Terpolymers were synthesized by graft copolymerization of acrylamide (AAm) and tri-n-alkyl-4-vinyl benzyl phosphonium chloride (TRVB) on poly (vinyl alcohol) (PVA), and following crosslinking with glutaraldehyde (GA). Four vinyl phosphonium monomers having various alkyl groups, such as tri-n-ethyl- (TEVB), tri-n-butyl- (TBVB), tri-n-hexyl- (THVB), and tri-n-octyl-(TOVB), were used as TRVB. Swelling behavior and antibacterial activity against Staphylococcus aureus (S aureus) of the terpolymers were examined.
Swelling ratio increased with increasing content of TRVB, and decreased with increasing alkyl chain length of TRVB in the terpolymers, as well as increasing concentration of GA during crosslinking. The antibacterial activity of the terpolymers increased with increasing content and alkyl chain length of TRVB in the terpolymers. These results imply that the antibacterial activity is depended on the electrostatic interaction and hydrophobic interaction between the terpolymers and bacteria.

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New phenolic polymers were prepared by the addition-condensation of p-hydroxycalix [6] arene with paraformaldehyde under acidic or basic conditions. In the reaction, the ortho positions to a phenolic hydroxyl group at the upper rim in p-hydroxycalix [6] arene readily reacted with formaldehyde, in the same manner of phenols. The polymers were characterized by IR and ¹H-NMR, and gel permeation chromatography (GPC). The polymer contained the cone-like conformation of p-hydroxycalix [6] arene in the chain. In the co-condensation of p-hydroxycalix [6] arene and various phenols (i.e., phenol, hydroquinone, p-cresol, and p-tert-butylphenol), the reactivity of phenolic unit in p-hydroxycalix [6] arene was higher than that of phenols. In addition, the differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were done for the polymers and it was found that the insoluble polymer in acetone showed a greater thermal stability, due to a high degree of cross-linking.

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This study is to elucidate the process of network formation of a photosensitive poly (vinyl alcohol) with pendant styrylpyridinium groups. The fluorescence intensity ratio, I₅₁₀ (excimer) /I₄₂₇ (monomer) for the model compound as well as the 4-styrylpyridinium compound in solutions rapidly increases above a concentration of 5-8 X 10^-2mol 1^-1, whereas the values of surface tension decrease rapidly. The compounds in aqueous solution associate to form pre-micellar aggregates. In PVA-SbQ aqueous solution, the I₅₁₀/I₄₂₇ increases with increasing number of SbQ groups, and mainly intermolecular excimer is formed at a polymer concentration above 1.1g dl^-1.
From observation on the UV-visible spectra of films (4μm) prepared by the solvent evaporation of 7wt% PVA-SbQ aqueous solution, the lower the drying temperature the higher is the probability of formation of dimers. This result suggests that the formation of ground-state aggregates or dimers is induced by slow-converting hydrophilic SbQ groups into hydrophobic SbQ groups.
The films having SbQ groups give a higher Tg than that of a PVA film because of an increase of molecular packing density of amorphous regions. The reason is believed to be caused by the formation of aggregates, and the tendency becomes progressively higher as the content of SbQ groups increases.

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The creep test of an epoxy-resin during irradiation was carried out at a cryogenic temperature. Creep deformation during irradiation was observed to be enhanced in comparison with those on a post-irradiated one. In order to clarify the mechanism of the radiation-induced creep, measurements of electron spin resonance (ESR) and solvent swelling of specimens have been performed. Radicals increased with the dose from the observation of ESR. Chain scission increased with the dose from the result of the swelling observation. The increase in the radicals corresponds to the increase of the chain scission. The mechanism of increased deformation of the resin during irradiation is proposed to be caused by increased scission of chain on the release of the local strain energy.

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Enzymatic oxidative polymerizations of phenols afforded a new class of polyphenols. Controls of molecular weight, solubility, and shape have been achieved by selecting appropriate reaction conditions. The enzymatic production process of the polyphenols was extended to syntheses of crosslinkable polyphenols. Peroxidase-catalyzed polymerization of bisphenol-A produced a soluble polymer, which became insoluble by thermal treatment. The polymerization of a phenol derivative having a methacryloyl group proceeded chemoselectively to give the polymer having the methacryloyl group in the side chain. The resulting polymer was subjected to thermal and photochemical curings. Enzymatically synthesized poly (cardanol) was crosslinked in the presence of cobalt naphthenate.

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Toughening of epoxy resins is very important for the application of the resins as advanced specialty materials to aerospace, electronic, or automotive industries. This review has focused on a guiding principle in the toughening of epoxy resins. The method for the toughening is based on two categories : (i) toughening with high-performance epoxy resins or hardners; (ii) toughening with modifiers such as elastomers or thermoplastics. High-performance epoxy resins with rigid biphenyl, dicyclopentadienyl, or naphthalene residues have been developed and successfully used in microelectronic industry. The resins give the cured products with lower crosslinking density and higher toughness, compared to cresol novolac epoxy resins. Epoxy resins containing mesogen units give liquid crystaline thermosetts with high toughness.
Elastomers such as liquid rubbers are good toughening agents for epoxy resins with lowly crosslinked structure, but not for ones with highly crosslinked structure. The use of engineering plastics such as polysulfone, poly (ether sulfone), or poly (ether imide) can result in toughened epoxy resins without significant decreases in modulus, strengths, and thermal properties. The factors that affect the toughening of epoxy resins with engineering plastics have been discussed.

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