Polymerisation and characterisation of nitrile-terminated diacetylene materials

A family of nitrile-terminated diacetylene materials were synthesised. Samples were prepared in various forms and polymerisation was performed photochemically and thermally. The resulting materials exhibited low molecular weights and were obtained in low yields. Although the diacetylene group had oligomerised, no evidence was found in support of –C≡N-chain formation. Thermochromism was exhibited by the irradiated 8-nitrile sample and a molecular interpretation of this chromic transition was discussed. Diffraction data implied that strong intermolecular interactions were present between adjacent nitrile groups in the low temperature phase. It is suggested that stresses are built up during polymerisation, which cause the low degree of polymerisation and yield. The bibliography includes 72 references.