Skip to content

Materials Science and Engineering Georgia Institute of Technology Materials Science and Engineering

Menu
Close
  • ABOUT
    • CHAIR'S WELCOME
    • WHAT IS MSE?
    • ADVISORY BOARD
    • HISTORY
    • CONTACTS & DIRECTIONS
    • OUTREACH ACTIVITIES
    • STRATEGIC PLAN
    • CAREER OPPORTUNITIES
    • AVAILABLE POSITIONS
  • VALUES
    • DIVERSITY AND INCLUSION
    • CREATING RESISTANCE TO SEXUAL HARASSMENT (CRSH)
  • GRADUATE
    • CURRENT STUDENTS
    • PROSPECTIVE STUDENTS
    • FAQ
    • REQUEST INFO
    • APPLY NOW
    • CERTIFICATES
  • PROSPECTIVE STUDENTS
    • GRADUATE
    • UNDERGRADUATE
  • UNDERGRADUATE
    • ACADEMIC ADVISING
    • CURRICULUM
    • MENTORING PROGRAM
    • MSE MINOR AND CERTIFICATES
    • PROSPECTIVE STUDENTS
    • REQUEST INFO
    • RESEARCH
    • SCHOLARSHIPS
    • STUDENT RESOURCES
    • CHANGE MAJOR
  • PEOPLE
    • ALL
    • FTE FACULTY
    • STAFF
    • ACADEMIC PROFESSIONALS
    • RESEARCH SCIENTISTS/POST DOCS
    • ADJUNCT FACULTY
    • COURTESY APPOINTMENTS
    • EMERITUS FACULTY
    • GRAD STUDENTS
    • ADMINISTRATION
    • STAFF - WHO DOES WHAT
  • GIVING
    • STUDENT SUPPORT
    • SUPPORTING THE MILL
    • SUPPORTING RESEARCH AND FACULTY
    • SUPPORTING THE SCHOOL
    • WHY GIVE NOW
    • WAYS TO GIVE
  • MILL
  • RESEARCH
    • MATERIALS AND CHALLENGES
    • RESEARCH CENTERS
    • INDUSTRY RELATIONS
    • TOPICAL WORKING GROUPS
    • FACULTY RESEARCH OVERVIEW
  • INDUSTRY
  • SAFETY
  • Georgia Tech Home
  • Campus Map
  • Directory
  • Offices
  • Facebook
  • YouTube
Search

Search form

  • You are here:
  • Home

Dissertation Defense – Luc Le

Event Type: 
MSE Grad Presentation
Event Date: 
Tuesday, October 12, 2021 - 10:00am
Talk Title: 
“Development of a High-Performance Reversible Crosslink Epoxy Composite by using Diels Alder Chemistry”
Location: 
Via Bluejeans Video Conferencing https://bluejeans.com/942835183/0498

Committee Members:

Prof. Karl Jacob, Advisor, MSE/ME

Prof. Kyriaki Kalaitzidou, Co-advisor, ME/MSE

Prof. Paul Russo, MSE/CHEM

Prof. Youjiang Wang, MSE

Prof. Anselm Griffin, MSE

 

Abstract:

Thermoset polymers, due to a unique combination of high mechanical strength, thermal stability, and chemical resistance, are widely used by multiple industries for both commercial/industrial and residential applications. Epoxy resins are the most commonly used thermosets as they display high heat resistance, good chemical and corrosion resistance, high tensile strength, high modulus, high adhesion, low percent shrinkage in the cure, and excellent adhesion to various substrates, etc. However, due to the permanent chemically cross-linked structure they are non-recyclable at the end of life and end up in landfills or are incinerated. This challenge can be overcome by creating a dynamic covalent adaptable network (CAN) via reversible chemical reactions to replace the permeant crosslinks.

The goal of this research is to synthesize epoxy resins able to be recycled at the end of life using renewable materials by utilizing the thermally reversible dynamic bonds of the Diels-Alder (DA) reaction between furan and maleimide. In the first objective, the semi bio-based linear furan grafted epoxy prepolymer was synthesized by step-growth polymerization in one pot reaction that enabled control of the prepolymer’s molecular weight using the mono-functional group as the chain stopper. Furthermore, the thermodynamics and kinetics of DA crosslink formation in the epoxy network were investigated by selecting two different electronic structures: aromatic versus aliphatic maleimide to react with furan on the epoxy prepolymer to tune the retro DA temperature. This provided understanding on how the process parameters including curing temperature, dictate the upper temperature for the polymer structure stability as well as the reprocess conditions. The results indicate that the aromatic maleimide has higher kinetics reactivity toward furan in prepolymer and lower retro DA temperature for the adducts than the alkyl maleimide.  The efficacy of the CAN polymer and its thermo-mechanical properties strongly depend on the architecture polymers such as prepolymer chain characteristics, crosslink density and distribution, etc. The second objective was to elucidate the process-structure-property relationship of the CAN system as a function of prepolymer chain length and the crosslinker prepolymer-crosslinker ratio. The higher percentage of furan grafting on the prepolymer backbone results to shorter chain prepolymer and higher DA crosslink density in the polymer network that helps intrinsic self-healing. On the other hand, the network loses its structural integrity at temperatures higher than the glass transition temperature and exhibits poor solvent resistance. A 1:1 stoichiometric ratio of maleimide crosslinker to the prepolymer’s furan from results in more homogeneous crosslink distribution leading to a network where the bonds reverse at higher temperature. The third objective was to investigate the effect of nanocellulose that was modified to have with diene or dienophile characteristic on the mechanical strength and thermal reversibility of DA adduct of the optimized epoxy network. It is concluded that nanocellulose enhanced the mechanical properties of the epoxy network, yet it interferes with the CAN system at the retro DA temperature inhibiting the thermal reversibility of the network. The research provides fundamental understanding on how the crosslinker type and prepolymer length for the CAN system can be selected to fine tune the mechanical, viscoelastic, and reversible response to a thermal trigger enabling greener and recyclable epoxy resins.

ABOUT

  • About
    • Chair's Welcome
    • Strategic Plan
    • What is MSE?
    • Careers
    • History
    • Contacts & Directions
    • Outreach Activities
    • External Advisory Board
    • Events
      • Past Events
    • News
    • Seminars
      • Brumley D Pritchett Lecture Series
      • Industry Executive Seminars
      • Past Seminars
      • Upcoming Seminars

Student Resources

  • Undergraduate Handbook
  • Undergraduate Registration
  • Overload Requests
  • Graduate Handbook
  • Lab Safety Policy
  • Student Mentoring Program

Faculty & Staff Resources

  • Faculty & Staff Directory
  • Administration
  • Institute for Materials
  • Financial Forms

Quick Links

  • College of Engineering
  • COE Ethics Statement
  • Bursar's Office
  • Registrar's Office
  • International Education
  • Financial Aid
  • Student Affairs
  • Tech Lingo
  • Title IX/Sexual Misconduct
Map of Georgia Tech

Georgia Institute of Technology
North Avenue, Atlanta, GA 30332
Phone: 404-894-2000

  • Emergency Information
  • Legal & Privacy Information
  • Accessibility
  • Accountability
  • Accreditation
  • Employment
  • Login
Georgia Tech

© Georgia Institute of Technology