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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

The 13C NMR spectra of ethylene oxide/epichlorohydrin copolymers are fully assigned. Information available includes copolymer composition, comonomer sequence distribution, and epichlorohydrin tacticity. The comonomer sequence distribution can be fitted to a two-component (Bernoullian/Bernoullian) statistical model.

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.

13 C NMR and temperature rising elution fractionation result indicates that the ethylene-propylene copolymer made with a heterogeneous titanium-based catalyst contains three or four separate components, each of which approximately obeys Bernoullian statistics. The Bernoullian probabilities vary from 0.03 to 0.60 and reflect the large differences in ethylene/propylene selectivity of different catalytic sites

A mixture of soybean oil with diethyl azodicarboxylate exhibits a remarkable self-curing and thickening behavior at room temperature due to the occurrence of crosslinking ene reactions. The kinetics and the reaction mechanisms have been studied with the help of model compounds, 1H and 13C NMR, and size exclusion chromatography. The reactions are found to be most facile with linolenate, followed by linoleate, and least with oleate. The product from this reaction may be used as an environmentally friendly self-curing agent in appropriate applications.

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.

Obtention d'informations sur la composition du copolymere, la distribution des sequences et la tacticite

Copolymers of ethylene and ethylene-d4 were prepared, and their composition and comonomer sequence distribution determined from high-field 13C NMR spectra. For a conventional Ziegler-Natta catalyst, deuterium was shown to decrease the reactivity of ethylene.

The configuration of vinyl polymers has been conventionally described by either Bovey's or Price's formalism. In this work, the relationships between these two formalisms are derived, and their relevance to polymerization mechanisms is delineated. Experimental data for nuclear magnetic resonance (NMR) pertaining to either chain-end control or catalytic-site control are tested using the computerized “analytical approach.” Suitable polymeric systems are illustrated.

The minor resonances in the 13C NMR spectrum of poly(propylene) prepared with soluble Group 4 metallocene/methylalumoxane catalysts are fully characterized. The 13C shifts for regioirregular sequences, chain-end structures, and 1,3-propylene adduct are obtained for both isotactic and atactic components. In both components the dominating mechanism is 1,2-insertion, with much lower amounts of 2,1-insertion and 1,3-insertion depending on the catalysts used. The isotactic component is stereoregular in all insertion modes. In the atactic components random stereosequences are observed. The regiostructures suggest that the propagation step is catalyticsite controlled even for the atactic component.

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.

The microstructure of polyepichlorohydrin was directly studied by high-field 13C-NMR. Spectral features were found that correspond to different tacticities. By using curve deconvolution techniques, the different tacticities were assigned and quantified.

Poly(1,5-hexadiene) was prepared and its structure characterized by high-field 13C nuclear magnetic resonance. The polymer was shown to contain repeating five-membered rings separated by methylene bridges, with both cis and trans placements present in a 54 : 46 ratio. The result is compatible with the Marvel-Garrison two-step reaction mechanism.

By means of carbon-13 nmr (at 25 MHz) the trans/cis conformer ratio in glycyl-L-proline has been measured in aqueous (D2O) solution over the temperature range 33–96°C. It is found that ΔH0 = −4.2 kJ/mole and ΔS0 = −9.7 J/mole/K. Measurements of the T1 values for the proline ring carbons yielded values consistent with a fast puckering process involving both the β- and γ-carbons. Measurements of the rate of cis-trans conformational interconversion in glycyl-L-proline, using complete line-shape analysis for the glycyl α-carbon resonance, gave values for the trans cis isomerization as follows: ΔH≠ = 83.5 ± 0.2 kJ/mole; ΔS≠ = 0.0 ± 10 J/mole/K. A more approximate determination from coalescence temperature observations gave a value of ΔG≠ of 82.0 ± 0.4 kJ/mole for this process in acetyl-L-proline in aqueous solution. The presence of 12M NaSCN lowered this barrier by ca. 2.6 kJ/mole. Such measurements are relevant to present theoretical models of the denaturation-renaturation processes in proteins, in which proline residues may play a key role.

The existing Ti and Zr metallocene/methylalumoxane (MAO) isospecific propylene polymerization catalyst systems are unsuitable at conventional polymerization temperatures. The most significant problems have been that Ti(IV) complexes are reduced to inactive species (1,2) and that the Zr analogues produce wax (3–7).