Fluorine-Containing Poly(aryl ethers)

Incorporation of fluorine into the polymer backbone is known to increase solubility, thermal stability, oxidative resistance and flame resistance while decreasing dielectric constant, water absorption and color. Another moiety often incorporated into polymers to improve thermal stability is the ether linkage. The purpose of this research was to determine the effect of the presence of fluorine on solubility and on thermal, mechanical, and electrical properties of poly(aryl ethers). While the presence of fluorine is known to improve these properties, it is also very expensive; therefore, determination of the best placement of fluorine in the polymer backbone is necessary in order to maximize the above benefits while using a minimum amount of fluorine, thus minimizing costs. One fluorine-containing functional group commonly used is the hexafluoroisopropylidene group. Other groups considered include trifluoromethyl and aryl fluoride. Several polyethers were synthesized using the Williamson synthesis. Diphenols of varied fluorine and ether content were reacted with decafluorobiphenyl to form linear poly(ary! ethers) in yields ranging from 48 to 87%. Soluble polymers were obtained from bisphenol A, bisphenol AF, and 4,4'-biphenol with inherent viscosities of 0.28, 1.01, and 0.44 dL/g, respectively. All the polyethers derived from decafluorobiphenyl exhibited high thermal stabilities (460 to 600 °C) by TGA at the point of 10% weight loss. Polymers that did not contain either a flexibilizing group such as hexafluoroisopropylidene or isopropylidene or several ether linkages were either insoluble or very poorly soluble, but the loss in solubility was accompanied by an increase in thermal stability. Polyethers were also synthesized using the Ullmann ether synthesis. In halide monomers containing bromines and fluorines, only the bromines were activated toward displacement under Ullmann conditions. A polymer synthesized from bisphenol AF and 2,5-dichlorobenzotrifluoride in 45% yield was soluble in polar organic solvents and had an inherent viscosity of 0.24 dL/g. Reaction of bisphenol AF with 1,4-dibromo-2,5-difluorobenzene produced a polymer that decomposed upon heating under vacuum.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Chemistry

Grantor

Southwest Texas State University

Year dc:date.issued

1993

Author dc:creator

• Irvin, Jennifer A.

Advisor dc:contributor.advisor

• Cassidy, Patrick E.

Committee members dc:contributor.committeemember

• Fitch, John W.
• Willms, Charles R.

• polymers
• ethers
• fluorine

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/10877/19748

OAI identifier oai:identifier

oai:digital.library.txst.edu:10877/19748