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991.
腐蚀金属电极的电化学频域测量研究进展──金属腐蚀与防护研究所电化学研究介绍之一 总被引:1,自引:0,他引:1
腐蚀金属电极的电化学频域测量研究进展──金属腐蚀与防护研究所电化学研究介绍之一曹楚南(金属腐蚀与防护国家重点实验室,金属腐蚀与防护研究所,沈阳110015)腐蚀电化学是研究与腐蚀有关的电化学问题,具体的研究对象为腐蚀金属电极。虽然电化学中的基本原理和... 相似文献
992.
L. A. Chekulaeva I. A. Garbuzova V. V. Gavrilenko L. B. Danilevskaya V. A. Kotel'nikov 《Russian Chemical Bulletin》1996,45(9):2199-2202
Alkali metal salts of acrylamide C3H4NOM (M = Li, Na, and K) were synthesized for the first time by metallation of acrylamide with alkali metals, their alkyl derivatives, or hydrides. The structures of the compounds synthesized were studied by Raman and IR spectroscopy. Based on the results obtained, an ionic structure was proposed for the salts. The salts were tested as initiators of the anionic polymerization of acrylamide. The catalytic activity of C3H4NOM in the polymerization of acrylamide is not lower than that of the well known catalyst, KOBu1.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 2316–2319, September, 1996. 相似文献
993.
A. A. Murav'ev S. V. Pribysh Yu. P. Baidarovtsev V. S. Savost'yanov A. N. Ponomarev 《Russian Chemical Bulletin》1994,43(5):809-811
The electrophysical characteristics of metallopolymers obtained by spontaneous polymerization of complexes of Er, Ca, and UO2 nitrates with acrylamide were investigated. The conductivity () at direct current was measured (10–5 to 10–6 Ohm–1 cm–1), and its alterations during the polymerization were observed. The conductivity of the metallopolymers obtained depends essentially on the voltage applied during the polymerization and the component ratio in the original mixture. It is concluded that the conductivity is ionic in character. The conductivity and the electret properties discovered depend on the moisture content of the samples.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 865–867, May, 1994. 相似文献
994.
Hong Wang Jian Hua Dong Kun Yuan Qiu 《Journal of polymer science. Part A, Polymer chemistry》1998,36(5):695-702
ABA-type block copolymers of poly(trimethylene carbonate) with poly(ethylene glycol) (Mn 6820), PTMC-b-PEG-b-PTMC, were synthesized by the ring-opening polymerization of 1,3-dioxan-2-one (trimethylene carbonate) in the presence of poly-(ethylene glycol) with stannous octoate catalyst, and the copolymers with various compositions were obtained. The PTMC-b-PEG-b-PTMC copolymers were characterized with Fourier transform infrared and nuclear magnetic resonance spectroscopies. The intrinsic viscosities of resulting copolymers increased with the increase of 1,3-dioxan-2-one content in feed while the molar ratio of monomer over catalyst kept constant. It has been observed that the glass transition temperature (Tg) of the PTMC segments in copolymers, recorded from differential scanning calorimetry, was dependent on the composition of copolymers. The melting temperature (Tm) of PEG blocks in copolymer was lower than that of PEG polymer, and then disappeared as the length of PTMC blocks increased. The results of dynamic contact angle measurement clearly revealed that the hydrophilicity of resulting copolymers increased greatly with the increase of PEG content in copolymers. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 695–702, 1998 相似文献
995.
996.
Eri Yoshida Atsutoshi Sugita 《Journal of polymer science. Part A, Polymer chemistry》1998,36(12):2059-2068
Synthesis of poly(styrene-b-tetrahydrofuran (THF)-b-styrene) triblock copolymers was performed by transformation from living cationic into living radical polymerization, using 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (4-hydroxy-TEMPO) as a transforming agent. Sodium 4-oxy-TEMPO, derived from 4-hydroxy-TEMPO, reacted with the living poly(THF), which was prepared by cationic polymerization of THF using trifluoromethanesulfonic acid anhydride as an initiator, resulting in quantitative formation of the poly(THF) with TEMPO at both the chain ends. The resulting polymers were able to serve as a polymeric counter radical for the radical polymerization of styrene by benzoyl peroxide, to give the corresponding triblock copolymer in quantitative efficiency. The polymerization was found to proceed in accordance with a living mechanism, because the conversion of styrene linearly increased over time, and the molar ratio of styrene to THF units in the copolymer also increased as a result of increasing the conversion. The TEM pictures demonstrated that the resulting copolymers promoted microphase segregation. It was found that the films of these copolymers showed contact angles intermediate between those of poly(THF) and of polystyrene. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 2059–2068, 1998 相似文献
997.
998.
Radio frequency plasma polymerization of vinylidene fluoride was used to modify the surface properties of nitrile rubber. The chemistry and frictional properties of the plasma films were characterized. FTIR transmission spectra and EDX analysis of plasma polymer films deposited on NaCl windows showed that the degree of fluorination of the plasma polymers increased as plasma power was increased from 25 to 50 W, and then decreased monotonically at higher powers. An estimation of the actual F/C ratio from EDX data indicated that the plasma polymer films contained approximately one fluorine atom for every 2–5 carbon atoms. Sliding friction tests on a Delrin countersurface showed that the coefficient of friction of the plasma treated rubbers was lower than untreated rubber, but slighly higher than rubber coated with silicone oil. Repetitive sliding friction testing showed that silicone oil treated samples had a longer lubricating lifetime than plasma treated samples. However, cyclic friction tests conducted with nitrile rubber o-rings yielded similar frictional behavior and lubricating lifetimes for silicone oil and plasma treatments. There was no correlation between chemical composition and the frictional and wear properties of the plasma films. Environmental scanning electron micrographs showed that the plasma films were brittle and tended to crack and flake off during wear testing. 相似文献
999.
SIS-PAn导电橡胶复合物的制备和性能 总被引:5,自引:0,他引:5
用原位聚合方法在SIS(苯乙烯-异戊二烯-苯乙烯嵌段共聚物)橡胶基体中合成聚苯胺(PAn),可形成均匀复合的SIS-PAn导电橡胶膜.成膜后紧朝玻璃的膜面导电,而朝向空气的膜面却绝缘.膜中PAn的含量只有5.8%(质量分数)或An/SIS的投料比为0.2时,导电复合物膜的表面电阻和导电率即可分别达到300Ω/□和0.07S·cm~(-1)分析了制备条件,包括PAn含量、酸量、氧化剂用量、表面活性剂用量、交联剂用量和模具材料等因素对SIS-PAn复合物导电性能的影响. 相似文献
1000.
一种液晶共聚酯/粘土纳米复合材料的制备及其相转变温度 总被引:5,自引:0,他引:5
一些无机微粒被广泛用做聚合物的增强材料,其中特别引起人们注意的是一种粘土,即蒙脱土(montmorillonite).蒙脱土具有层状结构,其特点一是微粒尺寸小,二是可以和多种单体发生插层聚合反应,给出聚合物/蒙脱土纳米复合材料[1~3].纳米复合材料指的是其基质中分散相的尺寸至少有一维小于100nm数量级的复合材料.由于其纳米尺度效应、大的比表面积以及强的界面相互作用,纳米复合材料的物理力学性能优于相同组分常规复合材料.因此,无论从基本理论研究角度还是从应用角度上看,对聚合物纳米复合材料的研究都… 相似文献