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991.
Sung‐Jun Cho 《应用聚合物科学杂志》2003,88(8):1904-1910
The polymerization of ?‐caprolactam between the interlamellar spaces of the [TEACOOH]–montmorillonite intercalations complex was attempted using Na–montmorillonite and 10‐carboxy‐n‐decyltriethylammonium bromide to achieve [TEACOOH]–polycaprolactam–montmorillonite, in which montmorillonite (inorganic polymer) is chemically bonded with the polycaprolactam (organic polymer). The results of X‐ray and IR analysis for the samples obtained after polymerization showed that the polymerization reaction has been successfully accomplished. For the purpose of studying the polymeric reaction product more precisely, we have isolated the polymerized product from the silicate layers and analyzed it with X‐ray diffractometer and IR spectrometer. Comparison of the results of X‐ray and IR analysis between the isolated polymer and the polymer that was synthesized by the reaction of ?‐caprolactam only with the organic cation without montmorillonite showed that both obtained polymers are the same compounds. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1904–1910, 2003 相似文献
992.
AC/MMA接枝改性天然胶乳的制备及性能研究 总被引:1,自引:1,他引:1
以丙烯基氯(AC)和甲基丙烯酸甲酯(MMA)接技改性天然胶乳,采用正交试验方法研究引发剂用量,反应温度,单体配比,胶乳浓度等对接枝聚合反应中单体转化率和接枝率的影响,测试了改性天然胶乳的粘度,粘接性能及其硫化胶膜的力学性能,耐溶剂性和阻燃性,结果表明,适宜的接枝聚合反应条件为:引发剂异丙苯过氧化氢(CHP)和四乙烯五胺(TEP)的质量分数分别为0.58%和0.36%-0.72%(占橡胶质量的百分率)、反应温度为30℃、单体体积配比v(MMA):v(AC)=1.5:1、胶乳质量分数为53.3%,所得接枝胶乳粘度较高,粘结性能较好,耐溶剂性能剂,且有较好阻燃性。 相似文献
993.
Pt/Al2O3 catalysts with platinum contents of 0.1, 1.0 and 3.0 wt% were used for the low temperature combustion of methanol in the absence and the respective presence of a trace amount of ammonia. It is observed that ammonia inhibits the combustion of methanol, which is due to competition between methanol and ammonia for the same sites. For a fixed space velocity and without ammonia in the gas, the performances of the catalysts increase up to a Pt loading of 1.0 wt%. In the presence of ammonia, however, no upper limit of performance is observed with increased Pt content. The results are discussed in terms of both Pt–support interface and the Pt surface being active. 相似文献
994.
995.
3-甲基-2-丁烯-1-醇的合成方法 总被引:4,自引:0,他引:4
二氯菊酯是拟除虫菊酯杀虫剂的重要中间体。依据不同原料,介绍了其前驱体3-甲基-2-丁烯-1-醇三种合成方法,阐述了不同的合成方法得到的不同结果,比较了各种方法的可行性。重点介绍了以异丁烯应用普林斯反应的合成方法,其原料价廉易得,反应两步完成,副产物少,是主要的工业化生产方法。 相似文献
996.
设计并合成了3个2-对溴苯基-5-芳基-1,3,4-噁二唑类化合物,它们是进一步合成具有光电功能特性的噁二唑类化合物的重要前体。探讨了不同的合成条件和途径,发现以P(Ph)3/(Et)3N/CCl4作为脱水剂来合成非对称的1,3,4-噁二唑是较好的合成方法。 相似文献
997.
以甲基二氯硅烷和甲醇为原料,采用气-液相反应法合成出甲基二甲氧基硅烷;然后,将甲基二甲氧基硅烷与3,3,3-三氟丙烯在铂催化剂作用下进行硅氢加成反应,得到3,3,3-三氟丙基甲基二甲氧基硅烷。考察了原料配比、填料种类等因素对醇解反应的影响以及铂催化剂的种类、用量、反应温度等对加成反应的影响。结果表明,最优合成条件为:在醇解反应中,甲基二氯硅烷与甲醇的量之比为1∶1·8、醇解温度50℃、甲醇滴加速度2mL/min、N2流量80mL/min,在此条件下,甲基二甲氧基硅烷的收率为86%;在加成反应中,采用自制的铂催化剂,当铂催化剂与甲基二甲氧基硅烷的量之比为3·0×10-4∶1、反应温度为120℃时,3,3,3-三氟丙基甲基二甲氧基硅烷的收率达90%。此法可有效提高3,3,3-三氟丙基甲基二甲氧基硅烷的收率。 相似文献
998.
Spherical lithium manganese oxide spinel was synthesized by an ultrasonic spray pyrolysis method, and has been characterized using X-ray diffraction, scanning electron microscopy, transimission electron microscopy and electrochemical cycling at 3 V regions. The LiMn2O4 powders were composed of about 10 nm-sized primary particles. The delivered discharge capacity of the synthesized nano-material was 125 mAh g−1 between 2.4 and 3.5 V and its retention was about 96% upon 50 cycling. From the high resolution transmission electron microscopic study, it was found that structural transition of the parent material did not occur even after the 50th electrochemical cycling on the 3 V region. It seems that the reversible structural change is possible for nanocrystalline LiMn2O4 as observed by the X-ray diffraction and transition electron microscopic observations. 相似文献
999.
LiNi1/3Co1/3Mn1/3O2 cathode materials have been coated with Al2O3 nano-particles using sol-gel processing to improve its electrochemical properties. The X-ray diffraction (XRD) pattern of the as-prepared Al2O3 nano-particles was indexed to the cubic structure of the γ-Al2O3 phase and had an average size of ∼4 nm. The XRD showed that the structure of LiNi1/3Co1/3Mn1/3O2 was not affected by the Al2O3 coating. However, the Al2O3 coatings on LiNi1/3Co1/3Mn1/3O2 improved the cyclic life performance and rate capability without decreasing its initial discharge capacity. These electrochemical properties were also compared with those of LiAlO2-coated LiNi1/3Co1/3Mn1/3O2 cathode material. The electrochemical impedance spectroscopy (EIS) was studied to understand the enhanced electrochemical properties of the Al2O3-coated LiNi1/3Co1/3Mn1/3O2 compared to uncoated LiNi1/3Co1/3Mn1/3O2. 相似文献
1000.
Takashi Hayakawa Hideo Orita Masao Shimizu Katsuomi Takehira Arnfinn G. Andersen Kiyoshi Nomura Yusuke Ujihira 《Catalysis Letters》1992,16(4):359-371
The catalytic activity of LaCoO3–-based mixed oxides for the oxidative coupling of methane has been tested by TPR and cyclic reaction. Characterization has been done by XRD, TGA and Mössbauer spectrometry. It is likely that the perovskite-crystal structure containing hypervalent metal ions has an important role and that unique structural oxygen species in the perovskite contribute to the partial oxidation of methane. 相似文献