Gas chromatographic separation of wax esters based on the degree of unsaturation

The wax esters of sperm whale head oil have been characterized by gas-liquid chromatography on an APOLAR 10C column according to their carbon number and number of double bonds. The novel technique permits the direct quantitative analysis of saturated and unsaturated wax esters.     

Study on modified phenolic resin. I. Modification with homopolymer prepared from p-hydroxyphenylmaleimide

We studied the improvement of heat resistance and mechanical properties of phenolic resin modified with polymers prepared from p-hydroxyphenylmaleimide (HPMI). Homopolymers of HPMI and copolymers of HPMI with some vinyl monomers were synthesized and M_n T_g and thermal decomposition temperature of them were measured by GPC, DSC, and TG, respectively. The miscibility of homopolymer with novolac was examined by DSC. It was found that the homopolymer had good heat resistance and good miscibility with novolac. Molding compounds were prepared by hot roll-kneading the mixtures of novolac, the homopolymer, hexamethylenetetramine, and glass fiber. It was found that molded test pieces had good heat resistance.     

高速气流冲击式粉体表面改性装置——HYBRIDIZATION系统及应用

利用高速气流冲击法进行粉体/粉体系表面改性技术,是迄今为止各种粉体材料开发中最为引人注目的技术之一。HYBRIDIZATION(下称HYB)系统是利用高速气流冲击法对微粉体进行干式/机械化处理,是使材料复合化的最实用的装置,可对各类有机物、无机物、金属等进行广泛组合,通用性很强,适用于许多行业领域。从本文所述的系统构成、型式,有关的典型球形化处理的运转特性,利用复合化高温粉体测定被处理粉体表面温度,利用颜料改变色调等的处理特点及该系统的适用性等(一部分是从已发表的学术论文及专利上摘录的),可以说明HYB系统的概况。     

PTCR Characteristics in Barium Titanate Ceramics with Curie Points Between 60° and 360°C

PTCR characteristics in porous semiconducting barium titanate ceramics with Curie points from 60° to 360°C were investigated. The magnitude of the PTCR effect in these cerumics decreases self-onsistently with increasing Curie point within this temperature range. A PTCR efSect of more than 4 orders of magnitude was ahserved, for a Ba_0.44Pb_0.6TiO₃ ceramic with a Curie point of 360°C .     

Digestion of crosslinked poly(vinylpyridinium halide) by activated sludge,and application to make poly(methyl methacrylate) biodegradable by incorporation of a pyridinium group into the main chain

Crosslinked poly(N-benzyl-4-vinyipyridinium bromide) has been found to be digested by activated sludge obtained from sewage works. As an extension of this work, the authors attempted to make poly(methyl methacrylate) biodegradable by incorporation of a pyridinium group. Poly(methyl methacrylate) containing a small amount of N-benzyl-4-vinylpyridinium chloride in the main chain showed remarkable reduction in molecular weight and gravimetric weight when placed in an aeration tank of a sewage works. Molecular weight reduction by activated sludge was more conspicuous when content of the pyridinium group was larger and the original molecular weight before the biological treatment was lower. Since insoluble pyridinium-type polymer captures microbial cells alive, this biodegradation appears to be facilitated by enhancement of affinity of the synthetic hydrophobic polymer with cells of microogranisms. © 1994 John Wiley & Sons, Inc.     

Functional metal-porphyrazine derivatives and their polymers, 10. Secondary fuel cells based on oxygen reduction on platinum electrode modified by polymers and metal-phthalocyanines

Secondary fuel cells based on oxygen reduction of platinum electrode modified by polymers and metal-phthalocyanine (Mt = Fe(III), Co(II), Ni(II), and Cu(II)) were studied. The discharge curves for the platinum electrode modified by poly(2-vinylpyridine) (or polystyrene) and Co-phthalocyanine in 30% KOH aqueous solution, for a 30 min charge at 500 μA, followed by a 100 μA discharge showed a stable plateau at about ?0.24 V SCE (Saturated Calomel Electrode). The open circuit voltage (vs. Zn) of the cell was 1.2 V, and the discharge capacity was of 46 A · h/kg. For this battery there was no significant decay in its characteristics after more than 30 charge-discharge cycles. In Mt-phthalocyanines, the values decreased in the order of Co(II) > Fe(III) > > Cu(II) > Ni(II). From a cyclic voltammogram for the electrode modified by the polymer and Co-Pc, the cathodic reactions were discussed.     

Functional monomers and polymers, 64. Synthesis of poly-β-alanine from β-alanine, β-alanyl-β-alanine,and β-alanyl-β-alanyl-β-alanine 4-dodecanoyl-2-nitrophenyl esters

Active 4-dodecanoyl-2-nitrophenyl esters of β-alanine, β-alanyl-β-alanine, and β-alanyl-β-alanyl-β-alanine were prepared, and tried to polymerize in various solvents. Nonpolar solvents were found to be convenient for the polycondensation reaction. The yield of the polycondensation was high for the monopeptide ester, and less for the dipeptide and tripeptide esters. The effect of temperature on the polycondensation reaction was also studied.     

Effect of oxidized oil on lipogenic enzymes

Male Wistar rats were fed for 4 wk on diets containing 2% oxidized corn oil. Liver tissue was then studied to determine the effect of feeding peroxidized oil on lipogenic enzymes. Although substances which reacted with thiobarbituric acid increased in liver microsomes and mitochondria with increasing peroxide values of the dietary corn oil fed, the activities of glucose-6-phosphate dehydrogenase, malic enzyme and acetyl-CoA carboxylase in liver were unchanged. However, when rats were fed for 2 wk on diets containing 10% fat, of which 0.5, 5 or 10% was unoxidized corn oil and the remainder was hydrogenated beef tallow filler, the lipogenic enzyme activities and also the liver triglyceride levels were observed to decrease with increasing amounts of dietary corn oil. Therefore, although a synthetic diet containing corn oil was easy to oxidize spontaneously, the reductions of lipogenic enzymes in rats fed the diet would not have been caused by lipid peroxides but by unsaturated fatty acids themselves.     

Sintering of Ceria-Doped Tetragonal Zirconia Crystallized in Organic Solvents, Water, and Air

Amorphous CeO₂–ZrO₂ gels were prepared by coprecipitation in ammonia solutions. The onset of crystallization of the gels, from calcining in air, was 420°C, while 200° to 250°C in the presence of water and organic solvents such as methanol and ethanol. The sintering behaviors of CeO₂–ZrO₂ powders were sensitive to the crystallizing conditions, since hard agglomerates formed when the precipitated gels were crystallized by normal calcination in air, whereas soft agglomerates formed when they were crystallized in water or organic solvents. CeO₂–ZrO₂ powders crystallized in methanol and water at 250°C were sintered to full theoretical density at 1150° and 1400°C, respectively, whereas that crystallized by calcination in air at 450°C was sintered to only 95.2% of theoretical density, even at 1500°C.     

Preparation of poly(p-phenylene terephthalamide)/poly(vinyl chloride) molecular composite and its thermal and mechanical properties

Poly(p-phenylene terephthalamide) (PPTA) was blended with poly(vinyl chloride) (PVC) by solution-blending method. PPTA was metalated for dissolving in dimethyl sulfoxide. Dimethyl sulfoxide was used as a common solvent. In PPTA/PVC composite, PPTA accelerated the thermal degradation of PVC. PPTA molecules are aggregated as microfibrillar form in PVC matrix. Such microfibrils are dispersed homogeneously in PVC matrix, according to polarizing microscopic observation. The average diameter of the microfibrils becomes smaller in the composite with lower content of PPTA. In the surface region of PPTA microfibrils the intermolecular hydrogen bonds between C? Cl of PVC and N? H of PPTA are formed. Young's modulus and the yield stress at room temperature were higher in the composites than those in PVC. The modulus of the composites was higher, especially at the high temperatures above their glass transition temperatures, than that in PVC. The temperature dependence of modulus can be calculated by using the mechanical model equivalent to the quasi-3-dimensional microfibrillar model which will be approximately applied to the composite structure. It becomes apparent that the modulus of the PPTA microfibrils evaluated by using the mechanical model is higher in the higher molecular weight PPTA.