Creation and modification of polymeric materials using electron beam radiation

This dissertation begins with a review of radiation chemistry and a number of important variables which can influence the chemistry occurring in irradiated polymeric materials. Following the literature review, four different studies involving the electron beam irradiation and subsequent characterization of various polymeric materials are presented. The first study describes a novel process that has been developed for producing crosslinked polymeric microspheres. With this process, it is possible to produce polymeric microspheres in an aqueous media with a solids content as high as 67 vol % by incorporating a trifunctional acrylate into a biliquid foam (known as polyaphrons) and exposing it to electron beam radiation. The second study involves characterizing the radiation response of a relatively new crystallizable polyimide, LARC-CPI, primarily in terms of its thermal properties as determined by differential scanning calorimetry (DSC), with some limited x-ray scattering experiments. The third study illustrates the effects of electron beam radiation on four different glassy polymers that have been physically aged prior to irradiation. It is shown that irradiation reduces the extent of aging present in the material and that this reduction is proportional to the absorbed dose. The last study examines the crosslinking behavior of a polystyrene - poly(vinyl methyl ether) blend as a function of absorbed dose, composition, and phase separation. It is shown that the crosslinking behavior (in terms of the gel fraction produced) is strongly dependent on all three of these factors. Furthermore, the protective nature of the aromatic groups in polystyrene that is typically displayed by this polymer was not observed in this blend system.

Name thesis:degree_name

Ph. D.

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Chemical Engineering

Department dc:contributor.department

Chemical Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1991

Author dc:creator

• McHerron, Dale C.

Chair dc:contributor.committeechair

• Wilkes, Garth L.

Committee members dc:contributor.committeemember

• Cox, David
• Ward, Thomas C.
• Davis, Richey M.
• Wightman, James P.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

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

Language dc:language.iso

en

Dc Identifier Other

etd-10142005-135820

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/39936