Effect of graphite and MAX on some properties of N-vinyl carbazole and benzyl methacrylate copolymer

In this thesis, P(NVC-co-BZMA) copolymer was synthesized by using free radical polymerization method with N-vinyl carbazole (NVC) and benzyl methacrylate (BZMA) monomers. The polymerization process was carried out at 70 oC in 1,4-dioxane solvent and Azobisisobutyronitrile (AIBN) was used as initiator. Structural analysis of the obtained copolymers was performed by FT-IR, 1H-NMR and surface morphology was examined by SEM images. The composition of the copolymer was calculated from the 1H-NMR spectrum. It was determined that 53% NVC and 47% BZMA units were present in the copolymer. The copolymer was named as P(NVC0.53-co-BZMA). The glass transition temperature (Tg) was determined by DSC. Composites of the copolymer with graphite (GR) and MAX phase (Ti3AlC2) were prepared in four different ratios. FT-IR spectra and SEM images of the composites were also analyzed. Glass transition temperatures were determined by DSC and it was observed that Tg values increased with the doping of the copolymer. The thermal stability of the copolymer and composites were investigated using TGA thermograms. The thermal degradation kinetics of P(NVC0.53-co-BZMA) copolymer and 80%P(NVC0.53-co-BZMA)-10%GR-10%MAX composite were investigated and the average activation energies were determined using (Flynn-Wall-Ozawa) FWO and (Kissinger-Akahira-Sunose) KAS methods. The average activation energies of P(NVC0.53-co-BZMA) copolymer were found to be 178.3 and 176.6 kj/mol according to FWO and KAS methods, respectively. The average activation energies of 80%P(NVC0.53-co-BZMA)-10%GR-10%MAX composite were calculated as 158.2 and 155.5 kj/mol according to FWO and KAS methods, respectively. The dielectric properties of both copolymer and composites were investigated. At 1 kHz, the dielectric constant of the copolymer was found to be 2.22 while that of the 10%GR doped composite was 12.31. The composites made with 10%GR and 10%GR-10%MAX doping of the copolymer were found to be semiconductors.