Characterization of poly(dicyclopentadiene-co-dihydrofuran) polymers and composites: A frontally polymerizable and deconstructable thermoset

The deconstruction of frontally polymerized poly(dicyclopentadiene) (pDCPD) has previously been achieved by the addition of the comonomer 2,3-dihydrofuran (DHF), introducing enol ether linkages which are cleavable via acid hydrolysis. Although the addition of DHF enables deconstruction, the comonomer inhibits the polymerization reaction and decreases the thermomechanical properties compared to pDCPD. To mitigate the inhibition and decrease in glass transition temperature (Tg) with the addition of DHF to DCPD, this thesis investigates the effects of increasing the concentration of the initiator. The effect of monomer formulation on the front speed, front temperature, Tg, storage modulus (E'), and pot-life (gel time) is highlighted. Furthermore, extrusion of thin (~1.5 mm diameter) filaments using direct ink writing (DIW) at different DHF and initiator concentrations, and bed temperature was performed. The cured resin samples were completely deconstructed at various formulation combinations when kept under inert conditions. Composite laminates consisting of poly(dicyclopentadiene-co-dihydrofuran) and Hexcel AS4C carbon fibers with glass transition temperatures over 140 °C, E' over 35 GPa, and fiber volume fraction (vf) > 50% were manufactured using Vacuum Assisted Resin Transfer Molding (VARTM) process, and were deconstructed to reclaim fibers. Reclaimed fibers were reused to make the next generation composite, for up to three successive generations. Contact angle tests, X-ray photoelectron spectroscopy, and dynamic mechanical analysis (DMA) revealed no significant change in the chemical nature of the fiber surface and the thermomechanical properties of the composite with successive deconstruction and reuse cycles.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Aerospace Engineering

Grantor

University of Illinois Urbana-Champaign

Year dc:date

2025

Author dc:creator

• Bagare, Saurabh Vijay

Contributors dc:contributor

• Baur, Jeffery W.
• Moore, Jeffrey S.

• Frontal Polymerization
• Deconstructible Thermosets
• Recyclable Composites
• Dihydrofuran

Statement dc:rights

• Copyright 2025 Saurabh Bagare

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/129354

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F129354