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Isomerization of the olefin from cis to trans configuration is often a desirable reaction pathway that leads to products with different properties and chemical reactivities. In this work, we report a novel process involving the use of boron trifluoride diethyl etherate, BF 3 ·O(C 2 H 5) 2, in supercritical CO 2 that converts a compound with an isolated cis to a trans olefin in quantitative yield. No polymerization was observed. The utility of this reaction has been demonstrated by the conversion of jojoba oil (a natural wax ester, comprising a monoester of long-chain fatty acids with cis olefins) to its trans isomers. Jojoba oil is liquid at room temperature with a melting point of about 10 °C; the reacted product is a solid with a melting point of 37.6 °C (around the normal human body temperature). The simplicity of the reaction and the use of supercritical CO 2 are the attractive features of this reaction. [Display omitted] • Low cost of Lewis acid was used for isomerization of jojoba oil. • Supercritical CO 2 has been applied as a green medium. • Trans Solid isomer of jojoba oil that may be used in the cosmetic and food areas in view of its melting point (37.5 °C). • It is possibility for further derivatization due to the trans olefin configuration. [ABSTRACT FROM AUTHOR]

Soy and cottonseed proteins appear promising as sustainable and environment-friendly wood adhesives. Because of their higher cost relative to formaldehyde-based adhesives, improvement in the adhesive performance of proteins is needed. In this work, we evaluated the adhesive properties of soy and cottonseed protein formulations that included phosphorus-containing acids and esters. For cottonseed protein isolate, most of these additives improved dry adhesive strength, with methylphosphonic acid, phosphorous acid, and phosphoric acid increasing the dry strength by 47, 44, and 42%, respectively, at their optimal concentrations. For soy protein isolate, these additives did not show significant benefits. The phosphorus-containing additives also improved the hot water resistance of the cottonseed protein formulations but showed either no effect or a negative effect for the of soy protein formulations. Thus, the combination of cottonseed protein with phosphorus additives appears to be attractive as wood adhesives. [ABSTRACT FROM AUTHOR]

Soy protein is currently being used commercially as a “green” wood adhesive. Previous work in this laboratory has shown that cottonseed protein isolate, tested on maple wood veneer, produced higher adhesive strength and hot water resistance relative to soy protein. In the present study, cottonseed protein and soy protein isolates were tested on different wood types, and cottonseed protein again showed better performance relative to soy protein. Furthermore, the effects of several protein modifiers were evaluated, including amino acids, fatty acids, and other organic molecules with cationic or anionic charges. Aspartic acid, glutamic acid, acetic acid, butyric acid, and adipic acid gave improved performance when included with cottonseed protein isolate whereas no significant effect was observed on soy protein isolate. Both dry adhesive strength and hot water resistance were tested. The enhanced performance observed with these additives provides an additional incentive for the use of cottonseed protein in this application. [ABSTRACT FROM AUTHOR]

As an environmentally friendlier alternative to adhesives from petroleum feedstock, soy proteins are currently being formulated as wood adhesives. Cottonseed proteins have also been found to provide good adhesive properties. In at least some cases, cottonseed proteins appear to form greater shear strength and improved hot water resistance compared with soy proteins. In the present study, blends of soy and cottonseed proteins were prepared, and their adhesive properties were found to decrease steadily with increased levels of soy protein in the formulations. In addition, cottonseed- and soy-protein based adhesives were also formulated with xylan, starch, or celluloses to determine the influence of polysaccharide fillers on protein-based adhesive properties. In some cases, adhesive shear strength was retained even when the cottonseed or soy protein was mixed with up to 75% polysaccharide. For cottonseed protein/polysaccharide formulations, hot water adhesive resistance was retained when the blend contains about 50% polysaccharides. Soy protein formulations and its polysaccharide blends generally exhibited somewhat lower hot water resistance. In view of the ability of cottonseed protein/polysaccharide blends to retain shear strength and hot water resistance properties, these blends may provide an opportunity to decrease the amount of protein used in adhesive formulations, thereby decreasing cost. [ABSTRACT FROM AUTHOR]

The thermal and catalytic processes of converting waste plactics into fuels are promising techniques to eliminate the refuse which otherwise is harmful to the enivironment, and decrease the dependence on fossil fuels. Thermal degradation decomposes plastic into three fractions: gas, crude oil, and solid residue. Crude oil from non-catalytic pyrolysis is usually composed of higher boiling point hydrocarbons. The optimization of conversion parameters such as the choice of catalyst, reactor design, pyrolysis temperature, and plastic-to-catalyst ratio plays a very important role in the efficient generation of gasoline and diesel grade fuel. The use of a catalyst for thermal conversion lowers the energy required for conversion, and the catalyst choice is important for efficient fuel production. The suitable selection of catalysts can increase the yield of crude oil with lower hydrocarbon content. Co-pyrolysis of plastics with coal or shale oil improves crude oil quality by decreasing its viscosity. A large number of publications have appeared on various processes, and continued improvements and/or innovations are expected in the future. Further investigations on the catalytic systems are required in order to advance the field, particularly to enhance the added value of fuels and to minimize the use of energy. This review aims to provide both the highlights of the remarkable achievements of this field and the milestones that need to be achieved in the future. [ABSTRACT FROM AUTHOR]

Abstract: Zein is a prolamine protein found in corn and has good potential in the development of industrial bioplastics. In this work, zein was modified with several isocyanates and diisocyanates in solution to evaluate its potential usage in bioplastics. The major reaction pathways were identified with the help of NMR and FTIR. For all the isocyanates employed, the surface free energy of the modified zein decreased, which phenomenon indicates decreased hydrophilicity. The moisture uptake decreased with isocyanate and diisocyanate modifications. Gel electrophoretic patterns showed that diisocyanate cross-linked a portion of zein to generate higher molecular weight species. DSC data showed single glass transition temperatures in all cases indicative that homogeneous blends were formed. The mechanical properties of modified zein were either similar to unmodified zein or reduced in some cases. Based on results from NMR and FTIR findings a reaction scheme is proposed. Our findings suggest that the reaction of zein with diisocyanates has potential usage in bioplastics formulations. [Copyright &y& Elsevier]

Abstract: Several modified cottonseed protein isolates were studied and compared to corresponding soy protein isolates for their adhesive properties when bonded to wood composites. Modifications included treatments with alkali, guanidine hydrochloride, sodium dodecyl sulfate (SDS), and urea. Wood composites bonded with cottonseed protein exhibited higher shear strength relative to modified or unmodified soy proteins. Cottonseed protein with SDS treatment gave comparable or better shear strength than unmodified cottonseed protein. Wood composites bonded with unmodified or SDS-modified cottonseed protein also showed superior retained strengths on a hot water test. Thus, a cottonseed protein adhesive (with or without SDS modification) seems to be a viable alternative to soy protein adhesives for wood composites. [Copyright &y& Elsevier]

Abstract: Polymeric composites based on cotton burr and cottonseed bull have been prepared by melt blending and extrusion. For poly(lactic acid) (PLA) and low-density polyethylene (LDPE), addition of the fillers slightly changed the composite''s thermal properties but significantly decreased the composite''s mechanical properties. Heat treatment prior to extrusion resulted in composites with better tensile strength and Young''s modulus. The use of maleic anhydride and peroxide only slightly improved the physical properties of the LDPE materials, but the effect was less clear for the PLA materials. The PLA-filler composites may be useful for lowering the cost of the materials in applications that can tolerate the decreased properties. In addition, the addition of fillers to LDPE might be beneficial in applications to improve stiffness or to improve biodegradability. [Copyright &y& Elsevier]

Abstract: Cotton byproducts, such as cotton burr and cottonseed hull, can be used as low-cost feedstock for the production of specialty chemicals. The conversion of these cellulosic byproducts into mixed cellulose esters, e.g., cellulose acetate propionate (CAP) and cellulose acetate butyrate (CAB), was studied. Instead of using the conventional process for preparing these materials, which uses the appropriate anhydrides, sulfuric or perchloric acid, and methylene chloride as solvent, an iodine-promoted process was used that requires no chlorinated solvent in the reaction mixture. Product ester ratios and degrees of substitution were determined by 1H NMR spectroscopy. At the conditions studied, acetic anhydride was only slightly more reactive than propionic anhydride in the formation of CAP, but acetic anhydride was noticeably more reactive than butyric anhydride in the formation of CAB. [Copyright &y& Elsevier]

Abstract: The processing of cotton generates a number of byproducts, two of which are cotton burr and cottonseed hull. A proximate analysis indicates that they contain about 30–32% cellulose, 17–19% lignin and lesser amounts of protein and oil. They differ in level of hemicellulose with burr containing ∼6% and hull containing ∼20%. Both materials can swell in aqueous NaOH–isopropanol solutions in which state they become susceptible to reaction with monochloroacetic acid. The products of this reaction consist of a water-soluble fraction (observed weight yields ranging from 28% to 55%) and a water-insoluble residue. The water-soluble fractions produce clear films that dissolve slowly in water with viscosities that are somewhat lower than for carboxymethyl products generated from purified cellulose. The products were characterized by NMR and IR and were found to consist mostly of carboxymethyl derivatives of cellulose and hemicellulose. [Copyright &y& Elsevier]

Abstract: A large number of solid-state NMR and ESR experiments were explored as potential tools to study chemical structure, mobility, and pore volume of activated carbon. We used a model system where pecan shells were activated with phosphoric acid, and carbonized at 450°C for 4h with varying amounts of air flow. Through the use of different NMR experiments (e.g., CP-MAS, SPE-MAS, and DD-MAS) several structural parameters were calculated such as mole fraction of bridgehead aromatic carbons, number of carbons per aromatic ring system, and number of phenolic carbons per aromatic ring system. The relaxation time measurements (T 1, T CH, and ) were indicative of the relative mobility of different structural units. ESR spectra showed the presence of π-type aromatic free radicals in the carbonized samples with a slight shift in g value with increasing oxidation. The combined NMR and ESR data give a consistent picture of the carbon structure and the carbonization process, which is not easily available otherwise. In addition, the 1H NMR data on adsorbed water are shown to be consistent with the trends in the amount of pore volumes for different samples of activated carbons. [Copyright &y& Elsevier]

Abstract: Cotton burr and cottonseed hull are relatively inexpensive cotton byproducts. In an effort to derive greater value out of these natural renewable materials, we have succeeded in converting part of them into cellulose acetate without prior chemical breakdown or physical separation of cellulose, lignin, protein, and other components. The conventional approach of treating the raw materials with acetic acid, acetic anhydride, and sulfuric acid in a solvent yielded very little product. An alternative process that involved treating the materials with acetic anhydride and iodine proved to be more successful. No solvent was used in this alternative approach except during the sample workup. The process was optimized by varying the temperature and the amounts of acetic anhydride and iodine used. The best yields obtained thus far were about 15–24%, which corresponded to conversion of between 50% and 80% of the starting cellulose. Formation of the acetates and the degree of substitution were monitored via NMR spectroscopy. [Copyright &y& Elsevier]

Abstract: Phenolic phytochemicals are associated with many health benefits, and it would be useful to develop improved methods for their extraction from bean. In this work, we showed that microwave-assisted extraction was an effective method. Eight bean types important in the Northarvest region of North America, which includes North Dakota and Minnesota, were chosen for this study. Four temperatures (25, 50, 100 and 150°C) and three solvents (water, 50% ethanol in water and 100% ethanol) were investigated. As expected, colored beans contained higher concentrations of extractable phenolics, and in most cases the concentration of phenolics was much higher in the hull (testa) than in the cotyledon. Extraction efficiency was superior at higher extraction temperatures. The most effective extraction was achieved at a temperature of 150°C using 50% ethanol. Total phenolics contents determined by microwave-assisted extraction with water at 100°C were two to three times those determined by conventional extraction with water at the same temperature. [Copyright &y& Elsevier]

Abstract: A new derivative of β-cyclodextrin (CD) has been made incorporating the phenyl group through the use of click reaction. The resulting product suggests a self-association phenomenon through the formation of inclusion compound between the phenyl group and CD. The product has been characterized by 1H and 13C NMR spectroscopy. [Copyright &y& Elsevier]

Polyhydroxyalkanoates (PHAs) are considered promising "green" alternatives to synthetic polymers because they are bio-derived, biodegradable and biocompatible. The properties of bacterial PHA copolymers depend on their microstructures, which can be modified with the use of different fermentation processes and feed materials. Thus, it is desirable to have an improved testing method for the determination of PHA microstructures. In this work, a detailed NMR analysis of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) microstructure was made. Previously only two of the hydroxyvalerate 13C NMR peaks have been assigned at the triad level. In this work, three of the 13C hydroxyvalerate peaks and two of the hydroxybutyrate peaks were found to be split into four peaks each due to comonomer sequence effects. Using eight copolymer samples with a wide compositional range, we were able to assign all these peaks to B-centered and V-centered triad sequences. Through curve deconvolution, the triad intensities were determined. These triad sequence intensities can then be analyzed via both the first-order Markovian and two-component Bernoullian models to obtain more in-depth information on copolymer composition and comonomer reactivities. • A detailed microstructural analysis of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) was made with solution NMR. • New 13C spectral assignments at the triad level for this copolymer were made. • Quantitative 13C NMR sequence data on eight copolymer samples were obtained through curve deconvolution. • The data were fitted to both one-component and two-component statistical models. • This improved NMR methodology should be useful in differentiating samples made with different processes. [ABSTRACT FROM AUTHOR]

To expand the use of cottonseed protein in animal feeding, cottonseed meal was extracted with acetone- and ethanol-based solutions to remove gossypol. Phosphoric acid and water were included in the solutions to catalyze the hydrolysis of protein-bound gossypol. Both solvents were effective at reducing the total gossypol level in meal to between 5% and 10% of its initial value. Gossypol extraction occurred much faster in the ethanol-based extractions than it did in the acetone-based extractions. Treated meals tended to retain phosphorus but most of this could be removed by conducting a final water wash. Water washing also removed hydrophilic components resulting in reduced product yields but increased protein levels. Other acids, e.g., oxalic, citric, or sulfuric acid, were also effective at reducing meal gossypol. In contrast, extractions conducted without acid were not effective. The process can be used to produce low-gossypol cottonseed meals that should be useful in a broader range of feed applications. [ABSTRACT FROM AUTHOR]

Abstract: The reaction of starch and alkyl or alkenyl ketene dimer and starch gave a novel type of hydrophobically modified starch. The reaction was facilitated with the use of an enzyme, which gave products with higher degrees of substitution (DS) at lower temperatures. The starch used included maltodextrin, amylose, cationic starch, and pre-gelatinised starch, with molecular weights ranging from several hundreds to several millions. The DS of the products could be controlled by varying the reaction conditions, such as the amount of enzyme used, the reaction temperature, the concentration of the reactants, and the reaction solvent. This hydrophobically modified starch had improved properties as compared to the original starch and may be used as a thickener or an emulsifier. [Copyright &y& Elsevier]

The interest in the modification of cellulose nanocrystals (CNCs) lies in the potential to homogenously disperse CNCs in hydrophobic polymer matrices and to promote interfacial adhesion. In this work, poly(methyl methacrylate) (PMMA) and poly(butyl acrylate) (PBA) were grafted onto CNCs, thereby imparting their hydrophobic traits. The successful grafting modification led to the increased thermal stability of modified CNCs (MCNCs), and the hydrophobic surface modification was integrated with crystalline structure and morphology of CNCs. The nanocomposites with 7 wt% MCNCs/PBA-co-PMMA had an increase in Young's modulus of >25-fold and in tensile strength at about 3 times compared to these of neat PBA-co-PMMA copolymer. In addition, a micro-phase separated morphology (PBA soft domains, and PMMA and CNC hard domains) of MCNCs/PBA-co-PMMA nanocomposites was observed. The large increase in the storage moduli (glass transition temperatures) and organized morphology of MCNCs/PBA-co-PMMA nanocomposites also elucidated the relationship between mechanical properties and micro-phase separated morphology. Therefore, the MCNCs are effective reinforcing agents for the PBA-co-PMMA thermoplastic elastomers, opening up opportunities for their wide-spread applications in polymer composites. Unlabelled Image [ABSTRACT FROM AUTHOR]

The focus of this work was on the significant changes in the water dynamics of aqueous poly (N-isopropylacrylamide) (PNIPAM) solution during sol-to-gel transition. Through the use of NMR (particularly two-dimensional 2 H NMR T 1 -T 2 relaxation) and rheology, we were able to show that below 34° C fast exchange occurs among free water and water molecules adsorbed on the surface of PNIPAM molecules. At 34° C, PNIPAM becomes aggregated; most of the water molecules are trapped in the PNIPAM aggregates, where water molecules with different dynamics are found. Above 34° C, PNIPAM molecules aggregate further to form a gel network; the free bulk water then becomes dominant at this stage. On the basis of these observations, a model where water molecules interact with PNIPAM in different ways during the transition was proposed. We believe that our experimental approach provides new information and fresh perspectives on the sol-to-gel transition of PNIPAM. [ABSTRACT FROM AUTHOR]

The present work describes the isolation of cellulose nanoparticles (CNs) with different morphologies and their influence on rheological properties of CN and CN-poly (vinyl alcohol) (PVA) suspensions. Cottonseed hulls were used for the first time to extract three types of CNs, including fibrous cellulose nanofibers, rod-like cellulose nanocrystals and spherical cellulose nanoparticles through mechanical and chemical methods. Rheology results showed that the rheological behavior of the CN suspensions was strongly dependent on CN concentration and particle morphology. For PVA/CN systems, concentration of PVA/CN suspension, morphology of CNs, and weight ratio of CN to PVA were three main factors that influenced their rheology behaviors. This research reveals the importance of CN morphology and composition concentration on the rheological properties of PVA/CN, providing new insight in preparing high performance hydrogels, fibers and films base on PVA/CN suspension systems. [ABSTRACT FROM AUTHOR]

Polymer films made from cellulose esters are useful for embedding plant essential oils, either for food packaging or air freshener applications. Studies and testing were done on the physical and mechanical properties of cellulose ester-based films incorporating essential oils (EO) from lemongrass ( Cybopogon citratus ), rosemary pepper ( Lippia sidoides ) and basil ( Ocimum gratissimum ) at concentrations of 10 and 20% (v/w). Results obtained showed that, in all films, the addition of the essential oil caused a decrease in the water vapor permeability due to the hydrophobic nature of the oil. The use of 20% of EO caused lower transparency of the films, although the change was not observed visually. Mechanical testing was done on cellulose acetate, cellulose acetate propionate and cellulose acetate butyrate. It was found that incorporation of lemongrass, basil and rosemary pepper EO significantly affected the Young's modulus, tensile strength and elongation at break of the cellulose ester films. The results suggested that the essential oils interacted with the polymers like plasticizers. The results were confirmed with thermal and microscopic studies. [ABSTRACT FROM AUTHOR]

Cyclodextrin (CD) has often been incorporated into polyurethanes in order to facilitate its use in encapsulation or removal of organic species for various applications. In this work a microwave-assisted method has been developed to produce polyurethanes consisting of α-, β-, and γ-CD and three common diisocyanates. As compared to conventional heating, this new synthetic method saves energy, significantly reduces reaction time, and gets similar or improved yield. The reaction products have been fully characterized with 13 C, 1 H, and two-dimensional NMR spectroscopy. With suitable stoichiometry of starting CD and diisocyanate, the resulting CD polyurethane is organic-soluble and water-insoluble and is shown to remove Nile red dye and phenol from water. Possible applications include the removal of undesirable materials from process streams, toxic compounds from the environment, and encapsulation of color or fragrance molecules. [ABSTRACT FROM AUTHOR]

Abstract: Alkyl celluloses are commercial products that are made typically in an alcohol medium over the course of several hours. In this work an alternative, simplified synthesis of alkyl cellulose is reported, using microwave irradiation and aqueous alkaline medium. No alcohol is needed during the reaction. Reaction time is less than 30min. Conversion varies from 54 to 87%. The degree of substitution varied from 0.2 to 1.0. The production of methyl cellulose and ethyl cellulose was confirmed by 13C NMR and FTIR analysis. [Copyright &y& Elsevier]

Abstract: Agricultural residues are attractive raw materials for the production of industrial polymers because they are renewable and biodegradable, involve less toxic materials during manufacturing, add value to agricultural by-products, and decrease the global dependence on petroleum-based feedstock. In this work, it has been shown that agricultural residues such as wheat straw, barley straw, and rice hull can be converted to methyl cellulose, an industrial polymer used as adhesives, protective coatings, personal care, and in agriculture. Weight yields range from 30 to 70%. The degree of substitution (DS) varies from 0.8 to 2.8. In addition, the methyl cellulose can be further converted to acetylated methyl cellulose. These products have been characterized via NMR analysis. [Copyright &y& Elsevier]

Abstract: Starch is often modified to improve its end-use properties. In this work, we sought to improve the properties of starch through non-covalent means, viz., the blending of starch with poly(acrylic acid), poly(N-vinyl pyrrolidone), and poly(N-vinyl pyrrolidone)-iodine. An emphasis was placed on the rheological and gel forming properties. Starch was found to form a synergistic mixture with poly(acrylic acid). It has no effect on poly(vinyl pyrrolidone) but produces a gel with poly(vinyl pyrrolidone)-iodine. The addition of a small amount of a third polymer caused either increased viscosity (at low addition levels) or gel formation (at higher levels). Through gel formation, a large quantity of starch can be incorporated in the interpolymer complex. These observations are rationalized on the basis of specific interactions among the polymers. Several specific compositions of these blends may find applications as thickeners and encapsulating agents. [Copyright &y& Elsevier]

[Display omitted] • Cashew gum microparticles encapsulating β-carotene were produced by electrospraying. • Smooth and spherical microparticles with sizes between 3 and 6 μm were obtained. • 11 % of extractable β-carotene confirmed the efficiency of the encapsulation process. • Cashew gum demonstrated to offer thermoprotection to β-carotene. • Photoprotection for β-carotene was observed for short periods of time. This study focuses on the production and characterization of electrosprayed cashew gum (CG) microparticles that encapsulate β-carotene. CG is an inexpensive, non-toxic polysaccharide obtained from Anacardium occidentale trees. Encapsulation of β-carotene in CG was performed by electrospraying from two emulsion formulations (water : oil ratios 80:20 and 90:10 (v/v)) in which the dispersed phase consisted of β-carotene dissolved in castor oil, and the continuous phase was a CG aqueous solution. Spherical particles with smooth surface and medium size between 3 and 6 μm were obtained. The particles produced from the 90:10 (v/v) emulsion showed a loading capacity of 0.075 ± 0.006 % and a minor amount of extractable β-carotene, 10.75 ± 2.42 %. ATR-FTIR confirmed the absence of interaction between the particles' components. CG demonstrated to offer thermoprotection, and photoprotection for short periods of time. These results make CG a viable candidate to encapsulate bioactive compounds via electrospraying for agricultural, food and pharmaceutical applications. [ABSTRACT FROM AUTHOR]