چكيده لاتين :
Recently, it has been shown that the addition of a small quantity of nanoclay can greatly enhance the efficiency of low profile additives (LPAs) on volume shrinkage
control of low profiled unsaturated polyester (UP)/styrene/LPA systems. In this study, however it was found that the organically-modified nanoclay (Cloisite 15A) can also affect the volume shrinkage control of non-low profiled UP/styrene systems. The effect of nanoclay on volume shrinkage of UP resin was investigated by an inhouse
constructed shrinkage measurement apparatus. Experimental results revealed that the nanoclay somewhat decreases the volume change of UP/styrene system. The polymerization kinetics of the nanoclay filled UP systems was studied in a quasi-adiabatic reactor. The quasi-adiabatic exothermic measurements showed that, at higher nanoclay content, the reaction rate increased and the induction time decreased. The reduced viscosity measured by a rheometric dynamic analyzer. The gel time calculated by both quasi-adiabatic reactor and rheometric dynamic analyzer data. Results have showed thataddingnanoclayintothe UP/styrenemixturemakestheonsetofthe viscosityrise happen much earlier which leads to a higher reaction rate, faster viscosity rise, and earlier gelation. It is clearly observed that measuring the gel time at different level of Cloisite 15A is similar to using rheometry and exothermic experiments.