PLASTICIZATION OF CARBON FIBRES.

A technique for temporarily plasticizing high-modulus carbon fibers which offers promise for permitting familiar textile operations to be carried out on them without mechanical damage, consists in exposing the carbon fibers to a suitable material, such as bromine or iodine monochloride. These materials have the effect of plasticizing the fibers, perhaps temporarily lowering their modulus values. In the plasticized state, the yarns can be made to take various shapes including sharp bends. On removal of the plasticizer, the yarns will retain a portion of the shape imparted to them. Tensile properties of the yarn and flexural properties of composites obtained on yarn that has undergone bromination and debromination show no changes relative to the untreated samples.