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

Bagare, Saurabh Vijay

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

Description

Title

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

Author(s)

Bagare, Saurabh Vijay

Issue Date

2025-05-09

Director of Research (if dissertation) or Advisor (if thesis)

• Baur, Jeffery W
• Moore , Jeffrey S

Department of Study

Aerospace Engineering

Discipline

Aerospace Engineering

Degree Granting Institution

University of Illinois Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Frontal Polymerization
• Deconstructible Thermosets
• Recyclable Composites
• Dihydrofuran

Abstract

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.

Graduation Semester

2025-05

Type of Resource

Thesis

Handle URL

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

Copyright and License Information

Copyright 2025 Saurabh Bagare

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