Controlled degradation of disulfide-based epoxy thermosets for extreme environments

• Published in: Polymer (Guilford) Vol. 64; pp. 84 - 92
• Main Authors: Johnson, Leah M., Ledet, Eric, Huffman, Nicolas D., Swarner, Stephanie L., Shepherd, Sarah D., Durham, Phillip G., Rothrock, Ginger D.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.05.2015
• Subjects: Degradable polymer; Degradation; Demand; Dissolution; Disulfide; Disulfides; Ethers; Exposure; Polymer blends; Thermoset; Thermosetting resins; Degradable polymer; Disulfide; Thermoset
• ISSN: 0032-3861; 1873-2291
• DOI: 10.1016/j.polymer.2015.03.020

The burgeoning field of smart materials for oil exploration and production (E&P) demands robust polymers that remain stable in extreme conditions, but readily respond to specific chemical cues. Here, disulfide-based epoxy polymers are designed to withstand harsh, simulated oil reservoir conditions while simultaneously retaining the ability to degrade from thiol compounds. Degradable epoxy thermosets are prepared by using Bisphenol-F diglycidyl ether (BFDGE) in combination with blends of p,p′-diaminodicyclohexylmethane (PACM) and 4-aminophenyl disulfide (4APDS). These polymer systems retain their mechanical properties after exposure to extreme conditions (e.g., two weeks, 69 MPa, 100 °C, pH 12), but degrade in the presence of 2-mercaptoethanol (2-ME). Parameters that influence polymer degradation are detailed including temperature, concentration of disulfide groups, and monomer stoichiometry. Formulations that entirely dissolve after exposure to 2-ME are utilized further for release of prototype tracers. Disulfide-based epoxy thermosets provide a unique platform for applications in harsh environments requiring robust materials capable of on-demand degradation. [Display omitted] •Epoxy thermosets are prepared that contain different amounts of disulfide groups.•Degradation is controlled by temperature, disulfide content, and stoichiometry.•Disulfide epoxy polymers withstand conditions of two weeks, 69MPa, 100 °C, pH 12.•Formulations that completely dissolve in 2-mercaptoethanol are described.•Macro-particles comprising disulfide epoxy are used to release prototype tracers.