Heat Capacity Study of Electrospun Poly(trimethylene terephthalate) Composite NanofibersContaining Carbon Nanotubes

摘要

Nanofibrous composite mats were prepared by electrospinning of poly(trimethyleneterephthalate), PTT, with multiwalled carbon nanotubes (PTT/MWCNT). Trifluoroacetic acid(TFA) and methylene chloride (MC) with volume ratio of 50/50 is a good solvent for PTT and wasused as the electrospining solution. Scanning electron microscopy was used to investigate themorphology of electrospun (ES) nanofibers with 0 and 1.0wt% of MWCNTs. Thermal propertieswere investigated using heat capacity measurements under temperature modulated differentialscanning calorimetry (DSC) using the three-runs method for baseline correction, heat flow amplitudecalibration, and sample heat capacity determination. A model comprising three phases, a mobileamorphous fraction (MAF), rigid amorphous fraction (RAF), and a crystalline fraction (C), isappropriate for ES PTT/MWCNT mats. The phase fractions, Wi (for I = RAF, MAF or C) weredetermined by DSC. Crystallinity decreases very slightly with the amount of MWCNT loading.At the same time, a large increase in RAF was observed: WRAF of PTT fiber with 1% MWCNT isalmost twice that of homopolymer PTT fiber. The addition of MWCNTs enhanced the PTT chainalignment and increased RAF as a result.