THERMAL AND SPECTROSCOPIC PROPERTIES OF THE POLYDIACETYLENE DERIVED FROM DOCOSA-10,12-DIYNE-1,22-DIYLBIS(PHENYLACETATE)

Polydiacetylene (2) of varying molecular weight has been formed by UV- or Co-60 gamma-irradiation of the diacetylene PhCH(2)CO(2)(CH2)(9)-C= C-C=C(CH2)(9)O(2)CCH(2)Ph (3), with conversions of 30- > 95%. Samples of (2) with differing physical properties have been studied, in the bu lk phase, by CPMAS C-13 NMR and VIS/UV spectroscopy and by DSC; comple mentary spectroscopic data on solutions of (2), including fluorescence studies, are also reported. Spectroscopic studies support the presenc e of an extended planar conjugated backbone in 'as polymerised' blue-b lack samples of (2), from which various forms of red-coloured polymer, with shorter conjugation lengths, can be obtained. Studies of the the rmal behaviour indicate the existence of several differing thermal tra nsitions for these materials and the results are discussed.