Defense Date

2012

Document Type

Dissertation

Degree Name

Doctor of Philosophy

Department

Engineering

First Advisor

Kenneth Wynne

Second Advisor

Mark McHugh

Third Advisor

Gary Bowlin

Fourth Advisor

Gerrard Heck

Fifth Advisor

Thomas Haas

Abstract

Fumed silica filler has long been used to structurally reinforce silicone elastomers. Unfortunately, the combination of as little as a few weight percent of untreated fumed silica nanoparticles [uFSN] with a siloxane polymer, such as PDMS, forms a difficult to process waxy solid admixture that even long periods of high shear mixing will not thin. In the course of the current work it was noted that after a period of storage certain solid admixtures would become viscous liquids when subjected to additional high shear mixing. It was further found that the required aging period could be decreased if the admixture storage temperature were increased. The only known interaction of PDMS and uFSN at moderate conditions is the adsorption of polymer on filler, and this interaction is also known to occur more quickly at higher temperature. This study examines the relationship between polymer adsorption and admixture liquefaction. Further, the mechanical properties of cured elastomers containing liquefied admixtures are examined to assess the degree of reinforcement that these materials afford.

Rights

© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

December 2012

Available for download on Tuesday, December 12, 2017

Included in

Engineering Commons

Share

COinS