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Poly(methyl acrylate)-b-poly(5,6-benzo-2-methylene-1, 3-dioxepane) (PMA-b-PBMDO) was synthesized by two-step atom transfer radical polymerization (ATRP). Firstly, ATRP of methyl acrylate (MA) was realized using ethyl α-bromobutyrate (EBrB) as initiator in the presence of CuBr/2,2'-bipyridine. After isolation, poly(methyl acrylate) withterminal bromine (PMA-Br) was synthesized. Secondly, the resulting PMA-Br was used as a macromolecular initiator in theATRP of BMDO. The Structure of block copolymer was characterized by ~1H-NMR spectroscopy. Molecular weight andmolecular weight distribution were determined on a gel permeation chromatograph (GPC). 相似文献
84.
青霉素酰化酶在甲基丙烯酸缩水甘油酯共聚物上的固定化 总被引:6,自引:0,他引:6
用共价键合法将青霉素酰化酶固定化在珠状多孔的甲基丙烯酸缩水甘油酯(GM)共聚物上,研究了固定化反应时间、温度、pH值和酶液用量对固定化青霉素酰化酶的表观活性、表观偶联效率、活性回收及稳定性的影响.将GM共聚物载体加入到磷酸缓冲液(0.1mol/L,pH10.8)与青霉素酰化酶液(每克干载体用酶液1ml)的混合溶液中,在30℃下反应72h,单位质量(干重)固定化酶的表观活性为348U/g,表观偶联效率为66.7%,活性回收为31.7%. 相似文献
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Ting Wang Yan-Qiang Wang Yan-Lei Su Zhong-Yi Jiang 《Journal of membrane science》2006,280(1-2):343-350
A new random copolymer was synthesized by reacting hydrophilic N,N-dimethyl-N-methacryloxyethyl-N-(3-sulfopropyl) (DMMSA) with hydrophobic butyl methacrylate (BMA) through a conventional radical polymerization. The as-prepared sulfobetaine copolymer (DMMSA–BMA) was blended with polyethersulfone (PES) to fabricate antifouling ultrafiltration membrane for BSA separation. The X-ray photoelectron spectroscopy analysis of blend membranes revealed concentration of sulfobetaine groups at the membrane surfaces that endowed the membrane with higher hydrophilicity and better antifouling property. For the membrane with 8.0 wt% DMMSA–BMA copolymer concentration (No. 5), irreversible fouling has been considerably reduced and the flux recovery rate of the blend membrane reached as high as 82.8%. Furthermore, the blend membrane could effectively resist BSA fouling in a wide pH range from 4.0 to 8.0. 相似文献
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Polyazoamide(PAA) was used as initiator to prepare block copolymer P(MMA-b-St) byfree radical polymerization. The fraction of block copolymer was about 50%. The structureof the block-copolymer was characterized by IR and the results of ~1H-NMR and GPCshowed that the content of the block and the molecular weight (M_w) of the prepolymerand block copolymer could be controlled by varying the mol ratio of styrene/PAA andMMA/prepolymer. DSC and TEM results revealed that the block copolymer has twoseparated glass transition temperatures and phase separation within the domain structure. 相似文献
90.
A. B. Nastasovi A. E. Onjia S. K. Milonji S. M. Jovanovi 《Journal of Polymer Science.Polymer Physics》2005,43(18):2524-2533
Macroporous crosslinked poly(glycidyl methacrylate‐co‐ethylene glycol dimethacrylate) (PGME) was synthesized by suspension copolymerization and modified by ring‐opening reaction of the pendant epoxy groups with ethylene diamine (EDA). Inverse gas chromatography (IGC) at infinite dilution was applied to determine the thermodynamic interactions of PGME and modified copolymer, PGME‐en. The specific surface areas of the initial and modified copolymer samples were determined by the BET method, from low‐temperature nitrogen adsorption isotherms. The specific retention volumes, V, of 10 organic compounds of different chemical nature and polarity (nonpolar, donor, or acceptor) were determined in the temperature range 333–413 K. The weight fraction activity coefficients of test sorbates, , and Flory–Huggins interaction parameters, , were calculated and discussed in terms of interactions of sorbates with PGME and PGME‐en. Also, the partial molar free energy, , partial molar heat of mixing, , sorption molar free energy, ΔG, sorption enthalpy ΔH, and sorption entropy, ΔS, were calculated. Glass transitions in PGME and PGME‐en, determined from IGC data, were observed in the temperature range 373–393 K and 363–373 K, respectively. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2524–2533, 2005 相似文献