Abstract:
This study investigated the reinforcement of epoxy resin with chicken egg shell powder. The egg shells in the study were the waste of chicken eggs used in making Thai dessert, in which eggs are an important ingredient for creating a unique flavor. It has been proven that over 97% of an egg shell is composed of calcium carbonate and 3% of other organic substances. Plastic industries have been using calcium carbonate as fillers to reduce the usage of plastic, improve the surface quality and control the shrinkage of plastic products.
This research studied the mixing ratios of egg shell powder in epoxy resin, effects of the powder sizes and the coupling agents in the forming process of composite materials derived from egg shell powder reinforced in epoxy resin. The first step studied the removal of the egg membrane. It was found that a sodium hydroxide solution could remove the membrane thoroughly. After that, the egg shells were ground and sieved to the sizes of 75, 100, 200 and 325 mesh. Then, composites were formed by mixing egg shell powder with epoxy resin in the ratios of 15, 35 and 50% w/w respectively. Mechanical tests were conducted on the composites to evaluate their properties. The final step investigated the improvement of the composites mechanical properties by using coupling agents.
The results showed that the best mechanical properties were achieved when the composite consisted of 200 mesh egg shell powder at the mixing ratio of 15 % w/w. Meanwhile, among the silane coupling agents, KH560 could improve the mechanical properties significantly, which was confirmed by the results of the mechanical testing and morphology of the composite materials. In additional, the results of this study were analyzed, using the factorial variance analysis technique. It was concluded that the sizes and mixing ratios of egg shell powder affected the mechanical properties at 95% confidence intervals.