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The purpose of this work was to explore the possibility of using cotton gin trash (CGT) as an inexpensive and biodegradable filler for poly(vinyl alcohol) (PVOH). CGT was milled and screened to give fine particles, and the particles less than 150 um in size were used together with three PVOH polymers (with 1–20% vinyl acetate levels) to form composites. Up to 60% by weight of CGT could be incorporated into PVOH to form composite films. Relative to PVOH, these PVOH/CGT films showed reduced tensile strength and elongation at break but enhanced Young’s modulus. CGT was chemically modified through acetylation and succinylation; however, no significant improvement in mechanical properties was observed with these modifications, although acetylated CGT did exhibit somewhat improved elongation at break relative to unmodified CGT for the two PVOH polymers with higher vinyl acetate contents. Thus, for PVOH applications that need reduced cost but can tolerate decreased tensile strength and elongation, cotton gin trash can be used as a cost-effective filler.

Xylan is a major type of hemicellulose that has attracted a lot of research and development activities. It is often derivatized in order to improve its properties. In the literature, hydrophobic modification of polymers is often used to produce surfactant-like materials and associative thickeners. In this work, we have derivatized xylan with alkyl ketene dimer (AKD) and two types of alkenyl succinic anhydrides (ASAs). The xylan-AKD derivatives have been made at 90 &deg, C, using dimethyl sulfoxide as solvent and 4-dimethylaminopyridine as promoter. Samples with degrees of substitution (DS) up to 0.006 have been produced. The xylan-ASA derivatives have been synthesized at 120 &deg, C in dimethyl sulfoxide with DS up to 0.105&ndash, 0.135. The structures of these products have been confirmed with NMR and FT-IR. These xylan derivatives increase the structural diversity of xylan and provide additional options for people seeking to use hydrophobically modified polysaccharides in their applications.

New functional foods and beverages can be developed using bioactive compounds present in pequi oil. Complex coacervation is an encapsulation method used for preserving bioactive molecules, especially those that are hydrophobic or sensitive to high temperatures. The objective of this work was to produce and characterize pequi oil microparticles using cashew gum/gelatin matrix (CG/GE) through complex coacervation. Gum Arabic (GA) was also studied in comparison with CG. The coacervation process was performed without pequi oil to determine the ideal proportions of the matrix components, followed by the embedding of the oil inthe microparticles for evaluation. Satisfactory microparticles were produced at pH 4.5 in the weight ratios of CG/GE = 2:1 and GA/GE = 1:3. Pequi oil release was greater in acidic pH, especially at pH 2 for the CG/GE matrix. The encapsulation efficiency for CG/GE and GA/GE was 72.53% (±4.80) and 82.77% (±6.09), respectively . The results showed that the CG/GE combination seemed very promising as anencapsulation matrix, especially for food applications involving pH values higher than 3.

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., This work was supported in part by the U.S. Department of Agriculture, Agricultural Research Service.

Cashew gum (CG) shows promise of being useful as an agro-based raw material for the production of eco-friendly and biodegradable polymers. In this work, we modified this water-soluble polymer with alkenyl succinic anhydride in order to attach a hydrophobic group to it. The modification used two reagents: octenyl succinic anhydride and tetrapropenyl succinic anhydride. Reactions were conducted at 120 &deg, C using dimethyl sulfoxide as a solvent, with conversions better than 88%. Samples with degrees of substitution (DS) between 0.02 and 0.20 were made. The resulting polymers were characterized using 1H NMR, 13C NMR, FTIR, TGA, and GPC. The addition of the hydrophobe decreased the affinity of cashew gum for water absorption. Hydrophobically modified polysaccharides are often used as polymeric emulsifiers, thickeners, and compatibilizers, we anticipate that these new hydrophobically modified CGs may be used for the same applications.

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., The authors would like to thank the Spanish Ministry of Science and Innovation (MICI) through the RTI2018-097249-B-C21 program number and the EU H2020 YPACK (reference number 773872) for funding.

There is increasing interest in agro-based, biodegradable and eco-friendly wood adhesives as partial replacements for petroleum-based adhesives. In this work, we studied the adhesion of cottonseed ...

Because of the current interest in sustainability, environmental stewardship, and green chemistry, there has been a lot of interest in using agro-based raw materials for the design of polymeric materials. One of the promising biorenewable materials is sucrose, which is inexpensive and widely available. In this work we have carried out the synthesis of sucrose–toluene diisocyanate-based polyurethane through microwave-assisted reactions. Comparisons of conventional heat versus microwave reactions have been made. Microwave-assisted synthesis has been found to significantly decrease the reaction time and save energy relative to conventional heat. The sucrose polyurethane has turned out to be a suitable matrix to prepare semi-interpenetrating polymer networks (semi-IPNs) involving a second material. Two examples shown in this work are the semi-IPNs of sucrose polyurethane with polycaprolactone and soybean oil. Characterization of the polymers has been conducted with 13C NMR, FT-IR, size-exclusion chromatograph...

Many copolysaccharides are compositionally heterogeneous, and the composition determined by the usual analytical or spectroscopic methods provides only an average value. For some polysaccharides, the NMR data contain copolymer sequence information, such as diad, triad, and tetrad sequence intensities. In such cases, it is possible to estimate the extent of compositional heterogeneity through NMR. Two general types of methodologies can be used: perturbed Markovian and discrete component approaches. The theoretical bases for these approaches are reviewed in this work, and three examples are shown of the application of these NMR methodologies to copolysaccharides.

The physical properties of poly(lactic acid) (PLA) are influenced by its stereoregularity and stereosequence distribution, and its polymer stereochemistry can be effectively studied by NMR spectroscopy. In previously published NMR studies of PLA tacticity, the NMR data were fitted to pair-addition Bernoullian models. In this work, we prepared several PLA samples with a tin catalyst at different L,L-lactide and D,D-lactide ratios. Upon analysis of the tetrad intensities with the pair-addition Bernoullian model, we found substantial deviations between observed and calculated intensities due to the presence of transesterification and racemization during the polymerization processes. We formulated a two-state (pair-addition Bernoullian and single-addition Bernoullian) model, and it gave a better fit to the observed data. The use of the two-state model provides a quantitative measure of the extent of transesterification and racemization, and potentially yields useful information on the polymerization mechanism.

Green chemistry is a key opportunity in chemistry and chemical engineering today because it can potentially preserve the environment and human health. It entails the choice of natural biodegradable raw materials and solvents, environmentally acceptable processes, and minimal use of non-hazardous chemicals. Previously, deep eutectic solvents (DES) have found many applications in organic, analytical, and polymer chemistry. The recent discovery of natural deep eutectic solvents (NADES), where many plant-abundant primary metabolites have been found to change their state from solid to liquid at certain temperatures when mixed in a proper ratio, should accelerate their use as replacements for common organic solvents that exhibit inherent toxicity and high volatility. In this work, we have reviewed the application of NADES as green, sustainable solvents in processes that involve polymerizations and polymer reactions. It is clear that many applications have already been explored. Undoubtedly more progress will be made in the future, and NADES will become more commonly used in polymer-related processes.

Over-ripe bananas serve as a good source for non-starch polysaccharides (NSP), which can be used as a functional food ingredient and represent an opportunity for waste utilization. However, ripe banana contains a large amount of sugars, which are undesirable and need to be removed. Traditional extraction methods using alcoholic solvents have many drawbacks. This study aims to use natural deep eutectic solvents (NADES) as new and eco-friendly solvents for the extraction of soluble sugars from ripe bananas. Thirty NADES were characterized and screened, and four of them were selected as most appropriate solvents to remove soluble sugars from banana puree with the help of microwave-assisted extraction. The effects of temperature, time, and quantity of water added to NADES were evaluated. In all cases, NADES were shown to be more effective than conventional solvents (water and ethanol). Among the four NADES, malic acid:beta-alanine:water (1:1:3, molar ratio) with 30 g/100 g of water (25 °C, 30 min) was found to be the most effective in the extraction of soluble sugars from banana puree. Thus, NADES can be considered a highly efficient extraction medium for fruits (such as bananas) and can replace conventional extractions using harsher organic solvents like ethanol.

One of the desirable research goals today is to convert agro-based raw materials into low-cost functional polymers. Among the readily available natural raw materials are the fatty acids that can be obtained from the hydrolysis of plant oils or from the paper industry as byproducts. In this work, a novel iron-containing ionomer has been prepared through the reaction of fatty acids with steel dust or iron powder in the presence of carbon dioxide and water. Characterization has been achieved via 1H and 13C NMR, FT-IR, and size exclusion chromatography. The product has been shown to have an ionomeric structure, consisting of oligomers of fatty acid carboxylates (derived from Diels-Alder reaction) coupled with iron(II) and iron(III) ions (from the oxidation of iron). Because the fatty acid oligomers have low molecular weights, the ionomer easily dissolves in a solvent and can be made into different physical forms, such as liquid, solid, film, or foam.

Xylan is a hemicellulose, which is found abundantly in nature. In this work, a novel polyurethane was developed involving xylan and tolylene-2,4-diisocyanate (TDI). Polymer synthesis was achieved through conventional heat or microwave-assisted reaction in dimethyl sulfoxide. Because xylan has multiple OH groups on each polymer chain, the TDI/xylan molar ratio had to be adjusted to produce a soluble polymeric product. The reaction products were characterized by 13C NMR, FTIR, thermogravimetric analysis, and differential scanning calorimetry. The xylan polyurethane was shown to exhibit improved thermal stability over xylan.

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.

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.

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.

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.

There is current interest in reducing the trans fatty acids (TFA) in hydrogenated vegetable oils because consumption of foods high in TFA has been linked to increased serum cholesterol content. In the interest of understanding the TFA levels, hydrogenation was carried out in this work on soybean oil and cottonseed oil at two pressures (2 and 5 bar) and 100 °C using commercially available Ni, Pd, and Pt catalysts. The TFA levels and the fatty acid profiles were analyzed by gas chromatography. The iodine value of interest is ~70 for all-purpose shortening and 95–110 for pourable oil applications. In all cases, higher hydrogen pressures produced lower levels of TFA. In the range of 70–95 iodine values for the hydrogenated products, the Pt catalyst gave the least TFA, followed closely by Ni, and then Pd, for both oils. For all three catalysts at 2- and 5-bar pressures and 70–95 iodine values, cottonseed oil contained noticeably less TFA than soybean oil; this is probably because cottonseed oil contains a lower total amount of olefin-containing fatty acids relative to soybean oil. Approximate kinetic modeling was also done on the hydrogenation data that provided additional confirmation of data consistency.

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.

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.

Cardanol is an alkyl/alkenyl phenolic material obtained from cashew nut shell liquid (CNSL), which is a byproduct of cashew nut processing. In an effort to develop new uses, cardanol was derivatized for the first time with diethyl azodicarboxylate (DEAD) through the ene reaction. The reaction was facile and required only the application of heat without a catalyst. Both conventional heating and microwave heating were shown to be effective; the latter entailed much shorter reaction time and substantial energy savings. The reaction product (a hydrazino-ester derivative of cardanol) was characterized by nuclear magnetic resonance (NMR). The product increased in viscosity with time and may be useful as a viscosifier in oil-based commercial formulations and as a synthon for further organic reactions.

Polysaccharides are used extensively in various industrial applications, such as food, adhesives, coatings, construction, paper, pharmaceuticals, and personal care. Many polysaccharide structures need to be modified in order to improve their end-use properties; this is mostly done through chemical reactions. In the past 20 years many enzyme-catalyzed modifications have been developed to supplement chemical derivatization methods. Typical reactions include enzymatic oxidation, ester formation, amidation, glycosylation, and molecular weight reduction. These reactions are reviewed in this paper, with emphasis placed on the work done by the authors. The polymers covered in this review include cellulosic derivatives, starch, guar, pectin, and poly(ethylene glycol).

Many polysaccharides are allowed for direct food use, where they serve a number of useful functions including dietary fiber, bulking agent, thickener, encapsulant, gelling agent, foam and emulsion stabilizer, protective colloid, emulsifier and suspending agent, adhesive and binder, flocculant, swelling agent, film/coat former, or syneresis inhibitor. Many of these polysaccharides have complex structures or are mixtures with different components. Over the years, NMR has been a premiere technique for characterizing these materials. NMR characterization can help identify the materials in question, quantify the different functional groups present, and detect minor components and impurities. Above all, the high resolution achieved in solution NMR can provide detailed structural information on composition, sequence distribution, substitution pattern, and molecular weights (in some cases) for individual polysaccharides. Concurrent application of other analytical techniques, such as methylation, esterification, f...

We are introducing a versatile computerized approach to model and simulate polymer tacticities using seven single-stage statistical models. The theory behind the models, e.g., Bovey's versus Price's, Bernoullian, 1st or 2nd order Markovian, enantiomeric types, and combinations thereof is explained. One of the models, "E-B gen", which can be used to produce four types of enantiomorphically controlled tacticities, and the pentad distribution for the model "E-M1" are reported here for the first time. The relations of chain-end controlled models to binary copolymerizations are discussed in detail, and equations for the conversion of tacticity based probabilities to reactivity ratios to obtain related n-ad distributions are presented. The models were applied to 20 polymers with exemplary tacticities found in the literature. A related software program ("Polytact") based on Microsoft's Excel has been designed to calculate all relevant characteristics of the polymer tacticity and to present them in graphical form in a user-friendly manner. The program can be used to produce graphs of the triad, pentad and sequence length distributions and a simulation of 50 monomer repeat units in the polymer for each of the seven models. One of the main intended uses of the program is to compare the computed n-ad distributions to those of experimental polymers obtained from NMR spectroscopy and to gain insight into the polymerization mechanisms.

Four common beans (black, kidney, great northern, and pinto) were extracted with hexane and found to contain about 2% triacylglycerols. The fatty acids in these bean oils were mainly linolenic (41.7–46 wt%), linoleic (24.1–33.4 wt%), palmitic (10.7–12.7 wt%) and oleic (5.2–9.5 wt%). Because of the high levels of polyunsaturated fatty acids, the bean oils had iodine values between 174 and 177 g/100 g (compared to 130 g/100 g for soybean oil). Yet, the bean oils exhibited high oxidative stability due to the presence of high amounts of tocopherols (2,670–2,970 ppm). The bean oils had lower pour points (−18 to −11 °C) compared to −9 °C for soybean oil. Among the four bean oils, kidney bean oil had the highest acid value (15.4 mg KOH/g) and kinematic viscosities over a wide range of temperatures.

An environmentally friendly water-based pathway to form the azide derivatives of soybean oil and fatty esters is reported. This entails first the formation of epoxides and then the azidization of the epoxides. The azidization reaction is carried out at high yields in water with only a small amount of an ionic liquid as a catalyst. The distribution of azide and alcohol functionalities on the fatty acid moiety is approximately random. This reaction has been applied to methyl oleate, methyl linoleate, soybean oil, and methyl soyate. The resulting structures have been studied by NMR.

Starch is often modified to improve its end-use properties. In this work, we sought to improve the properties of starch through noncovalent 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.

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.

Pectins are a class of heterogeneous polysaccharides used in the food industry as a result of their ability to form gels. They are primarily composed of a (1→4)-α-D-galactopyranosyluronic acid backbone where the carboxylic acid group is methyl esterified at a level which depends on the source of the pectin and processing conditions used to isolate the material. Of considerable interest is the distribution of the free acid and methyl ester groups along this polymer chain. NMR spectroscopy, coupled with statistical analysis, is a powerful technique for the study of sequence distribution of monomers. Experimental conditions (temperature, pD) are reported which are appropriate for the analysis of pectic polysaccharides. Results are presented from a study of sequence distribution in native, modified, and fractionated pectins using 1 H and 13 C solution NMR methods. The triad sequence information was examined using Bernoullian and Markovian probability models in conjunction with continuous Gaussian distribution and discrete models. Intermolecular heterogeneity in pectins results in triad frequencies which reflect the distribution of acid and ester monomers for native and base saponified pectins. Fractionation of pectin through physicochemical methods and subsequent spectroscopic analysis provide insight into this heterogeneity. Segregation into discrete polymer populations shows a structural diversity best approximated by a 3-component statistical model.

Partly as a result of the high solution viscosity of bacterial cellulose, carboxymethylcellulose (CMC) derived from this material exhibits shear-thinning and thixotropic properties. With suitable sample treatment, the CMC solution shows gel-like rheology suggesting the presence of a three-dimensional network. This behavior is consistent with heterogeneous substitution of the carboxymethyl functionality on the polymer chains. For comparison, bacterial cellulose is also degraded by either acid or ultrasound to reduce its molecular weight and converted to CMC. The flow behavior of the resulting CMC solutions is nearly Newtonian with slight shear thinning but no thixotropy, suggesting that the carboxymethylation reaction is almost random.

β-galactosidases from A. oryzae and a thermophilic CLONEZYME™ glycosidase library were used to catalyze the transfer of the β- d -galactopyranosyl moiety from lactose to the hydroxyl groups of hydroxyethylcellulose (HEC) in sodium acetate buffer. The degree of substitution was quantified by using galactose oxidase enzymatic assays. Depolymerization was also observed in the course of the transglycosylation reactions.

The Pt-catalyzed hydrosilation reaction between methyl-substituted cyclosiloxane and a nonconjugated diene system produces silicone-carbon polymers with good mechanical and dielectric properties. In this work a statistical model is devised that provides a theoretical description of the polymerization reaction up to the B stage. An ensemble of cyclosiloxane molecules is built up in a computer and allowed to react with the diene (or mixture of dienes) in a Monte Carlo process. Included in the model are options for batch or semibatch operations. Through computer simulation, the concentrations of all molecular species at different conversions (as measured by the residual Si-H group) can be predicted as well as the molecular weight distribution. Good agreement is obtained with observed analytical data. The model is flexible and is used to study the effects of the changes in reaction process conditions on polymer structures and molecular weights.

Eleven catalysts based on Ni, Pd, and Pt from two manufacturers were used for hydrogenating cottonseed oil, with the goal of minimizing trans fatty acid (TFA) content. Despite different temperatures, catalyst levels, and reaction times being used, the data from each catalyst type fell on the same curve when the TFA level was plotted against the iodine value (IV). Under low-pressure, high-mixing hydrogenation conditions, the Ni, Pd, and Pt catalysts all produced < 5% TFA and < 5% stearic acid at 95 IV; however, at 70 IV, only Pt catalysts produced 9% TFA and about 17% stearic acid. Kinetic modeling provided a better understanding of the relative reaction rates involved in hydrogenation. Pt catalysts converted linoleic and oleic acids more slowly to TFA and quickly hydrogenate TFA, thereby leading to low TFA levels. In comparison to other hydrogenated oils reported in the literature, equivalent or lower TFA and stearic acid levels were observed with hydrogenated cottonseed oil under the experimental conditions used.

In many homopolymers the tacticity may be compositionally or sequentially heterogeneous. A computer simulation approach has been developed to simulate tacticity sequence and tacticity distribution for polymers made under a variety of conditions. Included in the simulation are the effects of molecular weight, consecutive and concurrent propagation models, and multiple catalyst/initiator states. In addition, heterogeneity brought about by the fluctuations in the reaction process conditions can also be incorporated. The effect of sequential heterogeneity can be separately visualized through the use of sequence index. Simulations have been made of the tacticity of poly(methyl methacrylate), poly(isopropenylpyridine), and polypropylene

Namesofproductsarenecessarytoreportfactuallyonavailabledata;however,theUSDAneitherguaranteesnorwarrantsthestandardsoftheproducts,andtheuseofthenameUSDAimpliesnoapprovaloftheproductstotheexclusionofothersthatmayalsobesuitable.Thisoverviewbrieflysurveysthepracticeofgreenchemistryinpolymerscience.Eightrelatedthemescanbediscernedfromthecurrentresearchactivities:1)biocatalysis,2)bio-basedbuildingblocks and agricultural products, 3) degradable polymers,4) recycling of polymer products and catalysts, 5) energygenerationorminimizationduringuse, 6)optimalmoleculardesign and activity, 7) benign solvents, and 8) improvedsynthesis to achieve atom economy, reaction efficiency, andreducedtoxicity.Alloftheseareasareexperiencinganincreasein research activity with the development of new tools andtechnologies. Examplesaregivenofrecentdevelopmentsingreen chemistry with a focus on biocatalysis and biobasedmaterials.©2010AmericanChemicalSociety

A family of computer programs (called PODIS) has been written that permits compositional heterogeneity in copolymers to be directly computed. Different sources of compositional heterogeneity have been specifically addressed by separate programs. Included in the treatments are statistical heterogeneity, conversion heterogeneity, multistate heterogeneity, and compositional heterogeneity due to fluctuations in polymerization process parameters. Through these means, predicted chemical composition distributions have been made for linear low-density polyethylene, styrene/ethyl methacrylate copolymers, and styrene/methyl acrylate copolymers

1. Polymer Biocatalysis and Biomaterials - Current Trends and Developments NOVEL BIO-RELATED MATERIALS 2. Chemically Reactive Peptides for the Production of Electroactive Conjugates of Specified Conformation and Side-chain Placement 3. Elastin-Based Protein Polymers 4. Bioartificial Polymer Matrices as Biomaterials with Enzymatically Controlled Functional Properties 5. Enzymatic Products from Modified Soybean Oil Containing Hydrazino-ester 6. Reinforcement Effect of Soy Protein and Carbohydrates in Polymer Composites ENZYME IMMOBILIZATION AND ASSEMBLY 7. Green Oxidation of Steroids in Nano-Reactors Assembled from Laccase and Linear-Dendritic Copolymers 8. Lipase Immobilization on Ultra-fine Poly(acrylic acid)/Poly(vinyl alcohol) Hydrogel Fibers 9. Immobilized Porcine Pancreas Lipase for Polymer Synthesis 10. Effects of Porous Polyacrylic Resin Parameters on Candida antarctica Lipase B Adsorption, Distribution and Polyester Synthesis Activity 11. Immobilization of Candida antarctica Lipase B on Porous Polystyrene Resins: Protein Distribution and Activity NEW SYNTHETIC APPROACHES 12. Bio-catalysis on Surfaces: A Micro-Review aahapatr 13. Design and Synthesis of Biorelated Polymers by Combinatorial Bioengineering 14. Chemoenzymatic Synthesis of Block Copolymers 15. Ring-Opening of ?-Substituted Lactones by Novozym 435: Selectivity Issues and Application to Iterative Tandem Catalysis POLYESTERS AND POLYAMIDES 16. Enzymatic Degradation of Diol-Diacid Type Polyesters into Cyclic Oligomers and its Application for the Selective Chemical Recycling of PLLA-Based Polymer Blends 17. Cutinase: A Powerful Biocatalyst for Polyester Synthesis by Polycondensation of Diols and Diacids and ROP of Lactones DIACIDS AND ROP OF LACTONES 18. "Sweet Polyesters": Lipase-Catalyzed Condensation-Polymerizations of Alditols 19. Candida antarctica Lipase B Catalyzed Synthesis of Poly(butylene succinate): Shorter Chain Building Blocks also Work 20. Enzyme-Catalyzed Oligopeptide Synthesis: Rapid Regioselective Oligomerization of l-Glutamic Acid Diethyl Ester Catalyzed by Papain 21. Enzyme-Catalyzed Polyamides and their Derivatives POLYSACCHARIDES, GLYCOPOLYMERS, AND SUGARS 22. Synthesis of Unnatural Hybrid Polysaccharides via Enzymatic Polymerization 23. Glycopolymers: the Future Anti-Adhesion Drugs 24. Novel Materials Based on Enzymatically Synthesized Amylose and Amylopectin 25. Sugar Based Polymers: Overviews and Recent Advances of Vinyl Sugars Materials 26. Synthetic Peptides Derived from Diatom Cylindrotheca fusiformis: Kinetics of Silica Formation and Morphological Characterisation 27. Enzymatic Dihydroxylation of Arylsilanes

Biocatalysis in Polymer Science provides current information on biocatalysis, which is the use of enzymes or living organisms to carry out chemical reactions. All of the authors, including the editors, are experts and practitionsers of polymer biocatalysis. Topics covered in this book include synthetic polymers, natural polymers, oligomers, an monomers. These topics amply demonstrate the versatility of this technology. Organic chemists, polymer chemists, biochemists, and graduate this book a useful experience.

[reaction: see text] Galactose oxidase produced a C-6 aldehyde in various terminal-containing galactose hydroxylamines for the simultaneous in situ generation of an A-B type condensation for the construction of unique oxime polymers. Molecular weights of the corresponding polymers were determined to be in the range of 4200-8900 g/mol, respectively. This indicates that approximately 20-25 sugar units were incorporated in these unique polymers.

A review is given of the use of soybean oil as a renewable feedstock to produce a range of different materials that contain nitrogen. In the past, most efforts have been concentrated on converting triglycerides to fatty amines and amides. Indeed, many industrially significant fatty amines and amides are known and widely used. More recently, several research groups have developed novel approaches to functionalize the fatty acid chain structures to produce novel compounds, surfactants, and even polymers that contain nitrogen. Some of the approaches (involving organic and enzymatic reactions) may have industrial relevance. Included in this review are reactions with triglyceride oils, fatty acid esters, and methyl soyate (methyl esters of triglyceride oils).

Syndiotactic polypropylene (sPP) with a …rrrrrmrrrrrmmrrrrr … mixed microstructure is obtained with the iPr[CpFlu]ZrCl2/MAO (MAO = methylaluminoxane; Cp = cyclopentadienyl anion; Flu = fluorenyl anion). The structures of the metallocene and the polymers are in accord with chain migratory insertion being the predominant mechanism of chain growth and with stereochemical control being provided by the alternating handedness of polymerization active, cationic Zr monoalkyls.

A general treatment is devised for the 13C NMR spectral analysis of copolymers involving ethene and propene. The basis of the method is the computerized “synthetic approach” proposed earlier (Anal. Chem.) 56, 2320 (1984) and entails the use of first-order Markovian statistics, Monte Carlo polymer chain generation, spectral prediction, and spectral simulation. By this means, copolymer and homopolymer spectra of increasing complexity are readily simulated. The method is shown to accommodate all structural types (viz. stereosequences, regiosequences, and polymer chain ends) and provides good results for atactic poly(propylene), irregular poly(propylene), isotactic ethene/propene copolymers, ethene/propene rubbers, and ethene/propene oils.

Detailed 13C NMR chemical shift rules are devised for ethylene and propylene polymers and for low-molecular-weight analogs. The rules are additive and account for substituent effects as well as for configurational sequences. The agreement between the observed and the predicted shifts is excellent. A computer program has been written to obtain the predicted shifts quickly and with minimum effort.

A general treatment is developed for the 13C-NMR analysis of polymers which contain several components. Reaction probability models and computer optimization techniques are used to resolve the NMR spectral data into separate components. The use of generalized multistate statistical models is introduced and is found to be very suitable for such systems. The computations are simplified by means of computer programs. The need for, and the relevance of, this approach are illustrated by the tacticity problems in polybutylene and polypropylene where two-state and three-state models are used, and copolymer triad sequence analysis for several olefin and acrylic copolymers where two-state models are needed. Three copolymer examples are given: propylene/butylene, ethylene/propylene, and acrylamide/acrylate.