Tomizawa et al 26 provided a mini-review of their work on poly hydroxyalkanoate production by marine bacteria, using sugars, plant oils, and three unsaturated fatty acids as sole carbon sources. Tada et al 27 coupled PEG to antibodies and oligonucleotides through chemical means to solubilized them in organic media. The techniques of PEGylated biopolymers and the methodology for gene PEGylation seem to be promising new tools for the synthesis of designed bio- macromolecular structures.
There is growing interest in biobased materials, partly due to the uncertainly with petroleum-based raw materials and partly due to the increasing appreciation of the limited resources of the world and the need for sustainability.
- Harlan Ellisons Movie.
- Wilfrid Sellars: Naturalism with a Normative Turn (Key Contemporary Thinkers)?
- Robert T. Mathers - Google Scholar Citations;
- The principles of green chemistry?
Several reviews 48 , 49 , 50 , 51 and books 52 , 53 , 54 , 55 are available on the use of natural renewable materials as raw materials for synthesis and polymerization or as ingredients for commercial products. In this book, 12 articles 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 are primarily involved with biobased raw materials or products. Several of these articles deal with polyesters. Thus, Ishii et al 28 carried out polycondensation reaction on caffeic acid a precursor in the biosynthesis of lignin and measured the thermal properties.
Tsui et al 29 made films and foams of poly 3-hydroxybutyrate-cohydroxyvalerate blended with silk fibroin and studied their properties. Zhang et al 30 monitored the polycondensation reaction of adipic acid and trimethylolpropane using 1 H and 13 C NMR as a function of time. Hablot et al 32 reviewed their work using all parts of soybean as raw materials for conversion to value-added products, including ozonation of oil triglycerides to produce polyols, reactions of proteins to polyurethanes, dimer acids to polyurethanes, and silylation of triglycerides.
Biswas et al 33 summarized their work involving common beans, particularly the extrusion cooking of whole beans as food, use of bean as fillers in polymeric composites, extraction of triglyceride oils and phenolic phytochemicals from beans, and conversion of bean starch to ethanol. Dowd and Hojilla-Evangelista 34 prepared protein isolates from cottonseed meals and characterized the solubility and the functional properties of the protein isolates. Cheng et al 35 hydrogenated triglycerides using Ni, Pt and Pd catalysts and obtained oils with distinct amounts of mono- and di-enes, which could be derivatized to produce specific biobased products.
Chung et al 36 developed new lignin-based graft copolymers via ATRP and click chemistry; these hybrid materials had a lignin center and poly n-butyl acrylate or polystyrene grafts. Fundador et al 37 prepared xylan esters with different alkyl chain lengths C2-C12 and measured the mechanical and crystallization properties of these esters.
Wang and Shi 38 converted modified starches into thermoplastic materials; new high-value products were then made from these materials using plasticizers or appropriate blends. Cheng et al 39 added cotton gin trash as filler in low-density polyethylene; the resulting composites are likely to be useful in applications where reduced cost is desirable and reductions in mechanical properties are acceptable.
Because of ongoing interest in degradability, many degradable polymers have been reported. These can be categorized 56 , 57 into three groups: a synthetic polymers, such as condensation polymers, water-soluble polymers, and addition polymers with pro-oxidants or photosensitizers; b biobased polymers, such as polysaccharides, proteins, lipids, and semi-natural polymers, c polyblends, e. Biobased polymers are beneficial in that many of them are biodegradable, often minimize waste, and mitigate disposal problems. Biocatalysis is also helpful because the ensuing products are potentially biodegradable, and the biocatalysts themselves are usually biodegradable.
It may be noted that almost all the polymers described in this book polyesters, polyamides, polypeptides, polysaccharides, proteins, triglycerides, lignin, PEG are biodegradable or potentially biodegradable.
CNA - 一种由环氧大豆油制备环氧大豆油基多元醇的方法 - Google Patents
Most of the enzymes used are hydrolases e. Whereas polyethylene itself is not degradable, the incorporation of a agri-based filler 33 , 39 is a known tactic to improve the degradability of polyethylene.
Many of the degradable polymers can be potentially recycled. Certainly agricultural raw materials and bio-based building blocks are amenable to enzymatic or microbial breakdown and if economically justifiable can be candidates for recycling. Currently even many plastics e. Recycling is also important for biocatalysts in order to decrease process cost; this is one of the reasons for the use of immobilized enzymes.
CN101830802A - 一种由环氧大豆油制备环氧大豆油基多元醇的方法 - Google Patents
As global demand for energy continues to rise, it is desirable to decrease energy use in industrial processes. Biocatalysis is potentially beneficial in this regard because their use often involves lower reaction temperatures and mild reaction conditions 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , Other examples of energy savings in this book are microwave-assisted reactions 17 , reactive extrusion technique 38 and extrusion cooking An active area of current research is biofuels, and many review articles are available 60 , 61 , 62 , An example of this technology in this book is shown for the conversion of bean starch to ethanol In biochemistry, a good example of molecular design is genetic engineering, which permits modification of protein structure in order to optimize a particular activity.
For example, Kawai et al 20 used random and site-specific mutagenesis to improve activity and thermostability of cutinase. In designing new lactate polymers, Nduko et al 24 modified the bacteria via metabolic engineering. Tada, et al 27 utilized a genetic method to incorporate PEG into a peptide. In a different enzyme design, Gitsov and Simonyan 21 made supramolecular complexes of laccase, which facilitated one-pot copolymerization reactions. In product development, structure-property and structure-activity correlations are often employed as part of synthetic design, and several articles on syntheses in this book implicitly incorporated this tactic e.
A highly desirable goal of green chemistry is to replace organic solvents in chemical reactions with water. Biocatalytic reactions are highly suited for this. In fact, several enzymatic reactions and whole-cell biotransformations in this book were done in water e. An alternative is to carry out the reaction without any solvents, as exemplified by several articles in this book 17 , 18 , 19 , 28 , 31 , Optimization of experimental parameters in synthesis and process improvement during scale-up and commercialization are part of the work that synthetic scientists and polymer engineers do.
The use of biocatalysis can potentially improve processes because enzymatic reactions often involve fewer by-products and less or no toxic chemical reagents. An example is the use of biocatalysts instead of copper in ATRP Hablot et al 32 illustrated an example of process improvement in their effort to ozonize soybean oil to generate polyols. Hunley et al 15 identified the key parameters to control enzymatic ring-opening polymerization of lactone, which aided the design of better reaction conditions and next generation catalysts.
Polymer blends and composites are often produced as part of the strategy towards improved products and processes. From the foregoing discussion, it is clear that green polymer chemistry is very much an active area of research and development. Both biocatalysis and biobased materials hold much promise as platforms for innovative research and product developments 64 , 65 , An impressive array of new structures and new methodologies have been developed.
The key to commercial viability is the cost versus benefit of the polymers in use relative to alternatives. For commodity applications like coatings, adhesives, packaging, and construction, cost is a major constraint, but for biomaterials, pharmaceuticals, and personal care there is more latitude.
In view of the wide range of applications, as exemplified by the articles given in this symposium volume, we expect to see continued vigor and vitality in these fields in the future. Anastas P. American Chemical Society. Google Scholar There is no corresponding record for this reference. A review. Dwindling fossil resources, surging energy demand and global warming stimulate growing demand for renewable polymer products with low carbon footprint. Going well beyond the limited scope of natural polymers, biomass conversion in biorefineries and chem.
In context of biofuel prodn. Dreams and reality of "green polymers" are highlighted. Regardless of their new greenish touch, highly versatile and cost-effective polymers play an essential role in sustainable development. Hillmyer M. The field of polymers derived from non-petrochem. Using annually renewable feedstocks, such as biomass, for the prodn. Fundamental research in the prodn.
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The new materials, concepts, and utilizations that result from these efforts will shape the future of polymers from renewable resources. This issue of Polymer Reviews focuses on the prodn. Enzyme-Based Technologies: Perspectives and Opportunities. Microwave Assisted Biocatalytic Polymerizations.
Biocatalysis for the Preparation of Silicone Containing Copolymers. Biosynthesis of Polyhydroxyalkanoate by a Marine Bacterium Vibrio sp. Direct Fluorination of Poly 3-hydroxybutyrate-co -hydroxyhexanoate. Biobased industrial products from soybean biorefinery. Esterification of Xylan and Its Applicaion. Kumar A. Kalra B.
Chemical Reviews Washington, D. Uyama H. Kimura S. A review with refs. Ezymes discussed included peroxidases, laccases, glycosyltransferases, acyltransferases, glycosidases, lipases, and proteases. These products generally can be recycled, incinerated, or thrown away in landfills which is unfortunately the most economical option for most users. Sustainable polymers are produced from a renewable feedstock, i. One of the most popular of these bio based polymers is polylactic acid or PLA; its starting materials are harvested mainly from corn starch and sugar cane, two crops that are very available world wide.