The mechanism of the solid state phase transitions in the polydiacetylene, poly-4BCMU: thermal, X-ray diffraction and Raman scattering studies

Photopolymerization of Thin Polycrystalline Diacetylene Films and Quenching of the Precursor Excited State

“…In the BCMU family at least, the stable electronic structure of the chains is blue if n is odd and red if it is even, and it has been suggested that this is due to the parity of the spacer group favoring or not a planar conformation of the chain. Note that the poly nBCMU chains produced by polymerization of a crystal may be blue (as in the case of 4B), the red form being obtained for n even either by dissolution and reprecipitation of the polymer or by melting the polymer crystal, , or possibly upon thermal annealing of the solid phase. (A study of this color transition in the same 4B films as used in the present study is in progress.…”

Dissolution and Spectroscopic Properties of the Polydiacetylene Poly(10,12-docosadiyne-1,12-diol-bisethylurethane)

“…[48] This is above the first solid-state transition of the polymer crystals. [42,55] Rubbed films of 9BCMU and 9EU were heated to 130 and 170 8C; these temperatures were chosen to be just above those of the solid-state and melting transitions of 9BCMU crystals, respectively. [42] Heating to 130 and 170 8C produced a more ordered red-phase for 9BCMU (Figure 4 (a) and 5 (a)) with a sharper absorption peak with a maximum at 535 nm (18 700 cm -1 ) compared to 529 nm (18 900 cm -1 ) in the original film.…”

Photostabilisation of an omniphobic, drop-castable surface coating by transformation of a self-assembled supramolecular xerogel into a covalent polymer xerogel

“…25,34 Although the structural changes during the polymerization process are usually small, the polymerisation is accompanied by a slight contraction of the bulk material which sometimes results in mechanical stress in the solid that can lead to cracking. [35][36][37][38][39] Fig. 1a depicts a fluorous LMWG design on the basis of the well-established diacetylene-diamide gelator motif.…”