Carbon fibres from mesophase pitch

Abstract

Carbon fibres derived from mesophase pitch have been available as continuous filament tow or yarn since 1974. By comparison with other carbon fibres, they are of the high modulus, moderate strength type but are different from those of other precursors in that they are significantly higher in density and are ‘graphitizable’ in that they develop three dimensional crystalline order at high temperatures. Recent progress toward elimination of structural flaws in both yarns and component filaments have resulted in improved levels of strength for fibres which possess a Young modulus of 380 GPa. Strand strengths of 2.4 GPa have been achieved and a still higher level appears to be a practical goal. Carbon fibres from mesophase pitch are capable of achieving a high Young modulus with inexpensive processing techniques and should, therefore, be uniquely suitable for all ‘modulus-critical’ applications. Ultimately, they may also possess the capability of achieving extremely high tensile strengths.