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991.
甲烷磺酸的合成研究   总被引:5,自引:2,他引:5  
先用硫氰化钾(KSCN)和硫酸二甲酯(CH3)2SO4合成硫氰酸甲酯(CH3SCN),再由硝酸溶液将其氧化为甲烷磺酸(CH3SO3H),两步的收率分别可达65%和83.2%,并采用了两种不同的分离和纯化产品的方法。  相似文献   
992.
A new diimide–diacid monomer, N,N′‐bis(4‐carboxyphenyl)‐4,4′‐oxydiphthalimide (I), was prepared by azeotropic condensation of 4,4′‐oxydiphthalic anhydride (ODPA) and p‐aminobenzoic acid (p‐ABA) at a 1:2 molar ratio in a polar solvent mixed with toluene. A series of poly(amide–imide)s (PAI, IIIa–m) was synthesized from the diimide–diacid I (or I′, diacid chloride of I) and various aromatic diamines by direct polycondensation (or low temperature polycondensation) using triphenyl phosphite and pyridine as condensing agents. It was found that only IIIk–m having a meta‐structure at two terminals of the diamine could afford good quality, creasable films by solution‐casting; other PAIs III using diamine with para‐linkage at terminals were insoluble and crystalline; though IIIg–i contained the soluble group of the diamine moieties, their solvent‐cast films were brittle. In order to improve their to solubility and film quality, copoly(amide–imide)s (Co‐PAIs) based on I and mixtures of p‐ABA and aromatic diamines were synthesized. When on equimolar of p‐ABA (m = 1) was mixed, most of Co‐PAIs IV had improved solubility and high inherent viscosities in the range 0.9–1.5 dl g?1; however, their films were still brittle. With m = 3, series V was obtained, and all members exhibited high toughness. The solubility, film‐forming ability, crystallinity, and thermal properties of the resultant poly(amide–imide)s were investigated. © 2002 Society of Chemical Industry  相似文献   
993.
杨旭华 《腐植酸》2006,(5):15-17
YZ-84润滑减阻剂是以腐植酸盐为y型原料,用造纸废液为Z型原料,以及其他原料制成。它具有润滑、减阻性能好,清洗能力强,性能稳定,可复配使用,不结垢、不粘管,使用方便,成本低等特点,完全能满足新型小口径金刚石钻机高速钻进、绳索取心的技术要求。  相似文献   
994.
《Polymer》2002,43(16):4341-4348
Thermo- and pH-responsive stimuli hydrogels based on N-isopropylacrylamide (N-iPAAm) and methacrylic acid (MAA) have been synthesized and their swelling behaviour studied as a function of composition, pH and temperature. Copolymers varying in composition have been obtained by copolymerizing these two monomers and interpenetrating polymer networks (IPNs) of P(MAA) and P(N-iPAAm) by the sequential method. Temperature and pH have been changed in the ranges from 25 to 40 °C and from 2 to 9, respectively. The swelling behaviour of the hydrogels depends on the nature of the polymer and the environmental conditions, namely pH and temperature. Copolymer gels under basic conditions exhibit higher degree of swelling than the homopolymer ones. The disruption of the complexes dominates the kinetic swelling of MAA enriched gels under basic conditions. The hydrogen bond formation between carboxyl and amide groups has been made clear through the dynamic swelling behaviour of copolymers under acidic conditions. IPNs reduce their ability to swell in water with increasing P(N-iPAAm) content because of the formation of hydrophobic interpolymer complexes through hydrogen bonding. Lower critical solution temperature occurs only in the enriched N-iPAAm copolymers under acidic conditions when the MAA carboxyl groups are unionized.  相似文献   
995.
Thraustochytrids, marine protists whose dominant genera are Thraustochytrium and Schizochytrium, belong to the kingdom Chromista and are known as an industrial source of DHA. We describe here that thraustochytrid strain KH105, isolated as a DHA producer, also accumulates significant levels of β-carotene and xanthophylls including canthaxanthin and astaxanthin. A4-d cultivation using a medium composed of 10% glucose and less than 0.3% of nitrogen sources in a half-concentration of seawater gave an astaxanthin production up to 6.1 mg/L, and canthaxanthin content reached more than 10 mg/L under conditions where a higher concentration of nitrogen sources (6%) was employed. It might be advantageous in mass production systems for these carotenoids to be extracted readily by simply suspending the cells with organic solvents such as acetone and chloroform. Analyses on the morphological and life history features of the KH105 strain revealed that it belongs to the genus Schizochytrium. This particular species of thraustochytrids is thus considered to be a promising source of xanthophylls as well as DHA for use in the food industry.  相似文献   
996.
范雷  刘兆滨  朱建民 《精细化工》2005,22(Z1):35-37
采用氨基磺酸作为硫酸化剂,由烷基酚聚醚制备烷基酚聚醚硫酸盐,讨论了工艺条件对硫酸化反应过程及产品质量的影响,得出了最佳工艺条件:物料配比n(烷基酚聚醚):n(氨基磺酸)=1:1.06,反应温度120-125 ℃,反应时间3.5 h,催化剂LNP-4用量为投料质量0.8%。  相似文献   
997.
通过采用钛酸四异丙酯(TPT)为催化剂,偏苯三酸酐和2-乙基己醇为原料催化合成增塑剂偏苯三酸三异辛酯(TOTM)的基础上。通过正交试验研究了生成产物中和水洗的最佳条件。  相似文献   
998.
Phenomena called surface explosions have been reported for decomposition reactions on single crystals, and have been identified by the use of desorption methods. In particular, in TPD, they are manifested by extremely narrow peaks (as little as 3 K in width) and a desorption rate which increases with time in isothermal experiments. In this paper we report such observations for acetate species on Rh single crystals, but extend this to show for the first time that such effects are not restricted to single crystal/UHV experiments, but can also be found on a Rh/Al2O3 catalyst under ambient pressure conditions. These reactions can be classified as second order autocatalytic surface processes, where free surface Rh sites are an essential component of the reaction. It is shown that coadsorbed adatoms are also essential for such explosions to be seen and their role is proposed to be that of a template layer acting to order the acetate in self-poisoning configurations.  相似文献   
999.
Chinese melon (Momordica charantia L.), also known as bitter gourd, is a tropical crop, grown throughout Asian countries for use as food and medicinals. In 1993, four cultivars of Chinese melon were grown in Mississippi and the seeds were collected. Oil contents of the seeds ranged from 41 to 45% and the oils contained 63–68% eleostearic acid and 22–27% stearic acid. Industrially important tung oil, a “fast-drying oil” used in paints and varnishes, contains 90% eleostearic and 2–3% stearic acid. The ratio of stearic to eleostearic in Chinese melon seed oil is ten times greater than that in tung oil. The higher ratio should reduce the rate of drying and crosslinking and could be advantageous in the paint industry. The defatted meals contained 52–61% protein and would be a good source of methionine.  相似文献   
1000.
Fu-Lung Chen  E. M. Pearce  T. K. Kwei 《Polymer》1988,29(12):2285-2289
Hydrogen-bonded complexes of poly(acrylic acid) and poly(ethyl oxazoline) (PEOx) were prepared by photopolymerization of acrylic acid in which PEOx was dissolved. The glass transition temperatures (Tg) of the complexes are not only higher than those of the blends but also higher than the Tg value of either component polymer. The complexes dissolve in strong proton-accepting solvents like dimethyl formamide or dimethyl sulphoxide (DMSO), are swollen to various degrees in water and methanol, but are resistant to swelling by dioxane. When the density of hydrogen bond donor groups in the chain is reduced by 50% with the use of a copolymer of acrylic acid and methyl methacrylate, intermolecular association still takes place, although the affinity of complexation is reduced to some extent. When interpenetrating networks (semi-IPNs) are prepared by this method, about half of the PEOx can be extracted by DMSO after 4 days. The incomplete removal is probably a result of topographical constraints against diffusion.  相似文献   
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