Polymer Engineering Faculty Research

Title

Synthesis, Characterization, and Evaluation of Amine-Terminated Cycloaliphatic Substituted Polysiloxanes

Document Type

Article

Publication Date

Fall 2007

Abstract

Cyclopentyl- and cyclohexyl-substituted polysiloxanes terminated with amino groups were prepared. Initially, the cycloalkene and dichlorosilane were reacted at high pressure (approx. 250 psi) and high temperature (120 °C) to yield the cycloaliphatic dichlorosilane in a two-step process. Both the mono- and disubstituted chlorosilane monomers underwent an oligomerization to produce cyclic oligomers of low molecular weight (≈2 000 g · mol−1). Amine-terminated polysiloxanes were produced via a base-catalyzed ring-opening polymerization of the cyclic oligomers with 1,3-bis(3-aminopropyl)tetramethyldisiloxane to yield low molecular weight polysiloxanes (≈9 000 g · mol−1, amine equivalent weight = ≈4 300 g · equiv.−1). The polysiloxanes were characterized by 1H and 29Si NMR, and Fourier transform-infrared spectroscopy (FT-IR). The amine-terminated polysiloxane was mixed with a cycloaliphatic epoxy-functionalized cycloaliphatic polysiloxane in order to produce crosslinked epoxy–amine films. The mechanical and physical properties of the film were evaluated and afford a glass transition of the material was 29.5 ± 0.7 °C for the cyclopentyl-substituted polysiloxane and 38.6 ± 0.7 °C for the cyclohexyl-substituted polysiloxane. Evaluation of pull-off adhesion indicated that 0.5 MPa of normal force was required to remove the epoxy/amine film from an aluminum substrate.

Volume

23

First Page

208