CHEMISTRY AND TECHNOLOGY OF CHEMICAL FIBRES RUSSIAN ARAMID FIBRES: PAST - PRESENT - FUTURE*

摘要

The history of development of domestic technologies for the manufacture of heat-resistant, high-strength, and high-modulus SVM (superhigh-strength and high-modulus), Armos, Rusar, Rusar-S, and Rusar NT aramid fibres is reviewed briefly. The properties of theses fibres at the beginning of their manufacture and now are adduced. The results of the study of the surface and cross-sections of aramid monofibres of the same chemical composition (Armos, Rusar, and Rusar-S) employing scanning electron, atomic-force, and transmission electron microscopy show that these fibres can be assigned to the class of nanomaterials. It is demonstrated that dry-wet spinning of fibres from isotropic polymer solutions is a technique that makes it possible to change the roughness and, consequently, reduce the imperfection of the monofibre surface at the nanolevel and at the same time enhance the strength of the fibre. Photomicrographs of the monofibre cross-section show that aramid fibre is a composite consisting of agglomerates of fibrils measuring 10-15 nm. Their diameter does not depend on the polymer concentration in the spinning solution and seems to be dependent on the thermodynamic conditions of precipitation of the initial solution. The authors believe that further improvement in the array of properties of domestic aramid fibres should follow the path of adapting dry-wet spinning technique to commercial manufacture in combination with use of the chemical composition of the fibre-forming polymer through mastering of manufacture of MD type of new monomers.