Preparation And Properties Of Thermal Conductive Phthalonitrile-terminated Poly (Arylene Ether Nitriles) Composites

The cross-linkable poly(arylene ether nitriles) terminated with phthalonitrile(PEN-t-ph) possesses outstanding chemical properties, good thermal stability as well as high mechanical strength. The thesis dealt with the methods and processes of preparation of high thermal conductive PEN-t-ph polymer composites. To improve the interfacial compatibility between polymer matrix and inorganic filler, the filler were surface modified previously. And modified alumina(Al2O3), colloidal graphite(CG), and multi-walled carbon nanotube(MWCNT) were synthesized as a conducting additive to improve thermal conductivity properties of PEN-t-ph polymer, respectively. Scanning electron microscopy(SEM), thermogravimetric analysis(TGA), fourier transform infrared(FTIR), UV-vis spectroscopy, and X-ray diffraction(XRD) were employed to investigate the morphologies and structures of the modified filler. Furthermore, the structures, fracture morphologies, thermal, mechanical and thermal conductivity properties of the PEN-t-ph composites were investigated.It was found that polymer-based composites filled with Al2O3 could improve the thermal conductivity of polymer. For the incorporation of hybrid micro and nano Al2O3, the thermal conductivity of the composite came up to increase rapidly than single filling. As expected, the remarkable enhancement in thermal conductivity of the composites was achieved with the addition of CG. The thermal conductivityof sample with 16 wt% CG-CuPc reached the maximum value(0.597 W/(mK)). As the MWCNT was introduced to the polymer, the results showed that with the increase of the content of MWCNT, the thermal conductivity of MWCNT/PEN-t-ph composites improved slowly. When the content reached certain critical value, the thermal conductivity increased rapidly. The thermal conductivity of the composites reached the maximum(0.881 W/mK), with a 270% increase compared to the pure polymer. The tensile strength increased with the increase of the content of filler, and then tended to decrease gradually as the content exceeded the critical value. The TGA curves indicated that all sample showed excellent thermal stabilities with initial degradation temperature(Tid) above 490 oC. DSC curves revealed that the glass transition temperature(Tg) of all samples were up to 170 oC.