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Bio-olefins prepared by acyclic diene metathesis

Posted on:2004-07-12Degree:Ph.DType:Thesis
University:University of FloridaCandidate:Hopkins, Timothy EdwardFull Text:PDF
GTID:2461390011462805Subject:Chemistry
Abstract/Summary:
The incorporation of amino acids and peptides into polymers can result in materials with desirable properties, such as enhanced solubility, secondary structure formation, biodegradability, and/or biocompatibility. Amino acid/peptides can be incorporated into a polymer via two methodologies. The first entails the incorporation of the amino acid/peptides directly into the backbone of a polymer resulting in a poly(ester amide), which should be biodegradable. The other main method of incorporation is to branch amino acids/peptides off of the polymer backbone, resulting in a polymer with a backbone that is not biodegradable and not soluble resulting in a material with the potential use for biologically active surfaces.; Acyclic diene metathesis (ADMET) has been used to prepare poly(ester amide)s containing an amino alcohol moiety. It was found that the proximity of the functionality to the olefin was important: the polymerization suffers from slow kinetics when the functionality is located three or less carbons from the olefin. In addition, the polymers are semicrystalline, and demonstrate an increased melt upon hydrogenation.; The branched amino acids/peptides can be attached to the diene through either the C or N-terminus yielding monomers with different reactivities. Polymers with an amino acid on every 9 th carbon polymerize when attached through the N-terminus but not through the C-terminus, and this trend is continued for the highly polar arginine branched monomer located at every 21 st carbon. Also, the solvent used played a profound role on the polymerizability, where THF was determined to be the ideal solvent for the polymerization of these highly polar monomers.; In addition, these amino acid/peptide containing polyolefins, termed bio-olefins, have interesting physical properties. Over half of the polymers prepared are semicrystalline with Tms up to 150°C and up to 60% crystallinity as determined by DSC and WAXD, respectively. Initial Instron testing demonstrates that bio-olefins have good material properties, i.e. elasticity and high tensile strength, probably due to the high degree of functionality and hydrogen-bonding ability. Further, surface studies demonstrate that the functionality is located on the surface at 45° and 90° for nonbulky and bulky peptides, respectively.
Keywords/Search Tags:Amino, Bio-olefins, Diene, Polymers, Functionality
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