共查询到20条相似文献,搜索用时 0 毫秒
1.
Cellulose functionalization via high-energy irradiation-initiated grafting of glycidyl methacrylate and cyclodextrin immobilization 总被引:2,自引:0,他引:2
Gilles Desmet Erzsébet Takács László Wojnárovits Judit Borsa 《Radiation Physics and Chemistry》2011,80(12):1358-1362
Cotton-cellulose was functionalized using gamma-irradiation-induced grafting of glycidyl methacrylate (GMA) to obtain a hydrophobic cellulose derivative with epoxy groups suitable for further chemical modification. Two grafting techniques were applied. In pre-irradiation grafting (PIG) cellulose was irradiated in air and then immersed in a GMA monomer solution, whereas in simultaneous grafting (SG) cellulose was irradiated in an inert atmosphere in the presence of the monomer. PIG led to a more homogeneous fiber surface, while SG resulted in higher grafting yield but showed clear indications of some GMA-homopolymerization. Effects of the reaction parameters (grafting method, absorbed dose, monomer concentration, solvent composition) were evaluated by SEM, gravimetry (grafting yield) and FTIR spectroscopy. Water uptake of the cellulose decreased while adsorption of a pesticide molecule increased upon grafting. The adsorption was further enhanced by β-cyclodextrin immobilization during SG. This method can be applied to produce adsorbents from cellulose based agricultural wastes. 相似文献
2.
Kse Kazm Mavlan Miran Nuruddin Md Gmez Ana Mara Ulloa Youngblood Jeffrey P. 《Cellulose (London, England)》2022,29(3):1623-1636
Cellulose - Cellulose nanocrystal (CNC) modified poly(2-hydroxy ethyl methacrylate- glycidyl methacrylate) [poly(HEMA-GMA)] cryogels were prepared by base-catalyzed CNC addition. Resultant cryogels... 相似文献
3.
Graft polymerization of glycidyl methacrylate (GMA) onto polyethylene fiber was carried out in emulsion solution obtained by dissolving GMA in water with sodium n-dodecyl sulfate (SDS) as a surfactant. GMA micelles diameter was 415 nm at 5% GMA with 4% SDS and increased up to 1840 nm at 10% GMA with 12% SDS. Degree of grafting (Dg) which was estimated by the weight gain after grafting increased with the increment of GMA concentration in the range 2 to 8% and slightly reduced at 10% GMA. The increment in SDS concentration from 4% to 16% at 5% GMA reduced Dg from 120% to 18%. In emulsion graft polymerization, Dg was affected by covered area by GMA/SDS micelles on the fiber. 相似文献
4.
The free radical grafting reactivity of glycidyl methacrylate (GMA) onto polypropylene (PP) in the molten state is low. This article shows that adding styrene as a second monomer (or comonomer) increases both the rate and yield of GMA grafting and reduces PP chain scission. The proposed mechanism is that when St is added to the PP/GMA/peroxide grafting system, St reacts first with PP macroradicals to form stable styryl macroradicals. These latter then react (or copolymerize) with GMA to form GMA grafted PP. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1053–1063, 1998 相似文献
5.
The melt free radical grafting of glycidyl methacrylate (GMA) onto high‐density polyethylene (HDPE) was carried out in Brabender internal mixer. The GMA content of the grafted HDPE (HDPE‐g‐GMA) was determined through FTIR by means of a calibration curve. The influence of reaction procedure, radical initiator concentration and addition of a co‐monomer (styrene) on the grafting efficiency was examined. Blends of poly(ethylene terephthalate) (PET) with HDPE and HDPE‐g‐GMA (75/25 w/w) were prepared by melt mixing in internal mixer. The morphology of the blends was then analysed by SEM microscopy. PET/HDPE‐g‐GMA blends displayed improved phase dispersion and interfacial adhesion as compared to unfanctionalized PET/HDPE blend. 相似文献
6.
Ying Luo Min Zhi Rong Ming Qiu Zhang Klaus Friedrich 《Journal of polymer science. Part A, Polymer chemistry》2004,42(15):3842-3852
To improve the tribological performance of nano‐SiC particles filled epoxy composites, surface modification of the fillers is necessary. By means of soapless emulsion polymerization method, graft polymerization of glycidyl methacrylate (GMA) onto the surface of alkyl nano‐SiC was carried out, resulting in composite particles with SiC core and polymeric shell in which polyglycidyl methacrylate (PGMA) is chemically attached to the nanoparticles by the double bonds introduced during the pretreatment with a coupling agent. By analyzing the reaction mechanism, the emulsion polymerization loci were found to be situated at the SiC surface. Also, the factors affecting the grafting yielding of PGMA on the particles were investigated, including monomer concentration, initiator consumption, reaction temperature, reaction time, etc. Accordingly, an optimum grafting reaction condition was determined. It was shown that the grafted nanoparticles exhibit greatly improved dispersibility in good solvent for the grafting polymer. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3842–3852, 2004 相似文献
7.
L. Fras-Zemljič P. Stenius J. Laine K. Stana-Kleinschek 《Cellulose (London, England)》2006,13(6):655-663
The research reported in this paper demonstrates that the capacity of cotton fibres to adsorb cationic surfactants as well as the rate of the adsorption process can be increased by adsorbing carboxymethyl cellulose (CMC) onto the fibre surfaces; in addition, the adsorption can be restricted to the fibre surface. CMC was deposited by means of adsorption from an aqueous solution. The adsorption of N-cetylpyridinium chloride (CPC) from an aqueous solution onto the CMC-modified fibres was measured using UV-spectrometric determination of the surfactant concentration in the solution. Adsorption onto the cotton fibres was studied in a weakly basic environment (pH 8.5) where cotton fibres are negatively charged and the CPC ion is positively charged. Modification of the fibres by adsorption of CMC introduces new carboxyl groups onto the fibre surfaces, thereby increasing the adsorption capacity of the fibres for CPC. The initial rate of adsorption of CPC increased proportionally with the amount of charge; however, this rate slowed down at high degrees of coverage on fibres with a high charge. The adsorption of cationic surfactant to the anionic surface groups was stoichiometric, with no indication of multilayer or admicelle formation. It was evident that the acidic group content of the fibres was the primary factor determining cationic surfactant adsorption to these fibres. 相似文献
8.
Choi SH Hwang YM Ryoo JJ Lee KP Ohta K Takeuchi T Jin JY Fujimoto C 《Electrophoresis》2003,24(18):3181-3186
Surface grafting of glycidyl methacrylate (GMA) on silica gel and a polyethylene bead was performed by radical polymerization and radiation-induced polymerization, respectively, in order to improve softness. Subsequently, diethylene triamine (DETA), triethylene tetraamine (TETA), and iminodiacetic acid (IDA) were introduced to the grafted GMA for use as affinity columns. The efficiency of the affinity column was investigated by use of bovine serum albumin (BSA) and hemoglobin (Hb) as model proteins. The affinity degree of BSA was higher than Hb for the DETA and TETA column, whereas the affinity degree of Hb was higher than BSA for the IDA column supported by silica gel. The affinity degree of BSA was higher than Hb for the DETA and TTA column supported by polyethylene (PE) beads. 相似文献
9.
Herv Cartier Guo-Hua Hu 《Journal of polymer science. Part A, Polymer chemistry》1998,36(15):2763-2774
Glycidyl methacrylate (GMA) is a very useful monomer as it bears an epoxy group which is capable of reacting with various other functional groups. However, its melt free radical grafting reactivity onto a polymer backbone is low. In this study, we show that the use of styrene (St) as a comonomer greatly promotes both GMA's grafting yield and grafting rate onto polyethylene (PE). It is proposed that, in the presence of St, the dominant mechanism of the free radical grafting of GMA onto PE is that St reacts first with PE secondary macroradicals and the resulting styryl macroradicals then copolymerize with GMA leading to grafted GMA. We also show that the contribution of St is not related to an improved solubility of GMA in the molten PE. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 2763–2774, 1998 相似文献
10.
This study demonstrates the surface modification of thermally expandable core/shell microspheres by grafting glycidyl methacrylate (GMA) using activators regenerated by electron transfer (ARGET) ATRP. To retain the expansion properties it was essential to minimize the shear forces, use solvents compatible with the microspheres and keep the reaction times short (three hours or less). Using microspheres with hydroxyl groups on the surface, it was found that after converting these to α-bromo esters, GMA could be grafted by ARGET ATRP using only 50 ppm of copper catalyst in toluene at 30 °C. Decent control of the polymerization was achieved with PMDETA as ligand reaching PDIs of 1.4 for the solution polymerization of GMA. When microspheres were present, the polymerization was less controlled with higher PDIs. The epoxide groups of the grafted microspheres were hydrolyzed by HCl in THF providing a hydrophilic surface of the microsphere. The expansion property of the microspheres was studied after each reaction step by thermal mechanical analysis, and it was found that the expansion capacity was well preserved with only limited negative effect on the microspheres. 相似文献
11.
Diethylenetriamine-grafted poly(glycidyl methacrylate) adsorbent for effective copper ion adsorption 总被引:3,自引:0,他引:3
Amine-functionalized adsorbents have attracted increasing interest in recent years for heavy metal removal. In this study, diethylenetriamine (DETA) was successfully grafted (through a relatively simple solution reaction) onto poly(glycidyl methacrylate) (PGMA) microgranules to obtain an adsorbent (PGMA-DETA) with a very high content of amine groups and the PGMA-DETA adsorbent was examined for copper ion removal in a series of batch adsorption experiments. It was found that the PGMA-DETA adsorbent achieved excellent adsorption performance in copper ion removal and the adsorption was most effective at pH>3 in the pH range of 1-5 examined. X-ray photoelectron spectroscopy (XPS) revealed that there were different types of amine sites on the surfaces of the PGMA-DETA adsorbent but copper ion adsorption was mainly through forming surface complexes with the neutral amine groups on the adsorbent, resulting in better adsorption performance at a higher solution pH value. The adsorption isotherm data best obeyed the Langmuir-Freundlich model and the adsorption capacity reached 1.5 mmol/g in the case of pH 5 studied. The adsorption process was fast (with adsorption equilibrium time less than 1-4 h) and closely followed the pseudo-second-order kinetic model. Desorption of copper ions from the PGMA-DETA adsorbent was most effectively achieved in a 0.1 M dilute nitric acid solution, with 80% of the desorption being completed within the first 1 min. Consecutive adsorption-desorption experiments showed that the PGMA-DETA adsorbent can be reused almost without any loss in the adsorption capacity. 相似文献
12.
Doc. Dr. Margarita Petkova Nedelcheva Dipl. eng. Georgi Vladimirov Stoilkow 《Colloid and polymer science》1977,255(4):327-333
Summary Polyacrylamide adsorption by sulphite bleached, sulphite unbleached and monocarboxyl-cellulose was investigated. The kinetics of the adsorption process was studied, the reaction order was established and the velocity constants, the velocity temperature coefficients and the activation energies were determined.Data were adduced about the physical type of PAA adsorption by the four cellulose materials. The adsorption equations were established for the temperature interval of 0 °C to 60 °C.
With 8 figures and 4 tables 相似文献
Zusammenfassung In vorliegender Arbeit wurde die Adsorption von Polyacrylamid auf gebleichtem und ungebleichtem Sulfitzellstoff, ungebleichtem Sulfatzellstoff und auf Monokarboxylzellulose untersucht. Es wurden auch die Kinetik des Adsorptionsprozesses studiert, die Reaktionsordnung, die Geschwindigkeits-Konstante und die Aktivierungsenergie festgestellt.Es wurden Tatsachen herangezogen, die die Adsorption von Polyacrylamid an Zellstoffen als physikalisch beweisen. Es wurden die Gleichungen der Adsorption im Temperaturinterval von 0 °C bis 60 °C aufgestellt.
With 8 figures and 4 tables 相似文献
13.
Raquel Martini Luis Serrano Silvia Barbosa Jalel Labidi 《Cellulose (London, England)》2014,21(3):1909-1919
Cellulose is one of the most abundant materials in nature. Besides its biological function, cellulose can be extracted from the cell wall and used in several industrial applications. Thus, it can be used in papers, pharmaceuticals, food, cosmetics and innovative materials such as nanocomposites, packaging, coatings and dispersion technology. With the aim of extending cellulose applications and producing so-called “smart” materials, new functionality can be introduced by physical or chemical modifications. Taking into account that capsaicin, the active component of chili peppers, is an excellent antifungal agent, a potential new material could be obtained by chemical reaction between this active compound and cellulose. In this work, capsaicin grafting onto cellulose using polycarboxylic acid as linking agent is proposed. The reaction occurrence was corroborated by Fourier transform infrared spectroscopy and UV–Vis spectrophotometry in reflectance mode. Modified cellulose with <2 wt% of capsaicin shows a strong change in antifungal activity with respect to the unmodified one. This activity was evaluated by the fungal growth inhibition test with two different fungi, Trametes versicolor and Gloeophyllum trabeum. Modified cellulose samples showed a high percentage of fungal growth inhibition, demonstrating the success of the cellulose modification and high antifungal power of the grafting molecule. 相似文献
14.
Mu-Shih Lin Chung-Song Huang 《Journal of polymer science. Part A, Polymer chemistry》1992,30(11):2303-2312
Allyl cellulose was synthesized by reacting cellulose with allyl bromide in homogeneous LiCl/DMAc solution containing NaOH powder. The degree of substitution (DS) per anhydroglucose (AHG) unit was determined by titrating the allyl cellulose with bromine in chloroform solution, and an allyl DS of 2.80 was found. Glycidyl cellulose was then prepared by reacting this allyl cellulose with peracetic acid in methylene chloride at ambient temperature for 6 days. The measured reaction rate constant was 1.33 × 10?3 min?1. The glycidyl cellulose thus obtained with a glycidyl DS of 2.58 was determined by titrating the product with perchloric acid in conjunction with tetrabutylammonium iodide. The 2.58 of glycidyl DS was also confirmed by 1H-NMR integration. Both allyl cellulose and glycidyl cellulose were analyzed and characterized with FTIR, 1H-NMR, 13C-NMR, TGA, and GPC. During epoxidation of allyl cellulose, possible side reaction leading to ester formation was evidenced from the continuous increase of vC? O at 1735 cm?1 in FTIR analyses. In addition, a bimodal distribution and a decreased molecular weight for glycidyl cellulose were found from GPC data, which might suggest a possible chain scission at the cellulosic ether linkage. © 1992 John Wiley & Sons, Inc. 相似文献
15.
Chi‐Hao Chen Wen‐Chien Lee 《Journal of polymer science. Part A, Polymer chemistry》1999,37(10):1457-1463
Particles of methyl methacrylate (MMA) and glycidyl methacrylate (GMA) copolymer having narrow size distributions were prepared by the method of dispersion polymerization. Results from the analysis of particle porosity and the correlation of specific surface area with the reciprocal of particle diameter suggest that the prepared particles were nonporous. The particle size was found to decrease from 4.2 to 2.1 μm with increasing the mass ratio of GMA/MMA from 0.1 to 0.75. Polymer particles having an average diameter falling in this range are suitable for being employed as the stationary phase in protein chromatography. The decrease in particle size when GMA was present could be due to the increase in adsorption rate of poly(vinyl pyrrolidone). The oligomer chains that were rich in GMA were more active for adsorbing and grafting PVP, compared with the moiety of MMA. An increase in the GMA/MMA ratio also leaded to a decrease in epoxy‐group density on the particle surface, since the reactivity of GMA was greater than that of MMA. Results of this work suggest that the influence of GMA/MMA mass ratio on the particle size and surface functionality of the nonporous particles was very significant. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1457–1463, 1999 相似文献
16.
Erick Hiriart-Ramírez Angel Contreras-García Maria José Garcia-Fernandez Angel Concheiro Carmen Alvarez-Lorenzo Emilio Bucio 《Cellulose (London, England)》2012,19(6):2165-2177
The aim of this work was to functionalize cotton gauzes with cyclodextrins in order to endow them with the ability to elute antimicrobial agents and to prevent infections. Gauzes were modified according to a two-steps approach: (1) pre-irradiation of the gauzes (Gammabeam) to graft glycidyl methacrylate (GMA), and (2) covalent binding of cyclodextrins (CDs) to the GMA-grafted gauzes. First the dependence of GMA grafting yield on the radiation dose (from 1 to 20 kGy) and the time of reaction was evaluated in detail. Anchorage of β-cyclodextrin (β-CD) and hydroxypropyl-β-cyclodextrin (HP-β-CD) was confirmed by FTIR, TGA, and 3-methylbenzoic acid sorption. Differently from pristine gauzes, CD-functionalized GMA-grafted gauzes were able to load an anionic antibiotic drug, specifically nalidixic acid, and to sustain the release for 6 h. Drug-loaded gauzes were tested in vitro against E. coli and the results prove the suitability of the functionalization approach to efficiently inhibit the growth of this microorganism. 相似文献
17.
RAFT of sulfobetaine for modifying poly(glycidyl methacrylate) microspheres to reduce nonspecific protein adsorption
下载免费PDF全文
![点击此处可从《Journal of polymer science. Part A, Polymer chemistry》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Jana Koubková Hana Macková Vladimír Proks Miroslava Trchová Jiří Brus Daniel Horák 《Journal of polymer science. Part A, Polymer chemistry》2015,53(19):2273-2284
The minimization of nonspecific protein adsorption is a crucial step in the development of bioseparation processes, immunoassays, and affinity diagnostics. Among the numerous biomaterials, polyzwitterions are known to effectively suppress protein and cell adhesion. This article describes the formation of monodisperse polymer microspheres coated with polysulfobetaine with the aim to limit nonspecific adsorption of bovine serum albumin (BSA) as a model protein. In this process, 2‐μm poly(glycidyl methacrylate) (PGMA) microspheres were prepared by dispersion polymerization. To render the microspheres hydrophilic and biocompatible, [3‐(methacryloylamino)propyl]dimethyl(3‐sulfopropyl)ammonium hydroxide (MPDSAH) was grafted from the surface by reversible addition‐fragmentation chain transfer (RAFT) polymerization. Elemental analysis of the modified microspheres revealed up to 20 wt % of poly{[3‐(methacryloylamino)propyl]dimethyl(3‐sulfopropyl)ammonimum hydroxide} (PMPDSAH). The microspheres were characterized in terms of particle size, morphology, and zeta potential. The amount of BSA nonspecifically adsorbed on the PMPDSAH‐modified microspheres decreased to half of that captured on the unmodified PGMA microspheres. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 2273–2284 相似文献
18.
This review paper briefly introduces the radiation chemistry of cellulose, the different grafting techniques used, and the methods of characterization of the grafted material. It shows the application of the grafted polymer for the removal of water pollutants and also the regeneration of the adsorbent. 相似文献
19.
Pradeep K. Dhal M. S. Ramakrishna G. N. Babu 《Journal of polymer science. Part A, Polymer chemistry》1982,20(6):1581-1585
A newer approach to obtaining acrylic thermoset polymers with adequate hydrophilicity required for various specific end uses is reported. Glycidyl methacrylate (GMA) was copolymerized with n-butyl acrylate (n-BA), isobutyl acrylate (i-BA), and 2-ethylhexyl acrylate (2-EHA) in bulk at 60°C. with benzoyl peroxide as free radical initiator. The copolymer composition was determined from the estimation of epoxy group. Reactivity ratios were calculated by the Yezrielev, Brokhina, and Roskin method. For copolymerization of GMA (M1) with n-BA (M2) the reactivity ratios were r1 = 2.15 ± 0.14, r2 = 0.12 ± 0.03; with i-BA (M2) they were r1 = 1.27 ± 0.06, r2 = 0.33 ± 0.031; and with 2-EHA (M2) they were r1 = 2.32 ± 0.14, r2 = 0.13 ± 0.009. The reactivity ratios were the measure of distribution of monomer units in a copolymer chain; the values obtained are compared and discussed. 相似文献
20.
Wang Shuo Chen Xu Li Ze Zeng Weiwei Meng Dekai Wang Yonggui Xiao Zefang Wang Haigang Liang Daxin Xie Yanjun 《Cellulose (London, England)》2022,29(16):8843-8861
Cellulose - In the preparation of hydrogels for removing dye pollutants from wastewaters, cellulose, a natural polymer, has become a popular raw material of late. In an effort to develop adsorbents... 相似文献