Infrared cellulose polymer

In a typical experiment the isocyanate (0.006 moles) was reacted with 1.5 g of the polysaccharide in 150 ml of a 5% LiCl/ N,N-dimethylacetamide solution at 90°C under nitrogen for two hours. The appearance of a strong infrared absorbance at 1705 cm l was an indication of carbamate formation. The derivatized polymer was isolated as a white powder by precipitation of the reaction solution into a nonsolvent such as methanol. Alternatively thin films were cast directly from solution the lithium salt could be removed by rinsing with acetone. Figure 1 illustrates the reaction of cellulose with phenyl isocyanate. 

Rossi et al. [30] evaluated rheologically mucins of different origin with polyacrylic acid and sodium carboxymethyl cellulose. The same group also reported a novel rheological approach based on a stationary viscoelastic test (creep test) to describe the interaction between mucoadhesive polymers and mucins [31,32]. Jabbari et al. [33] used attenuated total-reflection infrared spectroscopy to investigate the ehain interpenetration of polyaciylic acid in the mucin interface. 

Applications of ESR spectroscopy to investigations of free-radical initiated copolymerization reactions of cellulose with vinyl monomers have been reported (1, 2). NMR and infrared spectroscopy have been used to examine products obtained from degradation of cellulose copolymers to characterize the nature of the chemical bonds between cellulose and polyvinyl polymer (35, 42). Covalent bonds were indicated in most cases. 

The degradation of the cellulose fraction of the copolymer and subsequent recovery of the polyvinyl polymer have often been used to characterize the polymer. For example, cellulose may be acetylated and acid hydrolyzed to remove it from the copolymer. Then the recovered polymer can be dissolved, in solvent normally used for the polymer, and i the molecular weight of the polymer determined viscometrically (12, 42). As reported previously for polymers, such as polyacrylonitrile, a functional group on the polymer may be altered during the fractionating. These changes have been determined by infrared spectroscopy. For free-... 

Study of the crystal structure of polysaccharides, particularly of cellulose, has provided the main use for polarized infrared radiation in connection with carbohydrate spectra. Since this is another technique whereby band assignments can be made, the basic steps involved will be described in a simplified manner with reference to a polymer sample having uniaxial orientation. This is a common type of orientation, characteristic of fibers,... 

C.Q. Yang. Infrared spectroscopy studies of the effects of the catalyst on the ester cross-linking of cellulose by poly(carboxylic acids). J. Appl. Polym. Sci., 1993, 50(12), 2047-2053. 

C. Y. Liang and R. H. Marchessault, Infrared spectra of crystalline polysaccharides. I. Hydrogen bonds in native celluloses, J. Polym. Sci, 37 (1959) 385-395. 

Sammon C, Bajwa G, Timmins P, Melia CD (2006) The application of attenuated total reflectance Fourier transform infrared spectroscopy to monitor the concentration and state of water in solutions of a thermally responsive cellulose ether during gelation. Polymer... 

Preparations of azide derivatives from styrene-maleic anhydride copolymers, cellulose, and gelatin by attaching aromatic azide compounds are described in the literature. Most of the resultant polymers crosslink rapidly when exposed to light of 260 wavelength. Also, as much as 90% of the hydroxy groups of poly(vinyl alcohol) can be esterified withp-azido-benzoyl chloride. These reactions must be carried out in mixtures of chloroform and aqueous sodium hydroxide. Based on infrared spectroscopy, the following crosslinking mechanism was proposed ... 

Infrared spectroscopy is a useful tool to identify functional groups through vibrational frequencies in polymers to evaluate changes in structure This research was focused in graft copolymerization of Hydroxyethyl methacrylate (HEMA) onto chicken feathers fibers (CFF) and carboxymethyl cellulose (CMC), evaluating effect of reaction conditions (time reaction, monomer concentration, initiator concentrations) on grafting yield and probe presence of HEMA in copolymers by means Infrared Spectroscopy (IR). 

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