MECHANICAL-PROPERTIES OF DIACETYLENE FUNCTIONALIZED POLYAMIDES

An aliphatic diacetylene functionalized polyamide has been synthesized and successfully processed into high quality fibres and films for mechanical property measurements. The reactive diacetylene functional groups positioned in the backbone of this polymer remained dormant during a wide variety of processing schemes but were activated in a controlled manner by exposure to fixed dosages of high energy electrons. Solid state C-13 nuclear magnetic resonance revealed that exposure to high energy electrons crosslinks the polymer via the formation of conjugated polydiacetylene chains. In general, crosslinking via the formation of polydiacetylene chains was found to increase the ultimate tensile strength and modulus of the material and reduce its critical failure strain. For specific fibres, the tensile strength of the material was doubled, its modulus increased by 50%, and the failure strain only reduced to 30% thereby maintaining a high degree of toughness in this system even after an 80 Mrad dose of electrons.