| Summary: | 碩士 === 朝陽科技大學 === 應用化學系碩士班 === 98 === In this study, polyamic acid prepolymer is prepared through three monomers: 4,4′-Oxydianiline (ODA), 3,3''-Dihydroxybenzidine (HAB) and Pyromellitic dianhydride (PMDA). Then the coupling agent (3-Isocyanatopropyl triethoxysilane IPS) was added and the hydroxy group on the HAB will further react with the IPS. Subsequently, the high thermal conductive inorganic matters: multi-walled carbon nanotube (CNTs) and boron Nitride (BN) were added into the polymer matrix, and the thermal imidization was then proceeded by dehydration via heating process. The morphology, mechanical, thermal and electrical properties of these composites were investigated.
By the scanning electron microscopy (SEM), surface morphology of composite materials showed that good compatibility between PI and inorganic filler was found. Thermal gravimetric analysis (TGA) showed that thermal properties of polymer materials have been enhanced with the addition of CNTs and BN. Dynamic Mechanical Analyzer (DMA) showed that the increments of the storage modulus (E'') and loss modulus (E") for PII series loading with 40wt% of CNTs and BN, are 85.9% and 144.20%, respectively. Moreover, tensile strength and elongation at break are decreased with the increasing content of fillers. Further, the decreased dielectric constant and increased surface resistance were found with the increasing content of BN. The thermal conductivity of Polyimide was increased from 0.3657 W/mK to 0.8194 W/mK as adding of 40wt% of CNTs and BN. This indicates that the conductive paths and networks were formed, and can help the heat dissipation of composite materials.
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