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991.
N‐trimellitylimido‐L ‐methionine ( 3 ) was prepared by reaction of trimellitic anhydride ( 1 ) with ‐L ‐methionine ( 2 ) in acetic acid solution at refluxing temperature. This diacid was reacted with thionyl chloride, and N‐trimellitylimido‐L ‐methionine diacid chloride ( 4 ) was obtained in quantitative yield. The resulting diacid chloride was reacted with p‐aminobenzoic acid in dry acetone and bis(p‐aminobenzoic acid)‐N‐trimellitylimido‐L ‐methionine ( 5 ) was obtained as a novel optically active amide–imide diacid monomer in high yield. The direct polycondensation of amide–imide diacid monomer 5 with several aromatic diamines was carried out with tosyl chloride (TsCl)/pyridine (Py)/dimetheylformamide (DMF) system. The resulting thermally stable poly(amide–imide)s (PAIs) were obtained in good yields and inherent viscosities ranging between 0.24 and 0.46 dL g?1 and were characterized with FTIR, 1H NMR, CHN, and TGA techniques. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1248–1254, 2007  相似文献   
992.
侯胜珍  张健  王秀军  朱玥珺 《精细化工》2020,37(12):2585-2592
基于苯硼酸聚合物可以与存在于黄原胶糖环单元结构中的伯、仲醇羟基通过硼酸酯键形成动态共价微交联结构的性质对黄原胶进行改性。以偶氮二异丁基脒二盐酸盐(AIBA)为引发剂,通过水相自由基聚合,制备了不同共聚比的丙烯酰胺(AM)、N-(3-二甲氨基丙基)丙烯酰胺(DMAPAM)和3-丙烯酰胺基苯硼酸(AMBB)的三元共聚物P(AM-co-DMAPAM-co-AMBB)。通过1H NMR、FTIR、元素分析和光散射对聚合物结构及相对分子质量进行了表征,并对其与黄原胶复配体系的增黏性、流变性、抗老化性及抗干扰性进行了评价。结果表明:P(AM-co-DMAPAM-co-AMBB)与黄原胶复配后对黄原胶溶液具有明显的增黏性,其中苯硼酸单体的摩尔比为1.0 mol%的聚合物对黄原胶溶液的增黏幅度达43.8%,在8074 mg/L的矿化水中增黏幅度高达56.4%,且复配体系具有良好的抗老化降解性,对乙二醇和1,3-丙二醇具有较强的抗干扰性。  相似文献   
993.
Kan-Yi Pu  Wei Huang 《Polymer》2006,47(6):1970-1978
A series of novel hybrid organic-inorganic light-emitting materials, polyhedral oligomeric silsesquioxane-tethered poly(fluorenyleneethynylene)s, were successfully synthesized via Sonagashira coupling reaction. The chemical structures of these copolymers were determined by 1H NMR and FT-IR spectra. The morphologies of these copolymers were studied in details using TEM and WAXD. The WAXD data showed that POSS formed aggregation instead of crystallization in the polymer matrix, indicating the significant effect of the backbone constraint on POSS crystallization. Furthermore, it also revealed that the interchain interaction weakened and the interchain distance increased after introducing POSS groups. The TEM data indicated that POSS aggregates were well dispersed in polymer matrix. In accordance with the morphological investigation, the results of UV-vis absorption and photoluminescence emission spectra of these copolymers showed that the tendency toward planar conformation of conjugated backbones reduced to a certain extent due to weakened interchain interaction. Accordingly, these copolymers exhibited the enhanced quantum yields in the solid state. In addition, owing to the thermal and oxygen stability of hybrid POSS, the thermal spectral stability of these polymers was also improved greatly.  相似文献   
994.
应用分子蒸馏技术分离提纯玫瑰精油   总被引:17,自引:0,他引:17  
应用刮膜式分子蒸馏装置对玫瑰精油的提纯进行了研究。考察了进料速率、进料温度、蒸发温度和刮膜器转速等因素对玫瑰精油分离效果的影响。通过试验,初步得到了工艺参数的范围:进料速率为50~70 mL/h,进料温度为53~60℃,蒸发温度Ⅰ为100~108℃,蒸发温度Ⅱ为120~130℃,操作压力1.5 Pa,刮膜器转速150~160r/m in,得到的玫瑰精油产品的纯度在86%以上,分离过程总收率大于60%,并为今后工艺参数优化奠定了基础。  相似文献   
995.
毛细管气相色谱法测定核桃油中的脂肪酸   总被引:11,自引:0,他引:11  
讨论了核桃油中脂肪酸的提取方法和毛细管气相色谱法测定条件,并对5种主要脂肪酸进行定量的测定。  相似文献   
996.
997.
制备出一种柱效高、成本低的复合型色谱柱。并利用醇解法进行了脂肪酸甲酯化,用气相色谱法测定了乌桕脂、棕榈油、可可脂、鱼油及自制类可可脂的脂肪酸组成。  相似文献   
998.
煤炭间接液化技术及其在中国的产业化前景   总被引:10,自引:4,他引:10  
吴春来 《煤炭转化》2003,26(2):17-24,33
介绍了国内外煤炭间接液化技术的研究开发和应用,对在中国建设煤炭间接液化示范厂的技术经济进行了简要分析,指出在我国实现煤炭间接液化工业化生产,必须根据市场需求,因煤因地制宜,把提高经济效益放在首位。  相似文献   
999.
An emulsion-based method was developed as an alternative for the introduction of oil-based samples into a graphite furnace to produce a more rapid, precise, and accurate method of analysis. The combination of emulsion sampling and electrothermal atomization for atomic absorption spectroscopy was developed and then applied to the determination of Ni and manganese in neem oil from Venezuela. The optimal concentration of neem oil in the emulsion was 30 and 4% for Ni and Mn, respectively, based on the metal concentration of the neem oil. The stability of the emulsion as a function of time was evaluated. The use of aqueous calibration solutions and the accuracy attained using this method make it attractive for the analysis of oil samples. The metal recovery was between 97 and 101%. Based on the emulsion method, the neem oil samples had 1.39 and 0.21 mg of Mn and Ni per kg of oil, respectively. The wet digestion method indicated a Mn and Ni concentration in the neem oil sample of 1.42 and 0.24 mg/kg, respectively.  相似文献   
1000.
Oil degradation caused by the number of fryings performed and the effect of oil degradation on the color of fried battered squid rings were studied. Spectrophotometric techniques with absorbance in the UV and visible ranges, and iodine, peroxide, and acid values were used to determine oil degradation. Determination of various CIELAB parameters in order to study the external color of the fried battered squid rings revealed no differences in color due to the number of fryings. A study of the color of the battered squid rings at various frying times and temperatures showed significant differences for both variables. Although there was some degradation in the oil after 20 fryings, appearing as a slight darkening, it did not affect the final color of the fried, battered squid rings.  相似文献   
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