Dietary Guar Gum Reduces Lymph Flow and Diminishes Lipid Transport in Thoracic Duct-Cannulated Rats

Guar gum has a well-recognized hypolipidemic effect. This effect is thought to be due to the physicochemical properties of guar gum, which may cause changes in adsorption of lipids or the viscosity of the intestinal contents. Guar gum is a non-specific absorption inhibitor of any type of lipid-soluble compound. Permanent lymph duct cannulation was performed on rats to investigate the effects of dietary guar gum on lymph flow and lipid transport. Rats fed a 5% guar gum diet were compared with those fed a 5% cellulose diet, and lymph was collected after feeding. The water-holding capacity (WHC), settling volume in water (SV), and viscosity of guar gum were compared with those of cellulose. Rats fed with the guar gum diet had significantly lower lymph flow and lymphatic lipid transport than did rats fed with the cellulose diet. The WHC, SV, and viscosity of guar gum were significantly higher than those of cellulose. We propose that dietary guar gum reduces lymph flow and thereby diminishes lipid transport by means of its physicochemical properties related to water behavior in the intestine.     

Synthesis and polymerization of maleimide-type new macromonomer with polystyrene having controlled chain length

A new reactive and functionalized polystyrene with a maleimide moiety at the one polymer end was synthesized with N-(4-(1-chloroethyl)pheyl)maleimide (CEPMI)/SnCl₄/tetra-butylammonium chloride (TBAC) initiating system. The polymer obtained with the CEPMI/SnCl₄/TBAC initiating system under the condition of [TBAC]/[SnCl₄] = 1 was to be maleimide-type macromonomer with polystyrene having controlled molecular weight of polystyrene (VI). VI could be polymerized with anionic and radical initiators to give new type graft polymer (poly[N-(4-ethylphenyl)maleimide]-graft-polystyrene) with controlled chain length with respect to side chains.     

Polymer electrolyte membrane with nanomatrix channel prepared by sulfonation of natural rubber grafted with polystyrene

High‐proton‐conductive polymer electrolyte with a nanomatrix channel was prepared by graft copolymerization of styrene onto deproteinized natural rubber followed by sulfonation with chlorosulfonic acid. First, natural rubber latex was purified with urea in the presence of surfactant to remove almost all proteins present in the rubber. Second, graft copolymerization of styrene onto deproteinized natural rubber was carried out with tert‐butyl hydroperoxide/tetraethylenepentamine as an initiator at 30°C in latex stage. The graft‐copolymerized natural rubber (DPNR‐graft‐PS) was sulfonated with chlorosulfonic acid in chloroform solution at an ambient temperature. The resulting sulfonated DPNR‐graft‐PS was characterized by FTIR spectroscopy, solid state ¹³C CP/MAS NMR spectroscopy, elemental analysis, and transmission electron microscopy. High proton conductivity of about 0.1 S/cm, less water uptake of 24 wt % and comparatively good stress at break of 9 MPa were accomplished at suitable contents of styrene units and sulfur, i.e., 32 wt % and 75 mol %, respectively. The high proton conductivity, excellent stability, and good mechanical properties were associated with not only the formation of the nanomatrix channel but also a specific concentration of sulfuric acid group. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.     

Preparation of raspberry‐like poly(methyl methacrylate) particles by seeded dispersion polymerization

The facile preparation of nonspherical raspberry‐like poly(methyl methacrylate) (PMMA) particles by seeded dispersion polymerization of methyl methacrylate (MMA) on micron‐sized PMMA seed particles was described. Various polymerization parameters influencing the particle morphology, as well as the polymerization kinetic and morphological stability, were investigated in detail. It was found that the following polymerization conditions were necessary to prepare this kind of nonspherical particles: a relatively low temperature, an appropriate ratio of seed/MMA, an initiator with a relatively low decomposition rate, and a relatively low initiator concentration. These particles showed very good morphological stability at room temperature, but they changed to the spherical ones when heat treated at 60°C in methanol solution of MMA. The experimental results suggest that the prepared PMMA particles were kinetically favored and the localized polymerization of the MMA monomer on PMMA seed particle surface was responsible for the formation of the raspberry‐like particles. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Separation of Small Particles Suspended in Liquid by Nonuniform Traveling Field

A study of size and charge-dependent separation of small particles in liquid using a traveling-field-type electric curtain device is made. The principle of the separation is to make use of the spatial harmonic components of the rotating traveling field produced by such a device, the first harmonic propagating in one direction, which plays a dominant role in the region distant from the electrodes, and the second harmonic propagating in the opposite direction, which becomes dominant near the electrodes. Small particles brought into this field undergo circular motion and, as a result of field nonuniformity, are repelled from the electrodes and drift in the direction of the dominant harmonics. The lighter or more charged particles are strongly repelled from the electrodes and swept by the first harmonic, while the heavier or less charged particles can approach the electrodes and are transported by the second harmonic in the opposite direction, thus enabling separation by mass and charge. First a theoretical investigation of this method is made to clarify the operation conditions for the separation, then the experimental observations of particle motion are made and scaling laws of transport velocity with the applied voltage and frequency are confirmed. Finally, an example of a cell separator design using this method is presented.     

Polymers degradable under environmental conditions through end-modification of poly(α-methylstyrene) derivatives

To induce degradabilities in polymers in response to environmental conditions, the end-modification reactions of poly(α-methylstyrene) derivatives were carried out. When diphenylphosphine chloride was used as a modifier for the living end of para-substituted PMS, the coupling efficiency was ca. 50%. 2-Phenylallyl halide derivatives such as 2-phenylallyl bromide, 2-(4-tolyl)allyl bromide, and α-trifluoromethylstyrene were found to be suitable end-modification agents. For example, ω-2-phenylallyl PMS was prepared with almost quantitative functionality by the reaction of the living PMS with 2-phenylallyl bromide. In a similar way, ω-3,3-difluoro-2-phenylallyl and ω-2-(4-tolyl)allyl PMS derivatives were synthesized. Based on thermogravimetric analysis, onset of the degradation temperature of the end-modified PMS derivatives decreased in the following order: ω-hydrogen- > ω-3,3-difluoro-2-phenylallyl- > ω-2-phenylallyl- > ω-2-(4-tolyl)allyl-PMS. Actually, the onset temperature of ω-2-(4-tolyl)allyl-PMS derivatives was 50°C lower than that of ω-H-PMS derivatives. These results indicate that the active species is produced effectively at the end unsaturated bond, which initiates the depolymerization of the polymer at rather low temperatures. Ionic degradation of these polymers was also investigated using butyllithium as an anionic initiator and methanesulfonic acid as a cationic initiator. Tendencies similar to the thermal degradation were observed. Therefore, it is concluded that a 2-phenylallyl substituent at the end of the PMS chain induces effective degradation through several mechanisms such as radical, anionic and cationic depolymerization reactions.     

Novel Heneicosadienoic and Tricosadienoic Acid Isomers in Ovaries of Marine Archaeogastropods

To investigate unusual odd-chain fatty acids (FA) from gonads of archaeogastropods, limpets Cellana grata and Cellana toreuma, a subfraction enriched in FA with two double bonds extracted from the gonads was obtained by using argentation thin-layer chromatography. The resulting fraction was analyzed by using capillary gas chromatography-mass spectrometry of its methyl esters, 3-pyridylcarbinol esters and pyrrolidide derivatives. Six novel all-cis diene isomers were identified as 7,18-heneicosadienoic (21:2Δ7,18), 8,14-tricosadienoic (23:2Δ8,14), 9,15-tricosadienoic (23:2Δ9,15), 7,18-tricosadienoic (23:2Δ7,18), 9,18-tricosadienoic (23:2Δ9,18), and 9,20-tricosadienoic (23:2Δ9,20) acids. In the present study, the differences in the proportion of tricosadienoic acid isomers between the ovary lipids of C. grata and C. toreuma were recognized.     

Effect of Talc Size on Surface Roughness and Glossiness of Polypropylene Injection Molding Application to Automotive Plastics

Talc-containing polypropylene (PP) resin is extensively employed in automobiles. Herein, considering the microstructure transfer process in injection molding, the effect of the talc's dispersibility and particle size on this process and its impact on the gloss level of the product were investigated. Results show that a fine unevenness of about several micrometers was self-formed by the shrinkage of PP in nontransferred areas due to the blending of talc. Additionally, the amount of self-formed unevenness tended with an increase in the average particle size of talc. Furthermore, due to PP shrinkage and different densities of talc, it was observed that a fine tiger-stripe pattern was self-formed using special molds with modified microstructure. This self-formed fine unevenness changes the gloss level owing to the diffused light reflection effect. This study proposes controlling this change by controlling the average particle size of talc and structure of the mold. POLYM. ENG. SCI., 60:132–139, 2020. © 2019 Society of Plastics Engineers     

Voltammetric study of electrocatalysis for dioxygen reduction by trinuclear rutheniumammine complex confined in a polymer membrane

Electrocatalytic O₂ reduction was studied using a modified electrode coated with a Nafion membrane (Nf) dispersing a trinuclear ruthenium ammine complex ([(NH₃)₅Ru^IIIORu^IV(NH₃)₄ORu^III(NH₃)₅]Cl₆, Ru-red). When measuring cyclic voltammogram under O₂ atmosphere (at 0.5 mV s⁻¹), catalytic currents due to O₂ reduction were found to develop below −0.2 V (vs. Ag/AgCl). Since Ru-red undergoes irreversible decomposition into the mononuclear complexes via the reduced state (Ru^III-Ru^III-Ru^III) (∼−0.1 V), it is suggested that the electrocatalysis originates from the decomposed species (initial active species: Ru^II(NH₃)₅(OH₂) and Ru^II(NH₃)₄(OH₂)₂) rather than from the Ru-red. Although the present electrocatalyst was also applied to H₂O₂ reduction system, the catalytic activity was found to be poor from the voltammetric behavior. It appeared that the kinetics of the electrocatalysis is much faster in the O₂ reduction than in the H₂O₂ one. A selective and direct catalysis for O₂ reduction into H₂O was suggested from a ring-disk voltammogram to take place by an aggregate of the mononuclear ruthenium complexes in the polymer matrix. In addition, it was found that electrocatalytic O₂ reduction involves a slow kinetic process, so that factors affecting the overall kinetics were discussed in terms of the catalysis mechanism.     

Toughening of cycloaliphatic epoxy resins by poly(ethylene phthalate) and related copolyesters

Poly(ethylene phthalate) (PEP) and poly(ethylene phthalate–co‐ethylene terephthalate) were used to improve the brittleness of the cycloaliphatic epoxy resin 3,4‐epoxycyclohexylmethyl 3,4‐epoxycyclohexane carboxylate (Celoxide 2021?), cured with methyl hexahydrophthalic anhydride. The aromatic polyesters used were soluble in the epoxy resin without solvents and effective as modifiers for toughening the cured epoxy resin. For example, the inclusion of 20 wt % PEP (MW, 7400) led to a 130% increase in the fracture toughness (K_IC) of the cured resin with no loss of mechanical and thermal properties. The toughening mechanism is discussed in terms of the morphological and dynamic viscoelastic behaviors of the modified epoxy resin system. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 388–399, 2002; DOI 10.1002/app.10363