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A new process for the production of nanocellulose from selected cellulose-containing natural materials has been developed. The liquefaction reaction, using glycols and mild acid catalysis (methane sulphonic acid), was applied to four model materials, namely cotton linters, spruce wood, eucalyptus wood and Chinese silver grass. The process contains only four steps, the milling, the glycolysis reaction, centrifugation and final rinsing with an organic solvent. The nanocrystalline cellulose recovery was between 56% and 75%. The crystallinity index was greater than that of the starting materials due to the liquefaction of lignin, hemicelluloses and amorphous cellulose. The final product was a stable, highly concentrated nanocrystalline cellulose suspension in the organic medium. The liquid residue, after the liquefaction of the cotton linters contained significant quantities of levulinic acid. Different sugars were identified in the liquid residues that were derived from cellulose and hemicelluloses during the liquefaction reaction. [ABSTRACT FROM AUTHOR]

Abstract: The aim of the presented work was to replace phthalate based plasticizers with environmentally friendly materials to provide similar properties for poly(vinyl acetate) (PVAc) adhesives. Polyesters synthesized from the liquefied wood (PE-LW) and depolymerized polyethylene terephthalate (PE-PET) were used as renewable raw materials and evaluated as plasticizers used in PVAc dispersion adhesives for flooring applications. As a reference plasticizer, 1,2,3-triacetoxypropane was used. PVAc adhesives were evaluated with respect to solids content, viscosity, glass transition temperature (T g), tensile shear strength and binding strength. TGA analysis showed significant differences between the thermal stability of added polyesters and the commercial plasticizer. Samples prepared with PE-PET exhibit the best thermal stability even with an increase of 25% PE-PET. The addition of coalescing agents or plasticizers leads to a temporary softening of the PVAc polymer and a decrease in the glass transition temperature. The type and content of plasticizer have great influence on wood–wood binding strength, tensile strength and elongation. The requirements for the mechanical properties of adhesives were fulfilled by the compositions containing 8.8% (w/w) of PE-PET and 20% (w/w) of PE-LW. [Copyright &y& Elsevier]

Abstract: In our research, we have utilized high energy ultrasound for the liquefaction of different lignocellulosic materials, wood wastes in particular. We developed a highly efficient way of transforming this biomass waste into valuable chemicals. It was found, that the reaction yield in all experiments was high and that the reaction times were shortened up to nine times when using the ultrasound process with smaller residual particles and with no influence on the hydroxyl number of the final products. The use of the ultrasound process inhibits the formation of the large molecular structures during the liquefaction from the degradation products, by keeping the reactive segments apart and due to such a short reaction time being used. The short reaction time and subsequent low energy consumption for the liquefaction reaction leads to the creation of the new method for the transformation of the wood waste materials into valuable chemicals. [Copyright &y& Elsevier]

Abstract: A blend of spruce (Picea spp.) and fir (Abies spp.) sawdust was liquefied by an optimized technique in the presence of multifunctional alcohols and p-toluene sulfonic acid monohydrate as a catalyst. The lignin behaviour during wood liquefaction was studied at different reaction times. Samples prepared by the new separation procedure were characterized by quantitative 31P, 13C NMR and by size-exclusion chromatography. The final products showed increased molar masses indicating the condensation reactions between the lignin and the multifunctional alcohols. Aliphatic chains were found to be incorporated into the lignin network after liquefaction. The resulting polymer showed an increased content of aliphatic hydroxyl groups with respect to the starting material and a high degree of solubility in multifunctional alcohols. [ABSTRACT FROM AUTHOR]

Abstract: Different types of southern European hardwoods and softwoods were subjected to a liquefaction process with glycerol/diethylene glycol. The liquefied spruce wood was reacted in a condensation reaction in the hot press with different melamine–formaldehyde and melamine–urea–formaldehyde resin precursors and used as adhesives for wood particle boards. The mechanical properties of these particle boards and the determination of formaldehyde release, proved that addition of 50% of the liquefied wood to such resin precursors caused the product to meet the European standard quality demands for particle boards. Up to 40% reduction of the formaldehyde emission was achieved. The temperature of the press unit was lowered from 180°C to 160°C with no significant influence on the mechanical properties. On the basis of the presented results it was possible to conclude that liquefied wood can be used as substitute for synthetic resin precursors in adhesives that are used for the particle board production. [Copyright &y& Elsevier]

Abstract: A study of gloss reduction of powder coatings was performed using different waxes, fillers and non-compatible polymer resins (matting hardeners). Coatings with reduced surface smoothness were analysed. Scanning electron micrographs were taken to visualize the surfaces. All of the applied matting additives changed the surface profile of coating. The most interesting surface structural form is provided by wax particles. The average size of these forms was calculated by applying image analysis to some sample micrographs. The surface shape of all of the prepared coatings was analysed using surface profile measurements. Two parameters of these profiles were determined, the average roughness and the mean spacing between the surface peaks. The influence of several physical surface parameters on specular gloss characteristics is discussed. [Copyright &y& Elsevier]

Abstract: Different polymers with various chemical and physical properties are used as a binder in pigmented coatings. The etching rate of these coatings with neutral oxygen plasma depends on the nature of the applied binder. To optimize the process, the chemical reaction of the oxygen plasma with the binder should be analyzed. The etching of a two-component polyester–polyisocyanate system was analyzed for these reasons. A low etching rate was observed when the exposure time was not longer than 100s. No differences in the chemical structure of the etched layer were observed by the infrared analysis under these conditions. At longer exposure times a rapid increase of etching efficiency occurs where the chemical structure of the polymer changes appreciably. The infrared spectra show the partial breaking of cross-links between both components. The abrupt change in the chemical structure of the polymer corresponds to the rapid increase in etching efficiency. Practically no further changes were observed at longer exposure to the neutral oxygen plasma. [Copyright &y& Elsevier]

Assessment of the state of a pigment dispersion in powder coatings is hindered by the lack of a simple and effective method of evaluation, particularly during the production process. A method for evaluating dispersion quality in cured powder coatings or in samples taken immediately after the extrusion process is described in this paper. Quantitative information of pigment dispersion were obtained using plasma etching-SEM-image analysis. In order to correlate the differences in the extrusion equipment and, consequently, the energy input of the dispersion process, two different formulations were studied, each prepared using three different extrusion units. The procedures are described in detail and the results are compared to those obtained using colour difference measurements. Pigment size distribution plots correlate well with measured colour differences and with the energy inputs of the different extrusion units used. [Copyright &y& Elsevier]

Eco-friendly “green” nano composites were fabricated from potato starch and cellulose nanofibers from pineapple leaf. Nanocomposites of starch/cellulose nanofibers were prepared by solution mixing followed by casting. The investigation of the viscoelastic properties confirms starch macromolecular chain confinement around the nano scale cellulose surface, superior dispersion and very good interaction between thermoplastic starch and cellulose nanofibers. The degree of chain confinement was quantified. The chain confinement was associated with the immobilization of the starch macromolecular chains in the network formed by the nano-scale cellulose fibers as a result of hydrogen boding interactions. From the results, it was assumed that the starch glycerol system exhibits a heterogenous nature and cellulose nanofibers tend to move towards glycerol rich starch phase. Barrier properties also improved with the addition of nanofiller up to 3 wt.% but further addition depreciated properties due to possible fiber agglomeration. The kinetics of diffusion was investigated and typical kinetic parameters were determined and found that the nanocomposites follow pseudo fickian behaviour. The outcome of the work confirms that the prepared nanocomposites films can be used as a swap for packaging applications. [ABSTRACT FROM AUTHOR]

Innovative lignocellulosic biofuel, obtained through solvolysis of spruce wood in multifunctional alcohols was tested in an experimental turbine engine with different primary air temperatures. Variation of primary air temperature was used to emulate two types of microgas turbine generators – fully recuperated and simple cycle setups resulting in different temperatures of combustion chamber intake air. Results indicate that different temperatures, velocities, and flow conditions in primary zone of combustion chamber strongly influence on droplet penetration depth and rate of mixture formation as well as emissions formation. For the innovative lignocellulosic biofuel emission trends of CO and THC were found to be significantly higher in simple cycle mode, whereas no influence of operation mode was observed for baseline diesel fuel. NO x emissions of innovative biofuel generally increased in regenerative cycle mode and also became sensitive on turbine inlet temperature, with similar trends being observed with diesel fuel. In the case of innovative fuel, deposits of char and polymerized fuel were observed on the combustor walls after operation in simple cycle mode, whereas in regenerative cycle mode, only small amounts of ash deposits were found on hot path surfaces, indicating beneficial influence of high primary air temperatures on combustion efficiency of innovative fuel. [ABSTRACT FROM AUTHOR]

Abstract: The paper reports foremost the results of a successful combustion of an innovative lignocellulosic biofuel in a gas turbine. The fuel was processed through liquefaction of lignocellulosic materials with polyhydroxy alcohols in an acid catalyzed reaction. The liquefaction process features: high efficiency, high liquid yields and inexpensive, easily available process equipment. For the purpose of this analysis the following were developed: an experimental gas turbine with internal combustion chamber, a preheated pressurized fuel supply system with swirl-air fuel injector and a heat exchanger to obtain high primary air temperatures. The paper gives results on the emissions of CO, THC, NOx and soot. For the purpose of benchmarking the turbine was also run on diesel fuel. The paper presents analyses of the underlying phenomena with which it aims to provide guidelines for improvements in the fuel processing and in the experimental equipment. It has been shown that direct utilization of this innovative lignocellulosic biofuel gives promising results. Although the CO and THC emissions are higher compared to the benchmark diesel results it has been shown that both emissions decrease with increased turbine inlet temperature and with the increased fuel preheat temperature, due to a very high viscosity of the fuel. It is additionally shown that NOx emissions are low and comparable to those of the diesel fuel, whereas soot emissions are very low for both fuels. [Copyright &y& Elsevier]

The amorphization of indomethacin was induced by milling. The mass fraction of the amorphous phase in the drug milled for various time intervals was determined with differential scanning calorimetry (DSC). Because the surface fraction amorphized by milling can be much higher than the mass fraction, which can have a large impact on the powder properties, a method for quantification of surface fraction amorphized by milling using inverse gas chromatography (IGC) was developed. A calibration curve was constructed by mixing completely amorphous indomethacin (obtained after milling for 120 min) with various amounts of the initial crystalline sample. Linear part of the curve was then used to quantify the surface amorphous content of samples milled for different time intervals. Surface and mass amorphization kinetics were determined and fitted to a first-order model. It was found that the surface amorphization rate is an order of magnitude higher than the mass amorphization rate. Results confirmed that IGC is a sensitive method for detection and quantification of the fraction of amorphous surface of milled indomethacin powder. If suitably combined with other techniques, this method represents a relatively general approach for the localization and quantification of the surface amorphous fraction in crystalline substances that transform into amorphous ones upon intensive milling. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99: 1968–1981, 2010 [ABSTRACT FROM AUTHOR]

In this research work, we propose a synergistic effect of a green crosslinker and cellulose nanomaterial on the crystallinity, viscoelastic, and thermal properties of starch nanocomposites. A disaccharide derivative was used as a bio crosslinker and nanofiber from pineapple leaf as a reinforcing phase for starch. Sucrose was oxidised using periodate, that can selectively oxidise the vicinal hydroxyl group of sucrose and form tetra aldehyde derivative. Crystallinity of films after crosslinking decreased with successive addition of crosslinker. The melting temperature of films increased because of formation of more dense structure after crosslinking. Morphological investigations were analysed by atomic force microscopy. Polymer chain confinement and mechanics were quantified. The crosslink densities of the films were calculated using two models, phantom model and affine model, using storage modulus data. By using very low amount of crosslinker and nanoreinforcement, the properties of thermoplastic starch were significantly improved. Unlabelled Image [ABSTRACT FROM AUTHOR]