共查询到20条相似文献,搜索用时 140 毫秒
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分别阐述了良和非良混合溶剂,及非良与非良混合溶剂的致孔作用。在良/非良混合溶剂存在下通过调节两种溶剂的比例,可控制共聚全的孔径和孔容的大小,只要交联度合适,可是比表面积较大的共聚体,在非良/非良混合溶剂存在下,可通过调节两种溶剂的比较,控制其适当的混合溶度参数,所得共聚体的比表面积也大。 相似文献
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提出致孔剂在交联共聚中的作用是使其共聚物珠体内部发生分离,从而形成微孔。并分别从理论上阐明良溶剂,非良溶剂致孔作用,在良溶剂存在下,DVB含量对共聚体的孔结构影响很大;在非良溶剂存在下,此得共聚体的孔径较大,其比表面积较小。 相似文献
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采用混合致孔剂合成大孔MMA-DVB共聚体,并将其用于处理低度酒。结果显示,共聚体对乙醇水溶液中油酸乙酯的吸附量可达36.4mg/g;经共聚体处理的低度酒精清澈透明,醇香味正,完全保留原酒的风味。 相似文献
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含双键大孔径苯乙烯—二乙烯基苯微球的合成与表征 总被引:1,自引:0,他引:1
含双键大孔径苯乙烯-二乙烯基苯微球的合成与表征袁青阚成友刘伟良孔祥正*(山东大学化学系济南250100)关键词苯乙烯-二乙烯基苯共聚树脂,悬浮聚合,树脂微球,复合致孔剂,孔结构1997-07-03收稿,1998-01-12修回国家教委留学服务中心回国... 相似文献
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三磷丙基异氰酸尿酯—二乙烯苯—醛酸乙烯大孔共聚物的合成及… 总被引:1,自引:1,他引:1
根据文献查得的Q,e值,计算了三烯丙基异氰酸尿酯-二乙烯苯-醋酸乙烯三元共聚体系的竞聚率,预测了它们进行共聚的可能性。以甲苯和汽油为致孔剂,采用悬浮聚合的方法合成了此三元大孔共聚物,并研究了致孔剂用量,关联度等对共聚物孔性能的影响。实验发现,此共聚体系在适当条件下,可以制得很高比表面积的大孔共聚体,比表面积可高达1214m^2/g。对合成的共聚物又进行了醇解反应,得到了含羟基的共聚体。 相似文献
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二乙烯苯与乙烯基吡咯烷酮共聚硅质填料的制备及对蛋白质的分离 总被引:1,自引:0,他引:1
大孔硅胶基质与二乙氧基甲基乙烯基硅烷反应后,再与二乙烯,乙烯基吡咯烷酮共聚,制得新型反相色谱填料。实验结果表明,该填料对蛋白质的分离性能好,柱效高,速度快,惰性好。为生物大分子的高效液相色谱分离提供了一种新型填料。 相似文献
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The reactivity ratios of vinyl acetate(VAc) and divinyl benzene (DVB) were calculated from the Q and e values.The possibility of the copolymerization of these two monomers was predicted and the copolymerization was carried out by suspension polymerization technique in the presence of pore producing agent (toluene and gasoine).The relative ratio of acetoxy group and benzene ring in the copolymer were monitored by IR measurement during the polymerization.The variation of pore properties,such as spectific surface area,porosity and average pore diameter,with polymerization time were determined.The copolymers at various polymerization time were alcoholyzed and thus the variation of the hydroxyl group content with polymerization time was studied. 相似文献
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1.INTRODUCTIONVinylacetate(VAc)isacommonandcheapmonomeLUsuallyitisusedtopreparelinearhomopolymerorcopolymeLHowever,becauseoftheusefulestergrouppresentinVAc,italsoat'tractsthegreatinterestsofsomescientistswhoworkintheareaoffunctionalpolymers.Recently,alotofreporthaveappearedusingVAcasamainmonomertopreparecrosslinkedpolymersII~sl.ThesereportsmainlyfocustheinterestsonthesynthesisandapplicationoftheVAccontainingcrosslinkedpolymers.Noreportshavebeenfoundtostudythekineticsofthesynthesisofc… 相似文献
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The copolymerization kinetics of the ethyl acrylate/styrene/azo-bis-isobutyronitrile/benzene/50°C system was found to deviate from the classical rate equation of copolymerization. The experimental results could not be interpreted by the diffusion theory, the penultimate effect, or the theory of electron donor-acceptor complexes. Our kinetic data were consistently described by the theory of hot radicals, and the 13 parameters characteristic for the copolymerization system were determined from an adequate number of data at different compositions by a nonlinear least-squares method. 相似文献
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The copolymerization of polymethyl methacrylate (PMMA) macromer with butyl acrylate in benzene was studied. the PMMA macromer was obtained by radical polymerization in the presence of thioglycollic acid as a chain transfer agent, followed by termination with glycidyl methacrylate. the copolymerization rate and effects of various copolymerization conditions, such as molecular weight of macromer, charging ratio of macromer to monomer, amount of initiator, kind of solvent, concentration, and copolymerization temperature, on grafting efficiency and molecular weight of copolymer were investigated. the copolymers were purified by fractional precipitation. the purified copolymers with uniform PMMA grafts were characterized by GPC, IR, UV, and DSC. Structural parameters of the copolymers were determined by VPO and membrane osmometry. Average grafting number per chain decreases with an increase of conversion. Measurement of mechanical properties of the copolymers shows that both molecular weight and the content of the macromer affect mechanical properties of the copolymer, and within a certain range they behave like a thermoplastic elastomer. 相似文献
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Xia Y Dosseh G Morineau D Alba-Simionesco C 《The journal of physical chemistry. B》2006,110(39):19735-19744
We used differential scanning calorimetry, neutron scattering, and proton NMR to investigate the phase behavior, the structure, and the dynamics of benzene confined in a series of cylindrical mesoporous materials MCM-41 and SBA-15 with pore diameters, d, between 2.4 and 14 nm. With this multitechnique approach, it was possible to determine the structure and, for the first time to our knowledge, the density of confined benzene as a function of temperature and pore size. Under standard cooling rates, benzene partially crystallizes in SBA-15 matrixes (4.7 相似文献
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壳多糖与丙烯酸丁酯的乳液接枝共聚研究 总被引:10,自引:0,他引:10
以十二烷基苯磺酸钠为乳化剂,过硫酸钾-亚硫酸氢钠为引发剂,研究了壳多糖与丙烯酸丁醋的乳液共聚合,结果表明当[K2S2O8]=[NaHSO3]=2.57×10-3mol·1-1,[BA]=0.68mol.1-1,[Chitosan]=19.2g·l-1,在70℃下反应5小时,共聚反应的接技率和接枝效率均较高.用红外光谱,差热分析,X射线衍射,扫描电镜对接技共聚物进行了表征,此外测试了共聚物胶乳成膜的机械性能,表明用丙烯酸丁酯对壳多糖进行接枝改性,可提高壳多糖的韧性,扩大其应用范围. 相似文献
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S. Poowiski 《Journal of polymer science. Part A, Polymer chemistry》1984,22(11):2887-2894
A mechanism of matrix copolymerization in which a monomer (or macroradical) is complexed by matrix was considered. For this case a composition equation was formulated. It was shown that in general case reactivity ratios are dependent on the matrix concentration. The influence of the critical length of a complexed radical on the process of copolymerization is also discussed. A series of copolymerizations of methacrylic acid and styrene were carried out using various compositions of initial monomer mixtures. The process was performed in benzene in the presence of poly(ethylene glycol) as a matrix. The copolymerization were carried out at various ratios of the monomer being complexed (methacrylic acid) to the matrix. Compositions of the complexes prepared were determined by the NMR method. Reactivity coefficients for both monomers were found and the results are discussed on the basis of the derived equation. 相似文献