Abstract: A photorefractive (PR) device comprises of a layer of a novel photorefractive polymer composite sandwiched inbetween two transparent electrodes. The PR polymer composite comprises a photoconducting polymer, a photosensitizer, a novel second-order, non-linear optical chromophore, and a plasticizer in an amount sufficient to provide the PR polymer composite with a glass transition temperature below about 45.degree. C. The PR polymer composite is capable of internally storing image patterns generated by interfering two coherent light beams inside the material. The PR polymer composite shows high diffraction efficiencies (near 100%) and high net two-coupling gain (>200 cm.sup.-1). The writing of information is reversible. Consequently, the device is suitable for read/write holographic storage and real-time image processing applications, and is capable of being poled at essentially room temperature.

Abstract: In the two stage reaction of terephthalic acid with 1,4-butanediol to produce polybutylene terephthalate in which acid and diol are first subjected to catalytic esterification/oligomerization and the resulting products are thereafter subjected to catalytic polycondensation, the co-production of tetrahydrofuran is significantly reduced by conducting the polycondensation reaction prior to completion of the esterification/oligomerization reaction.

Abstract: In the two stage reaction of terephthalic acid with 1,4-butanediol to produce polybutylene terephthalate in which acid and diol are first subjected to catalytic esterification/oligomerization and the resulting products are thereafter subjected to catalytic polycondensation, the co-production of tetrahydrofuran is significantly reduced by conducting the polycondensation reaction prior to completion of the esterification/oligomerization reaction.