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Synthesis of zinc oxide nanoparticles in the core of reverse micelles of poly(methyl methacrylate)-block-poly(acrylic acid) (PMMA-b-PAA) in toluene, and succeeding hybridization with poly(methyl methacylate) (PMMA) to fabricate transparent hybrid films was investigated. Inclusion of a ZnO precursor into the cores of the reverse micelles formed in toluene was carried out by addition of diethyl zinc, and heating the resulting solution to 125°C in an autoclave to form ZnO that formed crystals. Fabrication of ZnO/PMMA hybrid films by a casting method using a mixed solution of the reverse micelles and PMMA resulted in low transparency films due to aggregation of ZnO nanoparticles during film forming. Freeze drying of the reverse micelle solution to prepare a ZnO/PMMA hybrid powder and succeeding hybridization with PMMA by hot-pressing at 150°C and 20 MPa gave highly transparent ZnO/PMMA hybrid films, refractive indexes of which were coincident with calculated values. TEM images showed small domains of PMMA and domains containing ZnO nanoparticles. [ABSTRACT FROM AUTHOR]

The crystalline hard segment models of segmented polyurethane elastomers are made of 4,4'-diphenylmethane diisocyanate (MDI) and 1,4-butanediol (BD). Here we investigate the crystalline behavior of polyurethane that in addition contain 1,1,1-trimethylol propane (TMP), poly(oxytetramethylene) glycol (PTMG), and polyethylene glycol (PEG). The melting points (Tm) of crystallized MDI-BD units decreased with increasing TMP contents and increased with increasing PTMG contents, respectively. A decrease in molecular weight of PTMG and incorporation of PEG decreased Tm. These results indicate that incorporation of a third component would cause to form the well-ordered crystal being closed to equilibrium state. [ABSTRACT FROM AUTHOR]