Application of low molar mass thermotropic liquid crystals as an additive for polymers

Abstract

This research is involved in the applications of low molar mass thermotropic liquid crystals as an additive for several base polymers, including engineering polymers, such as polyamide, polyamide, polyacetal and commodity plastics, such as polyethylene and polypropylene. Melt mixing was the preparation method for blending liquid crystal and base polymers together at 0.1, 0.2 and 0.4 percent by weight of LC. The rheological, thermal and mechanical properties of the blends are investigated in order to compare with the base polymer that absence of liquid crystal. The results show that liquid crystal may improve the processability of the polymer by reducing the melt viscosity of the base polymer while the LCs did not affect the thermal and mechanical properties of the base polymer. So the blends may be applied by using the liquid crystal to increase the capacity of polymer processing process, improve processability of engineering polymer or reduce the energy consumption of polymer processing process. This work also include the preliminary investigation the ternary blend of polymer alloys SAN/PMMA at percent composition of 80/20, 60/40 40/60 and 20/80 weight percent of SAN/PMMA with the ternary component of low molar mass liquid crystal with their binary blend properties. The results of 80/20, 60/40, and 40/60 percent of SAN that represent the partially miscible blend at the studying temperature are as same as the study in the first part that the LC can be reduce the melt viscosity, while not affect the other properties, but at 20/80 percent of SAN, the investigating temperature might be in the phase separation limit which the study temperature might be affected by the two phase blend when added the liquid crystal.