Poly chemical synthesis

Poly(L-malic acid) denotes a family of polyesters derived from L-malic acid as the building unit. By chemical synthesis, three kinds of poly(L-malic acid) have been obtained, depending on the molecular position of the ester bond the a-type(I) [1], the j8-type(II) [2], and the a,j8-mixed-type(III) [3). 

Fibers in which the basic chemical units have been formed by chemical synthesis, followed by fiber formation, are called synthetic fibers. Examples include nylon, carbon, boron fibers, organic fibers, ceramic fibers, and metallic fibers. Among all commercially available fibers, Kevlar fibers exhibit high strength and modulus. (Kevlar is a DuPont trademark for poly [p-phenylene diamine terephthalamide].) It is an aromatic polyamide (aramid) in which at least 85% of the... 

M. Zagorska and B. Krische, Chemical synthesis and characterization of soluble poly(4,4 -dialkyl-2,2 -bithiophenes), Polymer, 31 1379-1383, 1990. 

The sugar alcohol anhydride polygalitol, 1,5-anhydro-D-glucitol, may be prepared from the root of Poly gala Senega L.49 The process is, however, a time-consuming one and chemical synthesis of the substance by Raney... 

Smith, J.C., Derbyshire, R.B., Cook, E., Viney, J., Brewer, S.J., Sassenfeld, H.M. and Bell, L.D. (1984) Chemical synthesis and cloning of a poly-arg gene fragment designed to aid polypeptide purification. Gene, 32. 321-327. 

The inter-relationship between colloid and polymer chemistries is completed by colloidal polymer particles. The formation of 50-nm-diameter, 100- to 200-nm-long polyaniline fibrils in a poly(acrylic acid)-template-guided polymerization, similar in many ways to those produced from polymerized SUVs (see above), provides a recent example of polymer colloids [449], The use of poly(styenesulfonic acid) as a template yielded globular polyaniline particles which were found to be quite different morphologically from those observed in the regular chemical synthesis of polyaniline [449]. 

Martino, M., and Tamburro, A. M. (2001). Chemical synthesis of cross-linked poly(KGGVG), an elastin-like biopolymer. Biopolymers 59, 29-37. 

It is an axiom of modern organometallic chemistry that the pursuit of late transition metal complexes is ultimately driven by the need to formulate ever more efficient catalysts and reagents for chemical synthesis. In this respect, the field of poly(pyrazolyl)borate chemistry is no different from any other, albeit that in the case of the group 10 triad the breadth of study is perhaps more limited than for other metals and/or ligands. This section provides an overview of prominent results in respect of both catalysis and the C—H activation processes that underpin them. 

Lactic acid, initially produced in 1880, was the first organic acid made industrially by fermentation of a carbohydrate. Nowadays it is made both by fermentation and by chemical synthesis. About 85% of the use of lactic acid is in food and food-related applications, with some use in the making of emulsifying agents and poly(lactic acid). 

The Chemical Synthesis of Oligo- and Poly-ribonucleotides. Reese, C. B. In Nucleic Acids and Molecular Biology Eckstein F, Li He y, D, M. J., Eds. Springer Berlin, 1989 164. 

These early contributions were later supplemented by a comprehensive article on the mononucleotides by Ueda and Fox.4 The present article is an extension of these articles to chemical synthesis of oligo-and poly-nucleotides, and it is hoped that, in conjunction with the earlier articles, it will provide the organic chemist with a reasonable appreciation of some of the challenges, both past and present, of the synthetic chemistry of the nucleic acids. 

Advances in chemical synthesis and in an understanding of the tear film of the eye have resulted in the development of compounds with two or more regions that vary in both their lipophilic nature and binding. The first of these to be tested in the eye was poloxamer 407, a block polymer vehicle with a hydrophobic nucleus of poly-oxypropylene,and hydrophilic end groups of polyoxyethylene. One advantage of poloxamers is their ability to produce an artificial microenvironment in the tear film, which can greatly enhance the bioavailability of lipophilic drugs such as steroids. 

Products 82 are of low chemical stability and rapidly decompose (several minutes) in air decomposition is slower (several days) in the absence of water and oxygen. Thus, these investigations have defined general limitations for poly(arylenemethide) synthesis, set by their chemical instability. A structural analysis of a decomposed ladder-type poly(arylenemethide) 76 has clearly shown that the bridge (methide position) is the site of attack with formation of hydroxyl- or hydroperoxyl-groups [102]. 

The reactions involving the generation of acetylenic bonds or extension of unsaturated bonds are extremely useful in chemical synthesis of unsaturated alcohols, carboxylic acids, and poly-yne acetals [Eq. (47) 125]. For the preparation of essential fatty acids, extension of propargyl units, followed by hydrogenation in the presence of Lindlar catalyst, will result in the efficient formation of ail c/x-type fatty acids [Eqs. (48) and (49) 126,127]. 

Yang, J. Hao, Q. Liu, X. Ba, C. Cao, A. Novel biodegradable aliphatic poly(butylene succinate-co-cyclic carbonate)s with functionalizable carbonate building blocks. 1. Chemical synthesis and their structural and physical characterization. Biomacromolecules 2004, 5 (1), 209-218. 

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