Effect of oxalic acid as a pot life extender on viscosity build-up behavior of a telechelic polybutadiene resin
Volume Title: 1
1Chemical Engineering group, Technical Department, Imam Hossein Comprehensive University, Iran
2Chemical Engineering Group, Technical Department, Imam Hossein Comprehensive University
The high-filled composite mixing process is performed in two steps of pre-mixing and curative addition. Hydroxyl-terminated polybutadiene slurry (HTPBS) should have sufficient viscosity at the end of mixing (after curative addition) to allow easy casting at the available time, which called pot life. Long pot-life for the HTPBS is essential for ease of processing and non-defect grain production. There are several ways to extend the pot life of a high-filled composite. Pot life extenders are new materials that are added to the slurry and extend the pot life. One of the recent pot life extenders is oxalic acid, which reduces the curing reaction rate to extend the pot life. In this article, various concentrations of oxalic acid were used at a temperature of 40 0C. The viscosity measurements were performed by a Brookfield rotational viscometer at three different percentages. As the concentration of oxalic acid increases, the rate of increase in viscosity decreases and the pot life increases. The results showed that the addition of %0.05 oxalic acid is the best result that extends pot life from about 240 to 280 mins by playing a probable retarder for curing (polyurethane-network formation) reaction.