Rheological Comparison of Silicone Rubber Crosslinking with Platinum Catalysts and Triethylamine, Methanol & Ethanolamine Solvents

Abstract

The control of silicone rubber’s viscoelastic properties such as loss factor, storage and loss moduli at crosslinking stage is crucial in their malleability. Hence, the objective in this study is to investigate the rheological behaviour of silicone rubber cured under different formulation using platinum catalysts and triethylamine, methanol & ethanolamine solvents. Measurements were conducted for the silicone rubber to cross-linker ratios of 2.5:7.5, 5:5, 7.5:2.5 and 10:1 at different temperatures, as well as for the silicone rubber with triethylamine, methanol and ethanolamine at different angular frequencies. The crossover of storage and modulus curve which signifies a gel point was not observed at higher ratios of platinum used across the temperature range of 25 – 100°C. However, the crossover was observed at 89 and 95°C with the formulation ratios of 10:1 and 7.5:2.5, respectively. On the other hand, the crossover point was observed for silicone rubber at 100 s-1 for triethylamine, 3 s-1 and 100 s-1 for methanol, and 70 s-1 alongside 290 s-1 for ethanolamine. The presence of gel point indicates that crosslinking of silicone rubber and this study proves the possibility of controlling the crosslinking behaviour..