Dielectric, thermal and mechanical properties of sawdust reinforced epoxy composites post-cured in microwaves

摘要

[Abstract]: To process composites, post-curing with heat is often required in order to achieve the desired heat distortion temperature (HDT). Post-curing the composites with conventional oven would often take 6 or 8 hours. However, if the composites are post-cured in a microwave oven, it only requires a few minutes. Hence, the aim of the project is to investigate the suitability of microwave for material processing. Epoxies are polyethers and they are widely used to produce coatings, structural adhesives because they have excellent adhesion and low cure shrinkage. Epoxies are also good dielectric and have been used to manufacture printed circuit boards (PCB).ududThe main objectives of this project are:udud• To produce specimens with different percentage by weight of sawdust.ud• To measure the loss tangent and dielectric constant of the specimens.ud• To measure the tensile strength of the specimens.ud• To measure the glass transition temperature of the specimensud• To consider both of the material costs and the test results to recommend the best specimens for different industrial applications.ududThis report has found that the sawdust reinforced epoxy resins have higher Young’s modulus, higher dielectric constant but lower tensile strength and yield strength. The loss tangents of the sawdust reinforced epoxy resins were slightly higher than the loss tangents of pour epoxy resins. Hence, the sawdust reinforced epoxy resin is slightly more efficient to be post-cured in microwave than pure epoxy resin. This report has also found that oven cured epoxy resins have the lowest dielectric constant, the lowest loss tangent, and the highest glass transition temperature. Hence, oven cured epoxy resin is the best candidate for making PCBs.