Study on physical properties of poly(methyl methacrylate)/poly(thiophene amide)-silica-titania-grafted multiwalled carbon nanotube-based nanofiber composites

In the present study, poly(thiophene amide) (PTA) was prepared from 1,3-phenylenediamine, 2,4-diaminophenol, and 2,5-thiophenedicarbonyl. Thermally and mechanically stable poly(methyl methacrylate) (PMMA)-based nanocomposites have been produced through the reinforcement of electrospun PTA-silica-titania-grafted multiwalled carbon nanotube (MWCNT-PTA-Si-Ti)-based nanofiber. MWCNT was initially modified to prepare 3-isocyanatopropyltriethoxysilane (ICTOS)-grafted MWCNT via a sol-gel route using 3-isocyanatopropyl-triethoxysilane and titanium(iv) butoxide. The titania-silica network was developed and linked to MWCNT via hydrolysis and condensation. Afterward, the above-prepared ICTOS-grafted MWCNT was electrospun with aramid solution. The electrospun MWCNT-PTA-Si-Ti nanofibers (0.1-1 wt%) were then reinforced in PMMA matrix. Tensile strength and modulus of PMMA/MWCNT-PTA-Si-Ti 0.1 were 42.1 MPa and 8 GPa, which were increased to 44.2 MPa and 15 GPa in PMMA/MWCNT-PTA-Si-Ti 1. Thermal decomposition temperature at 10% weight loss of these PMMA/MWCNT-PTA-Si-Ti 0.1-1 hybrids was in the range of 532-578 degrees C. The glass transition temperature as determined from the maxima of tan data using dynamic mechanical thermal analysis showed an increase with the filler loading and was maximum (313 degrees C) for the composite with 1 wt% MWCNT-PTA-Si-Ti nanofibers.