Synthesis and characterization of poly(2,2,2- trifluoroethoxyphosphazene)polystyrene graft copolymers

Poly[bis(2,2,2-trifluoroethoxyphosphazene)]-polystyrene graft copolymers were synthesized by a “grafting onto" reaction which involved a reaction between two preformed, reactive polymer chains. In this case, poly(dichlorophosphazene) was the reactive polymer backbone onto which approximately 10 weight percent polystyrene chains were grafted. In order to avoid chain degradation of the poly(dichlorophosphazene), the polystyryl lithium chains were modified by the addition of ethylene oxide. This reaction introduced -CH₂CH₂O⁻Li⁺ groups on the chain ends and rendered them a more suitable nucleophile. Remaining chlorine sites along the poly(dichlorophosphazene) backbone were substituted with 2,2,2-trifluoroethoxy groups. The grafting reaction proceeded with and without the catalyst, tetrabutylammonium bromide. This reagent acted as an ion separation catalyst and seemed to increase the reactivity and ionic character of the O⁻Li⁺ bond. This was evident with respect to reaction times. The catalyst decreased reaction times from several days for the uncatalyzed reaction to ~30 hours for the catalyzed reaction. Difficulties in characterization of the poly[bis(2,2,2-trifluoroethoxyphosphazene)]-polystyrene graft copolymers were encountered. DSC analysis of both the graft copolymer and homopolymer physical blends seemed to indicate partial compatibility between the polystyrene and poly[bis(2,2,2-trifluoroethoxyphosphazene)] components. Infrared and ultraviolet spectroscopy revealed the presence of polystyrene in the graft copolymer system; however, these results were difficult to verify due to the possibility of polystyrene homopolymer contamination. Calculation of the number of polystyrene chains grafted onto the polyphosphazene backbone were hampered by resultant insolubility of the graft copolymer system.

Name thesis:degree_name

M.S.

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Chemistry

Department dc:contributor.department

Chemistry

Grantor dc:publisher

Virginia Polytechnic Institute and State University

Year dc:date.issued

1983

Author dc:creator

• Hernandez, Pamela Bires

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/10919/113496

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/113496