WATER ABSORPTION AND THERMAL PROPERTIES OF PMMA REINFORCED BY NATURAL FIBERS FOR DENTURE APPLICATIONS

The water absorption and thermal conductivity of denture base materials are important properties due to effect on dimensional stability and sensory of food during mastication. This paper discusses the effect of two natural fibers (siwak and bamboo) which used as reinforcement for properties (water absorption and thermal conductivity) of PMMA. The two kinds of fibers used in three different lengths (2, 6 and 12mm) and three concentrations (3, 6 and 9 wt. %). The results showed that the percent water absorption, thermal conductivity and thermal diffusivity increased with increase fiber length and weight fraction. The highest values of water absorption for bamboo specimens and siwak specimens (6.21 % and 7.21 % respectively) at (9wt.%) and (12mm) fiber length. The maximum values of thermal conductivity and thermal diffusivity for bamboo specimens (0.2216 W/m0K and 0.1628 mm2/sec), while for siwak specimens (0.2408 W/m0K and0.1747mm2/sec), respectively at optimum condition of (9wt. %) and (12mm) fiber length.