DOI
https://doi.org/10.25772/8417-DD35
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