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This focus review describes a novel research concerning horseradish peroxidase (HRP)-mediated enzymatic polymerization under aqueous heterogeneous conditions as follows: (i) monodisperse polymer particles were prepared by enzymatic miniemulsion polymerization using surfmer (surfactant+monomer). (ii) Polymer particles stabilized by β-diketone moieties were prepared by enzymatic emulsifier-free emulsion polymerization. (iii) A novel method of surface-initiated enzymatic graft polymerization was used to synthesize core-shell particles.
This paper reviews the development of zincate-complex metathesis polymerization (ZCMP) and its application to protection-free direct synthesis of poly(3-(6-hydroxyhexyl)thiophene) as well as block copolythiophene. The modified ZCMP system using Ni(dcpe)Cl2 as a catalyst accomplished the preparation of well-defined poly(3-hexylthiophene)s (P3HTs) (Mn up to 35 000 g mol−1) with extremely low PDI (1.03∼1.11). In addition, the first example of all-conjugated block copolythiophene, P3HT-b-poly(3-octadecylthiophene), could be synthesized on the basis of the sequential monomer addition approach based on ZCMP.
Partially crosslinked poly(diphenylacetylene) (3a) bearing silanol groups were synthesized by the treatment of the membrane of 2a with n-Bu4N+F−. Imidazolium salt-containing poly(diphenylacetylene) (3b (Br−)) was obtained by the substitution of 1-methylimidazole to the membrane of 2b. Sulfonation of 2c gave a sulfonated poly(diphenylacetylene) (3c). The membrane of 3a was found to exhibit high gas permeability irrespective of the presence of the polar silanol groups in the polymer. Introduction of 1-methylimidazole into the membrane remarkably increased the CO2/N2 selectivity (PCO2/PN2=31–44). The sulfonated polymer 3c exhibited high CO2 permselectivity, and the PCO2/PN2 was as large as 54.
Theoretical and/or Monte Carlo studies are made of dilute solution properties of semiflexible stars and rings based on the Kratky–Porod wormlike chain model. The behavior of the properties in the range of the crossover from the rigid limit to the random-coil one is clarified. It is shown that effects of chain stiffness affect largely the dilute solution behavior not only of linear polymers but also of stars and rings, and are still remarkable even for typical flexible polymers with large molecular weight (∼105).
Enhancement in miscibility of the crystalline/crystalline blends of poly(butylene succinate)/poly(ethylene succinate) (PBS/PES) by simple melt annealing and their crystallization process are discussed. Immiscible PBS/PES blends changed into miscible blends when annealed at 150 °C. The enhancement in miscibility should be caused by transesterification between PBS and PES, which results in the formation of PBS–PES copolyesters. In the miscible annealed blends, both PBS and PES crystallized and showed the formation of interpenetrating spherulites, that is, the spherulites of one component growing inside of those of the other component.
It was found that the γ-ray-induced grafting of AAm on PET film is considerably facilitated by hot DMSO pretreatment. The DMSO pretreated PET films exhibit noticeable surface morphological changes including micropore creation, which is hypothesized to promote the AAm grafting.
The antibacterial studies on low-density polyethylene–chitosan films showed that a distinct inhibitory zone is developed against Staphylococcus aureus. The inhibitory zone diameter has been found to increase with increase in dielectric constant (ɛr) of the samples. The increment in ‘ɛr’ is due to the increase in orientation and interfacial polarizations by the presence of polar NH3+ ions in chitosan. Owing to the same reason, the inhibitory zone diameter increase in antibacterial studies. It is the first attempt to correlate dielectric and antibacterial properties of a polymeric material for food packaging applications.
A new method for the quantitative analysis of an epoxy resin dispersion by infrared spectroscopy was described. The absorbance ratio of various peaks in different areas of the IR spectra of a resin mixture is applied to evaluate the conditions for epoxy resin dispersion. The standard deviations of the absorbance ratios in various regions of the spectra enabled quantitative evaluation of the epoxy resin dispersion.
