Thermally induced solid‐state reactions and microstructure changes in a high molar mass, semicrystalline, aromatic diacetylene‐containing polyester, poly[2,4‐hexadiyn‐1,6‐ylene terephthalate], were investigated with a combination of laser Raman spectroscopy, differential scanning calorimetry, and wide‐angle X‐ray diffraction analysis. The study has provided some new insights into the rather complex solid‐state reactions in the semicrystalline diacetylene‐containing polyester. Results suggest that, in addition to the usual desired solid‐state topochemical crosspolymerization in the crystalline region, a certain degree of random crosslinking reaction occurs in the amorphous region, especially when the annealing is carried out above the glass transition. After prolonged annealing or annealing at a higher temperature, a further reaction involving the formed polydiacetylene chains may occur, as evident from the reduction in crystallinity and even complete loss of crystallinity. An attempt has been made to separate the contribution of the topochemical reaction from the overlapping exothermic activities in the differential scanning calorimetry curves via subtraction. This allows the monitoring of the crystalline‐phase solid‐state topochemical crosspolymerization. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 2354–2363, 2002

During polarization treatment, the residual polarization electric field generated by BaTiO3 increased Ebi of the cells and width of the depletion layer, promoted extraction and separation of carriers, and improved photoelectric performance of PSCs.

A series of novel polyesters containing conjugated diacetylenes (DA-polyesters) were prepared from various diacetylene diols with/without methyl side groups and isomers of aromatic acid chlorides via an interfacial condensation. A fully aliphatic DA-polyester was also prepared for comparison. All synthesised DA-polyesters are soluble in m-cresol, and the intrinsic viscosities were measured. In addition, compact and coherent films and sheets can be obtained from some of the polymers via solution or melt casting. The structure, morphology, and properties were characterized using spectroscopic methods, including FTIR, Raman, and WAXD and thermal analysis including TGA, DSC techniques. DMA was carried out on the solution-cast thin films and melt-processed samples. Close correlation was found between the structure and properties in these DA-polyesters. In particular, through analysis using isothermal DSC and Raman spectroscopy, the solid-state reactivity of the diacetylene groups in these polyesters was found related to the interchain spacings, which are, in turn, controlled by the molecular structure of the polymers. Results have shown that the aliphatic DA-polyester behaves very differently compared to the aromatic ones. Distinct differences were also observed among meta-and para-disubstituted isomers of the DA-polyesters. Furthermore, the introduction of methyl side groups has dramatically affected the thermal and thermal mechanical behavior by altering the interchain spacing of the polymers.

A series of novel polyesters containing conjugated diacetylenes (DA‐polyesters) were prepared from various diacetylene diols with/without methyl side groups and isomers of aromatic acid chlorides via an interfacial condensation. A fully aliphatic DA‐polyester was also prepared for comparison. All synthesised DA‐polyesters are soluble in m‐cresol, and the intrinsic viscosities were measured. In addition, compact and coherent films and sheets can be obtained from some of the polymers via solution or melt casting. The structure, morphology, and properties were characterized using spectroscopic methods, including FTIR, Raman, and WAXD and thermal analysis including TGA, DSC techniques. DMA was carried out on the solution‐cast thin films and melt‐processed samples. Close correlation was found between the structure and properties in these DA‐polyesters. In particular, through analysis using isothermal DSC and Raman spectroscopy, the solid‐state reactivity of the diacetylene groups in these polyesters was found related to the interchain spacings, which are, in turn, controlled by the molecular structure of the polymers. Results have shown that the aliphatic DA‐polyester behaves very differently compared to the aromatic ones. Distinct differences were also observed among meta‐ and para‐disubstituted isomers of the DA‐polyesters. Furthermore, the introduction of methyl side groups has dramatically affected the thermal and thermal mechanical behavior by altering the interchain spacing of the polymers. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 965–974, 1999