Research Information System
Thesis Type: Postgraduate
Institution Of The Thesis: Gazi Üniversitesi, Fen Bilimleri Enstitüsü, Turkey
Approval Date: 2011
Student: FİGEN ARSLAN
Supervisor: NURSEL DİLSİZ
Abstract:Carbon nanotubes have unique mechanical, electrical, thermal properties and poly(lactic acid) is a biodegradable, biocompatible, compostable polymer. In this study, multiwall carbon nanotube/poly(lactic acid) (MWCNT/PLA) composites were prepared by solvent casting method. MWCNT, MWCNT-COOH, MWCNT-OH and MA-g-MWCNT nanoparticles were used as filler and surface of MWCNT was modified withmaleic anhydride (MA) to get good dispersion in chloroform. The resulting of nanocomposites was characterized by FTIR and ATR spectroscopy, DSC, TGA, DMA, AFM, contact angle measurements and electrical conductivity tests. ATR observations revealed that the maleic anhydride (MA) was covalently attached to the MWCNT (MA-g-MWCNT). 3D (3 dimension) images which were gotten from AFM analysis indicated the best nanoparticle-matrix attractive in the MA-g-MWCNT/PLA film. So, it can be said that wettability by PLA matrix of functionalized MWCNT nanoparticles with maleic anhydride is very good. DMA analysis indicated the most efficient bonding was seen in MA-g-MWCNT/PLA nanocomposite with 3 wt% MA-g-MWCNT content due to the shift to high temperature of tan δ value. As well, thermal degradation of results demonstrated enhancement properties of PLA where initial decomposition temperature increased from 328,91 oC to 347 oC with the addition 0,5 wt% MA-gvii MWCNT. It was seen, from DSC analysis the glass transition temperature (Tg) of MWCNT-OH/PLA nanocomposite increased from 85,78 to 87,74 and these values were higher than neat PLA. At the same time, contact angle measurements revealed that the MWCNT-OH/PLA films were strongly hydrophilic from the others due to icluding OH groups. On the other hand, the surface resistance of composite film decreased from 2,56x109 Ω to 2,42x103 Ω (by 106 order) for the 3 wt% MWCNT-COOH/PLA. Notably, improvements of different properties were achieved in nanocomposite fims when changing CNT surface modifying.