thermogravimetric analysis (TGA) and its applications to a wet process masterbatch plant
2013
Sum, N. C.
Thermogravimetric analysis (TGA) is indispensable in analysing the composition of rubber compounds. In the TGA test, a rubber compound is fractionated into four fractions comprising liquid or low melting point solid, polymers, carbon black and mineral fillers. Small sample weight can result in large errors for rubber compounds that are not fully dispersed. Test equipment is expensive and therefore it is not a suitable choice for large numbers of production samples. Density measurement of rubber compound is a viable alternative for a quick test. Both these tests were initially applied to a production line of wet process masterbatch plant and shortcomings of these two methods were enumerated. An alternative testing scheme involving thermogravimetric and solvent extraction has been devised and tested successfully. Samples of the same compound with different weights were tested via Soxhlet solvent extraction, nitrogen pyrolysis and oxygen pyrolysis. The results were combined mathematically and basic equations were derived. Test variability was low and comparable to conventional TGA using microbalance. Results were correlated with elatest density measurements, although the 1:1 unity line correlation was not possible. Assumptions were made on the full incorporation of low melting point solids, as well as densities of various components and these could explain the discrepancies observed. Modularisation of TGA test allows for improvements in the component test method. A large number of tests were carried out in a continuous production line turning out carbon black masterbatches.
显示更多 [+] 显示较少 [-]