Recent Achievements in Structure Ordering and Control of Properties of Para-Aramide Fibres

Abstract

The family of commercially produced high-strength, high-modulus fibres and yarns for the manufacture of technical textiles and construction composites, based on aromatic para-polyamides – poly-para-phenylene-terephphtalamide (Kevlar, Twaron), copolymers (Terlon, Technora), poly-para-heteroarylenes (SVM, Armos), was discussed and compared in the paper. The necessity of drawing such a comparison resulted from the fact that although there were papers on individual para-aramide fibres, but no comparative analysis of their structure and properties was performed yet. Therefore the main para-aramide fibres, their structure and its optimisation, their properties and ways of controlling these properties were reviewed in the paper. While discussing the main features of para-aramide fibres the following indices were taken into account: optimal molecular polarity and rigidity, energy of interatomic and inter-molecular interactions, 3-D regularity, axial orientation, equal length of molecular chains in amorphous regions, etc. A special attention was paid to Armos® fibres manufactured by J.S. „Tverkhimvolokno” Company because they have several advantages over other para-aramide fibres as concerns mechanical and thermal properties. Currently J.-S. „Tverkhimvolokno” Company manufactures Armos® yarns and roving with tenacity higher than 4.5 – 5.0 GPa and elasticity modulus over 145 GPa.