Diacetylene thermal annealing

The similar main chain structures with conjugated diacetylene units (34, 35) can be prepared (equations 32 and 33) by polyaddition or polycondensation using components containing the conjugated diyne units . The processable polymers become insoluble on photoirradiation or by thermal annealing via intermolecular cross-linking. 

A spacing of the diacetylenes is much closer to that anticipated for the polymer (4.9 A) and the distance between the reacting carbon atoms of adjacent diacetylenes is within van der Waals contact (3.38 A). On standing at room temperature or by thermal annealing over night at 110 °C the crystals of the diacetylene were converted to the polydiacetylene [17]. 

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