Akademik Veri Yönetim Sistemi
JOURNAL OF POLYMER ENGINEERING, cilt.34, sa.9, ss.793-802, 2014 (SCI-Expanded)
Novel high thermally stable polyimide-chrysotile (PI-Chr) composites were synthesized. Firstly, Chrysotile (Chr) was modified with 3-aminopropyltriethoxysilane (APS). Poly(amic acid) solution was synthesized from pyromellitic dianhydride (PMDA) and 4,4'-diaminodiphenyl ether. Then, PI-Chr composites were prepared from poly(amic acid) solution and different ratios of modified Chr. Prepared PI-Chr composites were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray spectroscopy and thermal analysis techniques. Thermal analysis results showed that the PI-Chr composites have higher decomposition temperatures in comparison with the pure PIs. A 10% weight loss belonging to PI-Chr composites was observed between 489 degrees C and 536 degrees C in air atmosphere, but this value was 468 degrees C in air for pure PIs. The glass transition temperatures (T(g)s) of the PI-Chr composites were 373 degrees C-38 degrees C, depending upon the amount of the Chr. PI-Chr composites exhibited improved thermal stability. The activation energies (E(a)s) of the thermal degradation reaction were calculated using the Kissinger method for pure PI and composites. The E(a)s of the PI-Chr composites were found to be 77 and similar to 117 kJ/mol. The fire retardant properties of Chr in the PI matrix were also tested by the total heat release test. The introduction of Chr in the composites leads to a slight increase in fire retardant properties thermal stability.