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

Abstract

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°C. The glass transition temperature as determined from the maxima of tan δ data using dynamic mechanical thermal analysis showed an increase with the filler loading and was maximum (313°C) for the composite with 1 wt% MWCNT-PTA-Si-Ti nanofibers.