I. Applications of the olefin metathesis reaction. II. Application of carbon-hydrogen bond activation to the surface oxidation of polypropylene and polyethylene

by Coleman, Catherine Grace

Abstract (Summary)
Applications of the olefin metathesis reaction to the areas of conducting polymers and crosslinked systems were investigated. Metathesis of cis-3,4-dichlorocyclobutene and 3-acetoxycyclobutene was studied with the WCl$\sb6$/SnMe$\sb4$ and Re$\sb2$O$\sb7$/SnMe$\sb4$ catalyst systems to produce processable precursors to polyacetylene. Polymerization of cis-3,4-dichlorocyclobutene with both catalysts yielded a black particulate solid which was characterized as a partially chlorinated form of polyacetylene. Metathesis of 3-acetoxycyclobutene with WCl$\sb6$/SnMe$\sb4$ resulted in the formation of a complex between the metal and the acetate functionality. Metathesis of 1,3-cyclooctadiene to produce an alternating copolymer of acetylene and cyclohexene resulted in negligible amounts of free cyclohexene when run above ceiling temperature conditions for cyclohexene, indicating that 1,3-cyclooctadiene had polymerized predominately via a non-metathesis mechanism. syn-Tricyclo ($\sp{2,5}$) octa-3,7-diene (TCOD) was synthesized for use as a metathesis crosslinking agent. Solution studies with the WCl$\sb6$/SnMe$\sb4$ catalyst system showed that TCOD could be homopolyerized and also copolymerized with cyclooctene. NMR analysis of the copolymers indicated cyclobutane crosslink junctions. Copolymerization of TCOD with cyclooctene and norbornene using WCl$\sb6$/EtAlCl$\sb2$ gave solid samples which were characterized by swelling and shear modulus measurements. When compared with samples containing TCOD, the control samples (no TCOD) demonstrated a distinct increase in the degree of swelling and a drop in modulus and higher temperatures. Carbon-hydrogen bond activation chemistry was applied to reactions at polymer surfaces to selectively place hydroxyl groups on hydrocarbon polymer surfaces. Four reagents were studied: stannous chloride/oxygen, meta-chloroperbenzoic acid, methanol/benzoylperoxide and trifluoroperacetic acid (TFPAA). Reacted surfaces were analyzed using XPS, ATR-IR, UV, contact angle and gravimetric analysis. The decrease in both the advancing and receding contact angles for the products of each of these reactions indicated an increase in surface energy, and XPS results showed that oxygen had been incorporated onto the surfaces. Kinetics of the TFPAA reaction were studied over a 24 hour period. The reaction proceeded deeply and rapidly($>$1$\mu$m/15 min) to produce a modified surface of hydroxyl and trifluoracetate groups as well as some ketones and non-halogenated ester groups. Base catalyzed hydrolysis, reduction with borane/THF and labeling studies with heptafluorobutyrlchloride showed that the surface-bound functional groups which result from the TFPAA oxidation of polypropylene and polyethylene can act as useful reactive handles for further modification.
Bibliographical Information:


School:University of Massachusetts Amherst

School Location:USA - Massachusetts

Source Type:Master's Thesis



Date of Publication:01/01/1991

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