Starch and cellulose, earth's most abundant biopolymers, are of tremendous economic importance. Over 90% of cotton and 50% of wood are made of cellulose. Wood and cotton are the major resources for all cellulose products such as paper, textiles, construction materials, cardboard, as well as such c...

... sulfite pulp which to pro- duced In the form of cardboard sheets. Instead of the usually recommended (16] cellulose of the Arkhangel' Paper ...

... properties between cellulosic fibers and thermoplastics was studied. Acetylation and beat treatment were applied to modify the ... microbond test method. The test results indicate that acetylation increas...

... CHEMICAL CONTAMINATION, SPECIFICATIONS, CITRIC ACID, COLORS, NITRATES, CELLULOSE ACETATES, NAVAL PROCUREMENT ...

Low-Level Waste buried on the SRS contains cellulosic materials, Including wood, paper, and cardboard. Once buried, these materials are expected to degrade to form cellulose degradation products (CDP). Such materials are expected to influence radionuclide...

A combination of adsorption and calorimetric measurements was made to study structuring of water at cellulose acetate surfaces of varying polarity. In this work cellulose acetate powders with varying degrees of acetylation were used. The results obtained ...

... mixed esters can be prepared in a wide range of amounts of substitution of both acetate and nitrate groups either through acetylation of cellulose ...

... encourage mold to grow. Wet cellulose materials, including paper and paper products, cardboard, ceiling tiles, wood, and wood products, ... low nitrogen content, such as fiberboard, gypsum board, paper, dust, and lint. Growth occurs when there is ...

The authors studied acetylation of bacterial cellulose (BC) nanofibers to widen the applications of BC nanocomposites in optoelectronic devices. The slight acetylation of BC nanofibers significantly reduces the hygroscopicity of BC nanocomposites, while maintaining their high optical transparency and thermal stability. Furthermore, the ...

A novel and straightforward method for the surface acetylation of cellulose nanowhiskers by transesterification of vinyl acetate is proposed. The reaction of vinyl acetate with the hydroxyl groups of cellulose nanowhiskers obtained from cotton linters was examined with potassium carbonate as catalyst. Results indicate that during the ...

Paper and cardboard stand for the major biodegradable organic fraction of most of municipal solid waste (MSW). This article aims at discussing the possible positive impact of a thin shredding of this fraction on its biodegradability under mesophilic anaerobic conditions, either for landfilling or for digestion in industrial reactors. For that purpose, BMP tests were performed ...

A polymeric membrane, composed of a homogenous mixture of (1) a hydrophilic resin which is (a) partially acetylated cellulose in which from about 50 to less than 100 percent of the hydroxyl groups are acetylated, (b) polyvinyl acetate, (c) hexadimethrine ...

The antimicrobial activity of lysozyme derives from the hydrolysis of the bacterial cell wall polysaccharide at the glycosidic bond that links N-acetyl-glucosamine and N-acetyl-muramic acid. Maintaining the activity of lysozyme while bound to a cellulose substrate is a goal toward developing enzyme...

A two-stage process for the enzymatic conversion of cellulose to ethanol is proposed as an alternative to currently incomplete and relatively slow enzymatic conversion processes employing natural insoluble cellulose. This alternative approach is designed to promote faster and more complete conversion of cellulose to fermentable sugars ...

Bacterial cellulose (BC) nanofibers were acetylated to enhance the properties of optically transparent composites of acrylic resin reinforced with the nanofibers. A series of BC nanofibers acetylated from degree-of-substitution (DS) 0 to 1.76 were obtained. X-ray diffraction profiles indicated that acetylation ...

Hyperfiltration (Reverse Osmosis) research in the following areas is reported: Asymmetric Membranes Prepared from Maleinated Acetyl Cellulose; Hyperfiltration in Charged Membranes: Prediction of Salt Rejection from Equilibrium Measurements; and Streaming ...

The acetylation of commercial cotton samples with acetic anhydride without solvents in the presence of about 5% 4-dimethylaminopyridine (DMAP) catalyst was followed using Fourier transform infrared (FTIR) and 13C MAS NMR spectroscopy. This preliminary investigation was conducted in an effort to develop hydrophobic, biodegradable, cellulosic materials for ...

Cellulose acetate can be effectively crosslinked with hexamethoxymethyl melamine, acetyl acetonate titanium chelate, sodium dichromate, or lead oxide to prevent desalination membrane compaction. Only pigment reinforcement was promising in preventing the c...

A method for measuring the resistance change of a film with time was used to determine the diffusion and apparent permeability coefficients of sodium chloride in the two polymeric films. The results with cellulose diacetate (CDA, 39.8% acetyl) were compar...

This program represented a continuation of previous work which showed that cellulose triacetate (CTA), with acetyl content in the range of 43% to 44%, should have the required long-term salt rejection capability needed for single stage sea water demineral...

Fourier transform infrared (FTIR) and 13C MAS NMR spectroscopy have been used to investigate the acetylation of raw cotton samples with acetic anhydride without solvents in the presence of different amounts of 4-dimethylaminopyridine (DMAP) catalyst. This is a continuation of our previous investigation of acetylation of commercial cotton in an effort to ...

employees in recycling) Cardboard Recycling Program for many years. ... Number and Location of Existing Cardboard Recycling Carts ...

In this work an optimization of the solvent-free acetylation of cellulose with acetic anhydride under microwave heating with iodine as a catalyst was performed. The optimized parameters included the microwave irradiation power from 300 W to 800 W, the reaction time between 5 to 40 min, the reaction temperature from 80 to 130 degrees C, and the amount of ...

Twenty-five linear feet of a low-level beta-gamma waste trench was excavated fourteen years after the waste was buried. The waste included wood, steel, plastics, cotton cloth, rubber, and paper. Cardboard boxes not enclosed in plastic were the only materials to deteriorate visibly. Apparently, decades would be required for all cellulose materials to ...

In the present study, novel bionanocomposite materials with tunable properties were successfully prepared using a poly(lactic acid) (PLA) matrix and acetylated microfibrillated cellulose (MFC) as reinforcing agent. The acetylation of MFC was confirmed by FTIR and (13)C CP-MAS NMR spectroscopies. The grafting of ...

The crystal structure of cellulose triacetate 1 (CTA 1), obtained by heterogeneous acetylation of ramie cellulose 1, was determined by a combined X-ray diffraction and stereo chemical model analysis. The crystal structure of regenerated cellulose 2 (Fortisan) was solved by a combined stereochemical packing ...

A heretofore uninvestigated approach to the production of cellulose acetate is the acetylation of mechanical pulp with subsequent isolation of the cellulose derivative by differential solubility. The mechanical pulp is produced by refining aspen wood chips in a disc-refiner. Two conventional acetylation techniques, ...

Acetyltransferase was isolated by histone-Sepharose affinity chromatography from human cord blood red cells. The enzyme was detected only in very young red cells. The semipurified enzyme and (/sup 14/C)acetyl-CoA were used to acetylate isolated Hb F tetramer and ..cap alpha.. and ..gamma.. subunits. The in vitro acetylated products ...

Results of graft polymerization of acrylonitrile (AN) or styrene onto cellulose acetate (with an acetyl content of 52.8%) obtained from several methods using a 1500-c Co/sup 60/ gamma -ray source are discussed. With the preirradiation method. cellulose acetate was irradiated in the presence of air, and the quantity of ...

Batch hydrolysis kinetics of paper birch (Betula papyrifera) xylan and its associated acetyl groups in dilute sulfuric acid have been measured for acid concentrations of between 0.04 and 0.18M and temperatures of between 100 and 170 degrees C. Only 5% of the cellulose was hydrolyzed for up to 85% xylan removal. Rate data were correlated well by a parallel ...

which depolymerizes lignin and polyphenols; N-acetyl-glucosaminidase which hydrolyzes chitin metabolites extracellular enzymes capable of degrading lignin, cellulose, and organic N, which are dominant components

The ethyl-acetyl cellulose/dichloroacetic acid anisotropic solution film could form pseudoisotropic and oily streak textures in nature and the layers of ordered polymer chains tend to being parallel to the glass slide in the former texture and perpendicul...

Mechanical lapping and polishing of silicate crystals, mounted in epoxy resin, ... ed in plastic and etched. Figs. 5 and 6 represent one half of the olivine ... The surfaces were replicated with acetyl cellulose plastic sheet dipped in ...

An experimental study was carried out to establish whether the draft EEC method for the determination of the global migration of constituents from plastics packaging materials into fatty food simulants could be applied to all plastics, including lacquers and laminates. Some difficulties were encountered in the use of the EEC method for melamine, for hotmelt-coated packaging materials and for ...

Recombinant acetyl xylan esterase (rAXE) of Aspergillus ficcum catalyzed the synthesis of peracetic acid (PAA) from ethyl acetate and hydrogen peroxide. Ten micrograms of rAXE catalyzed the synthesis of 1.34mM of PAA, which can be used for the pretreatment of cellulosic biomass in situ. PMID:21824816

The X-ray diffraction diagrams of cellulose polymorphs IV/sub I/ IV/sub II/ appear identical, suggesting that the two polymorphs possess the same crystal structure. However, upon heterogeneous acetylation, cellulose IV/sub I/ produces the crystalline form of cellulose triacetate I (CTA I), whereas ...