In this study, the swelling behavior of a konjac glucomannan (KG) /κ-carrageenan (CA) mixed gel was investigated for examining its possibility as a new type of material for an actuator. Volume changes of a KG/CA mixed gel have been studied with reference to the effects of solvent, pH and temperature. The rectangular specimen (10×30×3mm³) containing 2.0 wt% KG/CA was prepared by adding 0.3 wt% of Ca (OH) ₂, and immersed in distilled water containing different concentrations of acetone (0-50vol%) at 20-60°C. The changes in volume for different values of pH 0-13 were also examined in NaOH and HCl aqueous solutions. In aqueous acetone at a concentration below 20 vol%, the specimens were swollen in a short time at all temperatures. In the solutions containing acetone above 40 vol%, the specimens always shrank. At 50°C the equilibrium swelling ratios were generally lower than those at 40°C. Effect of pH was then examined, and high swelling in aqueous solutions was observed at pH about 5 and 10. It may be concluded that the KG/CA mixed gel is an amphoteric gel which can strongly respond to both acidic and basic functional groups of environment.

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Native woods such as SUGI and NARA were found to become lighter in weight and more porous by treating with the hydrogen sulfide-type artificial hot spring water (AHS-water) prepared by dissolution of Yubana (deposits of natural hot spring water from Matsukawa in Iwate prefecture) in hot distilled water, while almost the same result was obtained by using H₂SO₄ solution as reference. However, absorption ability for moisture of AHS-water treated woods was higher than that of H₂SO₄ treated woods. Also, XRD analysis indicates that the crystallite width of the woods expands and the crystallite length decreases with the elapse of the treating time. But the crystallinity of AHS-water treated woods was higher than that of H₂SO₄ treated woods. It was thought to depend on dissociation for molecules of the crystallite and hydrolysis for folded chains of the crystallite. Thus along with the treatment with AHS-water, the reconstruction of molecule chains would occur and would lead to a larger size of the crystallite growth. This is due to the formation of coordination bonds between Fe ions in AHS-water and OH groups of cellulose.

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The electric field induced strain-electrostrictive response-of polyurethane elastomers (PUEs) was experimentally investigated. The electrostriction measuring method without experimental errors from the flexure motion and the mechanical constrains for flexible samples, such as a rubber whose modulus is from 10⁶Pa to 10⁷Pa, was established using 400Pa-loaded samples and completely constrained samples, and the electrostriction coefficients of the samples were compared. The influence of microphase separation on the electrostriction coefficients was investigated in PUEs prepared from poly (ether glycol) s, such as polyoxytetramethylene glycol, polyoxypropylene glycol, and polyoxy-1, 2-butylene glycol, 1, 4-butanediol (1, 4-BD), trimethylolpropane (TMP), and 4, 4'-diphenylmethane diisocyanate (MDI). The molar ratio of a poly (ether glycol), 1, 4-BD, TMP, and MDI was 1: 0.8: 0.13: 2. PUEs with hard segment aggregates of poor order were obtained at a high curing temperature (180°C). PUEs cured at 180°C had much larger electrostriction coefficients than those cured at 100°C. The results showed that making order of hard segment aggregates poorer is a very useful way for the improvement of electrostrictive effect in PUE with the same composition.

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First, the cyclic depsipeptides were synthesized from an amino acid (L-alanine) and hydroxy acid derivatives. The hydroxy acid derivatives used were chloroacetyl chloride, DL-2-bromopropionyl bromide, and DL-2-bromo-n-butyryl bromide. The depsipeptides obtained were abbreviated to L-MMO, L-DMO, and L-MEMO, respectively, in the order of the hydroxy acid derivatives. The yields of these depsipeptides were in order of L-MMO<L-DMO<L-MEMO, depending on the difficulty in the cyclization of their precursors (linear amides). We have prepared homo- and copolymers of depsipeptides and ε-caprolactone (CL) using tin (II) octylate [Sn (Oct) ₂] as a catalyst. The reactivity (polymerizability) of depsipeptide monomers decreased in the order: L-MMO>L-DMO>L-MEMO (the L-MEMO homopolymer was not obtained). This is probably due to the ease of coordination of these monomers to Sn (Oct) ₂ catalyst. The thermal properties and NMR spectra of depsipeptide/CL copolymers revealed that these copolymers had random sequences. Finally, we have examined the biodegradability of the copolymers by enzymes (cholesterol esterase, Proteinase K) and activated sludge. The degradation of the copolymers by the esterase was not very high, and was little affected by the hydroxy acid unit of depsipeptide. But, the degradability of the copolymers by Proteinase K and activated sludge was considerably greater than that of CL homopolymer, and was in the order: coply (L-MMO/CL) <copoly (L-DMO/CL) <copoly (L-MEMO/CL). From the changes in some properties (molecular weight, composition, thermal properties) of copolymers before and after degradation by Proteinase K, it has become apparent that noncrystalline parts containing more depsipeptide in the copolymers were degraded preferentially. The measurement of the mechanical properties of the polymers indicated that these depsipeptide/CL copolymers have much the same tensile strength as that of high density polyethylene.

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Linear low-density polyethylene (LLDPE) in methylcyclohexane, ethylbenzene, and isooctane converts to a thermally reversible gel. In this study, crystalline junction size ζin a LLDPE gel was estimated from gel-melting temperature, and the effect of gelation solvent on the size ζ was discussed from the interaction parameter (χ) between polymer and solvent. It was found that the junction size ζ measured in a different solvent increased with increasing interaction parameter χ. Moreover, the size ζ measured in an identical solvent increased with increasing length of short chain branching.

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The pendant spacer-separated aliphatic primary amines of polyoxetane resins were modified by polymer reactions to give chelate resins bearing N-spacer-substituted aspartic and its hydroxamic acid moieties. The primary amines of polyoxetane resins were subjected to the Michael addition with diethyl maleate to a degree of functionality of 0.6-0.9, and the resultant aspartates were then converted to the acid moieties by alkali-hydrolysis or NH₂OH-aminolysis. The corresponding anilino pendants also gave the Michael addition products, as confirmed by their IR spectra, although a model product was not obtained. The Cu (II) -adsorption capacities of the acid-containing aliphatic amino-type resins were 2.9-3.8mmolg^-1, which were higher than the capacity expected for the ordinary structure of a Cu (II) ion chelated with two molecules of carboxylic or hydroxamic acids, being ascribed to the expansibility of a polyoxetane network and the hydrophilicity of the pendant acids.

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Nylon filaments (φ=0.9mm) were dyed with two different disperse dyes, one of which is an azobenzene-based dye and the other is an anthraquinone-based dye, at 40°C, 60°C, and 80°C, and the concentration gradients of these dye molecules penetrated along and perpendicular to the fiber axis were measured by optical microscopy and microspectrophotometry. The concentration gradients thus obtained were plotted on a profile of relative dye concentration (=absorbance) as a function of penetrated distance attained by the dye molecules under given conditions and compared with each other. In parallel to the above, swelling behavior of nylon 6 filaments during the course of this dyeing process was also traced by measuring the change of diameter of the cross-sections of the filaments. The nylon 6 filament showed a remarkable swelling in the dye bath at 80°C, for example, as high as 8% increase in diameter. In the case of nylon 6-disperse dye systems, the profiles showed that the relative dye concentration at the periphery of the filament is lower than that of interior part of the same sample, and this tends to increase with increasing the time over a period examined. To elucidate this phenomenon, the same experimental procedures were applied to nylon 6-acid dye systems at 80°C and further to poly (ethylene terephthalate) filaments (φ=1.6mm and 1.1mm) -disperse dye systems at 120°C.

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In this study, we describe results of syntheses and biodegradability studies of aliphatic polyestercarbonates derived from dimethyl succinate, 1, 4-butanediol and third components such as carbonates. NMR data showed the polycondensation of dimethyl succinate, 1, 4-butanediol with carbonates gave polyestercarbonates containing carbonate units. Their molecular weight (M_n) was about 30000, and the melting points were between 51-118°C. When the carbonate ratio of aliphatic polyestercarbonate is low, the biodegradability values of the aliphatic polyestercarbonate correlated with their crystallinity (enthalpy of melting) values. But the carbonate unit ratio at the lowest enthalpy of melting was larger than the ratio which showed the highest biodegradability of the polyestercarbonate. Increasing in the carbonate unit led to a decreasing in crystallinity of the polyestercarbonate. But the biodegradability of the carbonate bond is lower than that of ester bond. Therefore, we suggest that the reason why the two factors: the biodegradability and the crystallinity of the polyestercarbonate, do not correlate is due to the difference of biodegradability between carbonate bond and ester bond. Microbial degradation test by soil extraction method that used microorganisms taken from the soil showed that biodegradation of polyestercarbonate was accelerated remarkably compared to that of the homopolymer. This result obtained by the soil extraction method correlated with the results of soil embedded method and enzymatical method. The soil extraction method can be expected as a rapid test method compared to the soil embedded method.

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