References Yyd
1. Chanzy H 1980 J Polym Sci, Polym Phys Ed 18 1137 2. Chanzy H, Nawrot S, Peguy A, Smith P 1982 J Polymer Sci 20 1909 3. Marini I, Brauneis F 1996 Textilveredelung 31 182 4. Firgo H, Eibl M, Eichinger D 1995 Lenzinger Ber 75 47 5. Brandner A, Zengel HG 1980 German Patent DE-OS 3,034,685 Chem Abstr 97 7727d CA 6. Ringel C 1969 Z Chem 9 188 7. Buijtenhuis FA, Abbas M, Witteveen AJ 1986 Papier 40 615 8. Rosenau T, Potthast A, Sixta H, Kosma P 2001 Progr Polym Sci 26 1763 9. Rosenau T, Potthast A,...
PolyEthylene GlycolAlkyl Dextran Ether DexPEGiCn for Drug Delivery
Amphiphilic poly ethylene glycol -alkyl dextran ethers are emerging as vehicles in the oral delivery of poorly water soluble drugs 251, 268, 269 . They form polymer micelles of low critical association concentrations CAC and small micelle sizes in aqueous solution. Particulate delivery systems lead to an enhancement of the absorption efficiency and bioavailability of highly lipophilic drugs orally applied, and provide the drug with some level of pro tection against degradation within the GI...
NNCarbonyldiimidazole CDI as Esterification Reagent
A method with an enormous potential for dextran modification is the homogeneous one-pot synthesis after in situ activation of the carboxylic acids with CDI, which is a rather well known technique in general organic chemistry and was published in 1962 197 . It is especially suitable for the functionalisation of the biopolymers, because during conversion the reactive imidazolide of the acid is generated and only CO2 and imidazole are formed as by-products Fig. 29 . The reagent and by-products are...
References Yrk
1. Bledzki AK, Gassan J 1999 Prog Polym Sci 24 221 2. Eichhorn SJ, Baillie CA, Zafeiropoulos N, Mwaikambo LY, Ansell MP, Dufresne A, Entwistle KM, Herrera-Franco PJ, Escamilla GC, Groom L, Hughes M, Hill C, Rials TG, Wild PM 2001 J Mater Sci 36 2107 3. Mohanty AK, Misra M, Hinrichsen G 2000 Macromol Mater Eng 276 277 1 4. Mohanty AK, Misra M, Drzal LT eds. 2005 Natural fibers, biopolymers, and biocomposites. CRC, Boca Raton 5. Hon DN-S 1993 In Seymour RB, Porter RS eds Manmade fibers, their...
Analysis of Oxidized Functionalities in Cellulose
Antje Potthast Thomas Rosenau Paul Kosma K Department of Chemistry, Christian-Doppler-Laboratory of Pulp Reactivity, University of Natural Resources and Applied Life Sciences, Member of the European Polysaccharide Network of Excellence EPNOE , 1 Oxidized Groups in 1.1 A Survey of Oxidative 1.1.3 Irradiation 1.1.4 Aging Processes 1.2 Carbonyl Groups in 1.2.1 The Reducing End Group REG 1.2.2 2,3-Dialdehyde 1.2.3 6-Aldehyde 1.2.4 Keto Groups 1.2.5 The Nature of Carbonyls in 1.3 Carboxyl Groups in...
Diethylaminoethyl DEAE Dextran
2- Diethylamino ethyl dextran DEAE dextran is synthesised by reaction of dextran with 2-chloroethyl diethylammonium chloride in the presence of NaBH4 in an alkaline solution at 85-90 0C Fig. 45 . Fig. 45 Synthesis and structure of DEAE dextran containing 2- diethylamino ethyl A and B groups DEAE dextran contains three basic groups with different pKa values Fig. 45 . One 2- diethylamino ethyl, A consists of a tertiary amino group with a pKa of 9.5. The other two moieties are B a tertiary amino...
NMR Spectroscopic Characterisation of Dextran
Beside chemical modification and degradation of the polymer backbone, NMR spectroscopy is a capable method for structure determination of dex-tran 29-32 . Moreover, from the experiences of the authors in the field of structure characterisation of polysaccharides and their derivatives, NMR spectroscopy is one of the most important methods for obtaining detailed structure information 33 . The chemical shifts of the hydrogen and carbon atoms NMR spectra measured in DMSO-d6 of the glucose unit in...
Carboxymethyl Dextran CMD
Carboxymethylation of dextran in water organic solvent mixtures using monochloroacetic acid MCA under strong alkaline conditions leads to CMD with good reproducibility Fig. 38 . A DS of up to 1.0 is obtained in one step by applying optimised reaction conditions 3.8 M aqueous NaOH, reaction temperature of 60 C for 90 min in tert-butanol water or isopropanol water 85 15 v v mixtures Table 12 219 . The DS of CMD can be increased by repeated carboxymethy-lations. CMD with DS 1.5 was realised by...
Zeolite Hybrids
Natural and synthetic zeolites, a family of aluminosilicates with pores and cavities in the range 0.4-1.5 nm, are well-known heterogeneous catalysts and sorbents. Zeolite-incorporated cellulosic fibers and membranes could be suitable for medical antibacterial materials, deodorizers, absorbent pads, sanitary napkins, gas separators, ion exchangers, and so forth however, the complete and continual use of the whole zeolite surface is not easy in the grossly combined form with such a fibrous...