Microstructural features of carbon fibres based on both polyacrylonitrile (PAN) and mesophase pitch (MP) are discussed in relation to their compressional performance estimated by the recoil test. The compressive strength of carbon fibres is influenced by a combination of various structural features and not by any single feature. In particular, the compressive failure strength increases linearly with increasing amounts of both inter- and intracrystalline disorder. For a given amount of disorder, the more recently developed PAN-based fibres exhibited much higher compressive failure stresses than older PAN- and MP-based carbon fibres; this is due to the more homogeneous distribution of microstructural features. In order to promote compressive strength it is suggested that all crystallite dimensions should be limited to below 5 nm whilst maintaining good orientation.

For both polyacrylonitrile homopolymer and copolymers(homo- and co-PANs) prepared in dimethylsulfoxide(DMSO) solution by radical polymerization induced by azo-bis-isobutyronitrile(AIBN), the thermal behavior studied via DSC technique was discussed in relation to the characteristics of polymers. It has been found that for the non-isothermal stabilization of homo-PANs under nitrogen and air atmospheres. the initiation and the maximum temperatures for the stabilization are not influenced by molecular weight and molecular weight distribution characteristics of polymers. However, under isothermal stabilization under air, longer time is required by the polymers with higher content of high molecular weight fraction, i.e. Mw > 3x10^5. It has also been confirmed that the addition of comonomer and air atmosphere favour the stabilization of polymers by lowering the intiation temperature, slowing down the reaction rate, and extending the temperature range within which the stabilization may be completed. From the isothermal stabilization of co-PANs. it was believed that the temperature of 240oC have practical significance.

For both homo-and co-polyacrylonitriles(homo- and co-PAN) prepared in dimethylsulfoxide(DMSO) solution by radical polymerization induced by azo-bis-isobutyronitrile(AIBN), the reaction kinetics was studied. It has been found that the polymerization rate increases with increasing concentrations of monomer and initiator, and the polymerization temperature, while molecular weight, polydispersity, and high molecular-weight-fraction(over 3x10^5 in Mw) decrease.

The polymerization factors to meet the desired physical properties of  polyacrylonitrile (PAN) spinning dope for on-line spinning were examined, The spinning dope was prepared by solution polymerization in dimethylsulfoxide solution induced by azobis-iso-butyronitrile. The physical properties of the spinning dope could be controlled by manipulating monomer concentration, initiator concentration, and polymerization temperature. At the unusually high monomer concentrations, required in the on-Iine spinning process, the polymerization of PAN exhibited a little deviation from the theoretical prediction

The distribution of microvoids in high-strength aramid fibre has been established. The tensile and compressive behaviours of both untreated and silver sulphide-impregnated Kevlar 981 fibre are reported and the results are discussed in terms of the influence of microvoids on the mechanical performance.

Modified polyethylene terephtale (M-PET) was obtained by copolymerizing dimethyl terephtalate(DMT), ethylene glycol, and dimethyl 5-sulfoisophthalate(DMS) and antistatic polyester material has been prepared by exposing M-PET containg ferric chloride to pyrrole vapor. The DMS component in M-PET was confirmed by the analysis of IR and NMR spectra. The formation of polypyrrole(PPy) in M-PET matrix was also confirmed by the analysis of IR spectrum. The changes of physical structure due to the insertion of ferric chloride and formation of PPy in M-PET have been investigated by analysing wide-angle X-ray diffraction curves. The surface of the antistatic polyester film showed the continuous phase of granular PPy which was formed through the film thickness The physical properties of antistatic polyester was satisfiable, that was, the tensile strength and the elongation at break retained 80 and 90% of those of M-PET matrix, respectively. But the modulus retained about 60% of M-PET matrix.