The ring-opening polymerization of glycidyl phenyl ether (GPE) and an epoxy curing reaction of bisphenol A diglycidyl ether (BADGE) were performed with metal-free tetra-n-butylammonium halides (TBAX); the anions included fluoride, chloride, bromide, and iodide. We compared the extent of polymerization achieved as a result of using different TBAX as initiators. The comparison revealed that tetra-n-butylammonium fluoride (TBAF) was the most efficient initiator for both the polymerization of GPE and the epoxy curing reaction of BADGE.

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SynopsisNetwork polymers of poly(acrylic acid) cross-linked with elastin-like peptide(PAA-ELP(n%), n% : degree of crosslinking) were newly designed and synthesized to fabricate dual-responsive polymer materials. The polymerizable ELP as a cross-linker, which contains methacrylamide group at both chain ends, was first prepared by solid-phase synthesis using Fmoc chemistry, and then two types of network polymers(PAA-ELP(1%) and (2%)) were successfully obtained by radical copolymerization of this ELP and acrylic acid. Temperature－dependent structural and assembling properties of these polymers in water were examined by using CD and turbidity measurements. PAA-ELP(1%) showed a phase transition with upper critical solution temperature, based on the conformational change of the ELP segment from random coil to ordered structure involving type II β-turns along with the temperature rise. On the other hand, PAA-ELP(2%) was found to form hydrogel and to give a marked temperature－dependence of the swelling ratio at neutral pH region close to the pK_a of PAA segment. This hydrogel was also found to transform gradually to a sol state by cleaving peptide bonds of the ELP segment with papain as a peptide segment cleavable enzyme.(Received August 10, 2010)

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SynopsisHeat-resistant and optical coating films were synthesized with fluorinated silsesquioxane having surface reforming ability based on the double-decker shaped structure. Surface, optical, and thermal properties were evaluated by contact angle measurement, UV-vis spectroscopy, and thermal gravimetric analysis, respectively. In this study, we confirmed the following points; (1)Surface free energy of the films can be controlled by addition of a small amount of fluorinated silsesquioxane.(2)The coating films were superior in transparency and have little absorption in near ultraviolet region, so that the film had stability against ultraviolet irradiation. (3)Decomposition temperature of these films was higher than 300℃. (4)The bulk properties were not influenced by addition of fluorinated silsesquioxane. Through this study, the coating films composed of fluorinated silsesquioxane derivatives are expected to give a novel hybrid films superior in transparency and heat resistance.

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SynopsisToughening of cyanate ester resin was carried out by simultaneous curing of cyanate ester resin with radical copolymerization of N-phenylmaleimide, styrene (St) and divinylbenzene (DVB). The influence of radical polymerization on curing behavior of cyanate resin matrix was also studied. The introduction of DVB as a crosslinking agent increased miscibility of the cyanate ester matrix with the modifier, and thereby the fracture toughness for the modified cyanate ester resin was increased by 77% with keeping good flexural properties and high glass transition temperature, compared to the unmodified resin, when 10wt% of N-phenylmaleimide/St (1/1, mol/mol) and DVB (5mol% of the modifier) were added.The observation of phase separation of the modified resins by AFM revealed that toughening was accomplished by the morphology with the modifier-rich phases of 200 to 300 nanometers dispersed in the cyanate ester-rich matrix. Then, from the results of DSC and IR measurements, we found that radical polymerization of PMSD modifier was finished before curing process of 150℃/1h and did not interfere with curing of the cyanate resin matrix each other.

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SynopsisDiallyl phthalate resin is used as coatings for electronic devices and electric parts, requiring high reliability under long-term adverse environmental conditions because of their excellent properties. However, the use of diallyl phthalate resin is restricted because of poor adhesive properties to various metals and brittleness. We synthesized various modifiers and added them in diallyl phthalate resin, and blended epoxy resin in diallyl phthalate resin, to improve adhesive property and toughness of the resin. In this report, the study about the modification of diallyl phthalate resin that authors performed was reviewed.(Received August 18, 2010)

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[in Japanese]

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