Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List


LawYukYu Dissertation.pdf (1.75 MB)

ETD Abstract Container

Abstract Header

Silica Dispersion for Applications in Rubber Processing

Law, Yuk Yu
http://rave.ohiolink.edu/etdc/view?acc_num=case1363116801

Abstract Details

2013, Doctor of Philosophy, Case Western Reserve University, Chemical Engineering.
The use of silica as a reinforcing agent is an important and emergent technological advancement in rubber compounding. The improved performance of silica-reinforced rubber composites is made possible through treatment of the silica by coupling agents (CA) such as bi-functional alkoxysilane molecules. The CA chemically binds to surface silanol groups so that interparticle and particle-polymer interactions are modified in a manner that improves the silica dispersion quality as well as the processability of silica-reinforced rubber composites. However, the control of CA-silica reactions during composite manufacturing processes remains a challenge due to the lack of a fundamental understanding of CA reaction mechanisms and kinetics. In this work, we studied the wetting behavior in beds of silica particles possessing complex microstructures using liquid infiltration analysis. Simultaneous measurement of the rate of liquid mass uptake and the volume occupied by that liquid within the particle bed provides information about the fraction of pore volume that participates in liquid infiltration along with the effective size of the geometric unit that governs infiltration kinetics. This provides the quantitative information for interpreting effects of silica microstructure on liquid infiltration behavior during dispersion. We developed a new thermogravimetric analysis (TGA) technique to study the kinetics of binding of a CA molecule onto silica, and the bound-rubber formation on surface-modified silica. Derivative TGA curves of the CA-functionalized silica show distinct peaks which correspond to the alkoxysilane bound to one or two surface silanol sites. Binding at two silanol sites is postulated to occur in a two-step series reaction model. The bound rubber formation is attributed to be the direct binding of a polymer chain with a number of nonpolar interactive sites provided by the CA molecules on the silica surface. We have demonstrated that the TGA technique is a powerful tool for direct studies of coupling reactions. Moreover, we developed the first model analysis for the torque requirements for the dispersion of silica in the batch mixing of solution styrene-butadiene rubber. We have provided a method for correlating material and processing parameters with silica dispersion behavior, and this model allows predictions of silica dispersion at practical mixing conditions applicable to scale-up process optimization.
Donald Feke, Professor (Advisor)
Ica Manas-Zloczower, Professor (Advisor)
J. Adin Mann, Professor (Committee Member)
Syed Qutubuddin, Professor (Committee Member)
130 p.
Chemical Engineering
Silica; Rubber; Dispersion; Coupling agents; Alkoxysilane

Recommended Citations

Citations

  • Law, Y. Y. (2013). Silica Dispersion for Applications in Rubber Processing [Doctoral dissertation, Case Western Reserve University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=case1363116801

    APA Style (7th edition)

  • Law, Yuk Yu. Silica Dispersion for Applications in Rubber Processing. 2013. Case Western Reserve University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=case1363116801.

    MLA Style (8th edition)

  • Law, Yuk Yu. "Silica Dispersion for Applications in Rubber Processing." Doctoral dissertation, Case Western Reserve University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=case1363116801

    Chicago Manual of Style (17th edition)

case1363116801
2,365
© 2013, all rights reserved.
This open access ETD is published by Case Western Reserve University School of Graduate Studies and OhioLINK.