Poly(trimethylene terephthalate) nanocomposite fibers comprising different organoclays: Thermomechanical properties and morphology

Abstract

Poly(trimethylene terephthalate) (PTT) nanocomposites were synthesized by in situ polymerization at high temperature with two thermally stable organoclays: 1,2-dimethylhexadecylimidazolium-montmorillonite (IMD-MMT) and dodecyltriphenyl phosphonium-MMT (C12PPh-MMT). PTT hybrid fibers with various organoclay contents were melt-spun at various draw ratios (DRs) to produce monofilaments. The thermomechanical properties and morphologies of the PTT hybrid fibers were characterized using differential scanning calorimetry, thermogravimetric analysis, wide-angle X-ray diffraction, electron microscopy, and mechanical tensile properties analysis. The nanostructure of the hybrid fibers was observed by both scanning and transmission electron microscopy, which showed that the clay layers were well dispersed into the matrix polymer, although some clusters or agglomerated particles were also detected. Unlike the hybrids containing IMD-MMT, the clay layers of the C12PPh-MMT hybrid fiber were more dispersed into the matrix polymer. The thermal stability and tensile properties of the hybrid fibers increased with increasing clay content for DR = 1. However, as DR increased from 1 to 9 the ultimate strength and initial modulus of the hybrid fibers with IMD-MMT increased slightly whereas those of C12PPh-MMT hybrid fibers decreased slightly. (c) 2006 Wiley Periodicals, Inc.