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Investigations of the silane/epoxy matrix interphase for silane coupling agent blends of varying composition

Tidrick, Shari Lynne.
http://rave.ohiolink.edu/etdc/view?acc_num=case1055857671

Abstract Details

1991, Doctor of Philosophy, Case Western Reserve University, Macromolecular Science.
To study the effects of various silane coupling agent blends on composite properties, cylinders made of a benzyldimethylamine (BDMA)-catalyzed, nadic methyl anhydride (NMA)-cured diglycidyl ether of bisphenol-A (BDGE) were filled with 30 weight % of silica. The silica had been treated by silane blends of either γ-aminpropyltriethoxysilane (APS) and butyltriethoxysilane (BTS) or APS and ethyltriethoxysilane (ETS). A variety of techniques were utilized to compare the effects of BTS versus ETS and the concentration of amine in the silane blend. The results indicate the importance of structure and composition of the silane interphase on the properties of composite materials. The effect of varying composition of nonhydrolyzed silane coupling agent blends of APS and BTS on the cure of the epoxy matrix was studied by Fourier transform infrared spectroscopy (FTIR). The silane blends perturbed the kinetics of the alternating anhydride-epoxy copolymerization reaction, with the perturbation being a nonlinear function of the relative amine concentration in the system. The effect of hydrolyzed and nonhydrolyzed of various compositions of silane coupling agent blends of APS/BTS or APS/ETS on the cure of a BDMA-catalyzed, NMA-cured BDGE were investigated by FTIR. The presence of the amine group perturbs the alternating copolymerization of the anydride and epoxy groups by initiating and catalyzing the reaction. Hydrolysis also promoted the reaction rate. Samples containing ETS cured more rapidly than those containing BTS at the same composition. Imide formation was not significant in the presence of the alkyl-ended silanes. APS/BTS and APS/ETS silane coupling agent blends of varying composition were added to the epoxy matrix. 29Si nuclear magnetic resonance was utilized in order to determine the effect of composition of the silane coupling agent blend on the mobility of the various portions of the siloxane network. Hydrolysis caused an increase in the rigidity of the highly condensed structures, but decreased the rigidity of the silicon atoms bonded to only one or two oxygen atoms. This phase separation could possibly lead to stress concentration within the network structure. Increasing amine concentration caused only slightly increases in rigidity. Although ETS gave consistently lower rigidity values than BTS, these values were not statistically significant. (Abstract shortened with permission of author.)
Jack Koenig (Advisor)
225 p.
Investigations silane/epoxy matrix interphase silane coupling agent blends varying composition.

Recommended Citations

Citations

  • Tidrick, S. L. (1991). Investigations of the silane/epoxy matrix interphase for silane coupling agent blends of varying composition [Doctoral dissertation, Case Western Reserve University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=case1055857671

    APA Style (7th edition)

  • Tidrick, Shari. Investigations of the silane/epoxy matrix interphase for silane coupling agent blends of varying composition. 1991. Case Western Reserve University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=case1055857671.

    MLA Style (8th edition)

  • Tidrick, Shari. "Investigations of the silane/epoxy matrix interphase for silane coupling agent blends of varying composition." Doctoral dissertation, Case Western Reserve University, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=case1055857671

    Chicago Manual of Style (17th edition)

case1055857671
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© 1991, all rights reserved.
This open access ETD is published by Case Western Reserve University School of Graduate Studies and OhioLINK.