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71.
含氨基,羟基吸附剂对胆红素的吸附 总被引:16,自引:0,他引:16
本文分别合成了含氨基和羟基的高分子吸附剂,并对它们对胆红素的吸附性能进行了研究。实验表明,经3小时的吸附后,含氨基和含羟基的吸附剂对胆红素的吸附率可达80%以上,对其吸附胆红素的性能和机理进行了探讨。 相似文献
72.
乙烯基硅烷-丙烯酸酯乳液共聚动力学研究 总被引:7,自引:0,他引:7
以乙烯基三乙氧基硅烷(VTES)、丙烯酸酯为单体,乙氧基醇磺基琥珀酸二钠(A—102)为乳化剂,合成了有机硅改性丙烯酸酯共聚乳液。研究了乳化剂、引发剂、VTES、反应温度以及功能性单体甲基丙烯酸羟乙酯(HEMA)对乳液共聚反应速率的影响。结果表明:聚合速率随乳化剂浓度、引发剂浓度、HEMA浓度的增大及反应温度的升高而增大,但随VTES浓度增大而逐渐减小。由实验得出恒速阶段聚合反应速率R_p与乳化剂浓度C_E、引发剂浓度C_1及有机硅单体浓度C_(VTES)的关系为R_p∝C_E~(0.35)C_I~(0.48)C_(VTES)~(-0.64),表观活化能E_a为81.1kJ·mol~(-1)。 相似文献
73.
Fang Sun David W. Grainger 《Journal of polymer science. Part A, Polymer chemistry》1993,31(7):1729-1740
Copolymers of 2-hydroxyethyl acrylate and 2-methoxyethyl acrylate with variable compositions were synthesized, fractionated, and characterized by 1H-NMR, IR, GPC, and viscometry. These copolymers were further modified via polymer analog esterification of copolymer hydroxy groups by a series of disulfide-containing carboxylic acids including lipoic acid and (n-pentyldithio) alkyl carboxylic acids (n-C5H11SS(CH2)m? COOH, m = 10, 15, 22) in the presence of 1,3-dicyclohexylcarbodiimide (DCC). Esterification reactions were quantitative for copolymers possessing hydroxy monomer contents ≤ 40% when excess acid and DCC were present for sufficiently long reaction times (2–4 days) at room temperature. Copolymer DSC analysis demonstrates a systematic variation of Tg with copolymer composition in good agreement with ideal mixing theory. These disulfide-bearing copolymers spontaneously yield two-dimensional ultrathin polymer films with side chain-dependent layer thicknesses of 20–45 Å by solution adsorption onto freshly deposited gold surfaces. Such ultrathin polymer films are expected to have diverse applications as bound polymeric surface modification reagents. © 1993 John Wiley & Sons, Inc. 相似文献
74.
A series of vinylidene dichloride (VDC) copolymers with methyl acrylate (MA) ascomonomer (3--12wt%), was prepared by free-radical suspension copolymerization. Thepermeability coefficients of the copolymers to oxygen and carbon dioxide were measured at1.0 MPa and at 30℃, and those to water vapor were measured at 30℃ and 100% relativehumidity All the VDC/MA copolymers studied are semicrystalline. As the MA contentincreases, the permeability coefficients of the copolymers to oxygen, carbon dioxide, andwater vapor are progressively increased, caused by decrease in crystalline fraction andincrease in free volume of VDC/MA copolymers. 相似文献
75.
Pedro Merino Julia RevueltaTomas Tejero Ugo ChiacchioAntonio Rescifina Giovanni Romeo 《Tetrahedron》2003,59(20):3581-3592
In the 1,3-dipolar cycloaddition of glyoxylic nitrones with electron-poor and electron-rich alkenes, the configurational instability of the nitrone leads to parallel models when regio- and stereoselectivities are rationalized. The energetics of the cycloaddition reactions have been investigated through molecular orbital calculations at the B3LYP/6-31-G(d) theory level. By studying different reaction channels and reagent conformations, leading to a total of sixteen transition structures for each dipolarophile, the regio- and stereochemical preferences of the reaction are discussed. 相似文献
76.
自交联型丙烯酸酯共聚物乳液的研究 总被引:7,自引:0,他引:7
以羟甲基丙烯酰胺、丙烯酸作为活性单体,采用种子乳液聚合法制得四元体系自交联型丙烯酸酯共聚物乳液。用透射电镜观察了乳胶粒的微观形态,并对共聚物乳液的流变性,稳定性等进行了测试,考察了羟甲基丙烯酰胺和丙烯酸的含量、聚合方式对共聚物乳液性能的影响。 相似文献
77.
Weizhi Wang 《European Polymer Journal》2003,39(6):1117-1123
UV-curable polydimethylsiloxane epoxy acrylate (PSEA) was synthesized by hydrosilylation of allyl glycidyl ether with hydrogen-containing polydimethylsiloxane to give polydimethylsiloxane-type epoxy resin which modified with acrylic acid. The curing speed and the double bond conversion in the UV cured film were influenced by the purity of PSEA with Fourier transform infrared spectroscopy (FT-IR) measurements. The influences of the synthetic process, such as, the reaction temperature, the concentration of reactants and the catalyst which determined the purity and activity of resins were discussed in detail. The structures of this resin were characterized by 1H-NMR and FT-IR spectra. The molecular weight was checked by gel permeation chromatography, and Mn is 45,000. The properties of the cured film were also investigated by thermogravimetric analyzer, dynamical thermal mechanical analysis, and etc. For example, tensile strength (6.9 Mpa), elongation (20%), hardness (A; 18), water absorption (24 h; 2%), weight loss (40 min, 300 °C; 5%) and etc. 相似文献
78.
有机硅改性丙烯酸酯共聚乳液合成方法及胶膜性能的研究 总被引:59,自引:0,他引:59
用一次投料法、单体乳液滴加法和引发剂滴加法有机硅改性丙烯酸酯共聚乳液,聚合过程、胶粒形态及乳液稳定性的观测结果表明:单体乳液滴加法是合成该类乳液的最佳方法,研究了单体乳液滴加法中有机硅含量与聚合反及胶膜性能的关系,结果表明:有机硅含量在15%以下时,聚合反应可以顺利进行,胶膜性能不仅依赖于聚合时有机硅单体的总量,而且还依赖于有机硅单体中活性硅氧烷所占的比例。 相似文献
79.
80.
The crucial factor of the reaction of 2,6-di-tert-butylphenol with alkali hydroxides is temperature, depending on which two types of potassium or sodium 2,6-di-tert-butylphenoxides are formed. These types exhibit different catalytic activity in the alkylation of 2,6-di-tert-butylphenol with methyl acrylate. More active forms of 2,6-But
2C6H3OK or 2,6-But
2C6H3ONa are synthesized at temperatures higher than 160 °C and are predominantly the monomers, which dimerize on cooling. The
data of 1H NMR, electronic, and IR spectra for the corresponding forms of 2,6-But
2C6H3OK and 2,6-But
2C6H3ONa isolated in the individual state are in agreement with cyclohexadienone structure. In DMSO or DMF, the dimeric forms of
2,6-di-tert-butylphenoxides react with methyl acrylate to form methyl 3-(4-hydroxy-3,5-di-tert-butylphenyl)propionate in 64–92% yield.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2138–2143, December, 2006. 相似文献