Bio-Based Carbon Fibers and Thermosetting Resins for Use in DoD Composite Applications

WP-1758

Objective

The Department of Defense (DoD) uses composites for various applications and on many weapons platforms to reduce weight and improve performance. Carbon fiber reinforcement and epoxy resin or vinyl ester resin matrix is among the most popular choice of composite material and has excellent properties. All of these components are petroleum-derived and thus their cost and supply are volatile. The process to produce carbon fiber suffers from three inherent limitations: use of hazardous solvents, creation of voids within the precursor fibers due to the removal of solvent, and production of hydrogen cyanide during the thermal stabilization and carbonization steps. Vinyl ester resins produce styrene hazardous air pollutant emissions.

The overall objective of this project is to use renewable resources derived from plants and other sources to prepare high performance carbon fiber and thermosetting matrix resins with high strength and high thermal resistance. In particular, the fundamental scientific objectives are to (1) develop methods for breaking down, modifying, and processing renewable resources to make epoxy resins, vinyl resins, and carbon fibers and (2) determine structure-property relationships for these novel materials.

Back to Top

Technical Approach

High glass transition temperature (Tg) bio-based resins will be prepared by selecting or preparing cyclic and aromatic derivatives of renewable sources, and bio-based fibers will be prepared from derivatives of lignin. Specifically, lignin will be microbially or chemically broken down into oligomers for making bio-based fibers and also cracked to produce low molecular weight chemicals that can be epoxidized or methacrylated for use in thermosetting resins. Iso-sorbide, 5-hydroxymethylfurfural, and furfural derived from starch, cellulose, and hemicellulose are cyclic in structure and can be simply modified to contain epoxide, methacrylate, maleate, and amine functionality. Chitin will be broken down into cyclic diamine dimers to be used for epoxy hardeners. Nuclear magnetic resonance spectroscopy, Fourier Transform InfraRed spectroscopy (FTIR), and size-exclusion chromatography will be used to characterize the molecular weight, chemical makeup, and functionality of the resulting products. Rheological characterization will be used to identify low viscosity formulations for resins and to identify lignin-based oligomers with sufficient viscosity and extensional hardening characteristics for fiber spinning. Lignin-based oligomers will be oriented and melt spun. Ultraviolet-stabilization will then be performed, followed by carbonization and graphitization. The resulting fibers will be characterized using scanning electron microscopy. In situ FTIR will be used to measure the rate and extent of cure of bio-based resins. Dynamic mechanical analysis will be used to measure Tg, modulus as a function of temperature, and cross-link density, while Instron mechanical testing will be used to measure ultimate mechanical properties of resins, individual fibers, and composites.

Back to Top

Benefits

The use of biological resources to make both carbon fiber and high performance thermosetting resins will help reduce the dependence of military composites on the volatile cost of petroleum, thereby helping to reduce the cost of composite materials for DoD. In addition, the processes used to make these fibers and resins from biological sources should have reduced environmental effects. Furthermore, there is a short supply of carbon fiber. The development of these materials/processes will help increase the supply of these materials, allowing increased use by DoD. Over the long term, this will provide life-cycle benefits through reduced costs for composite materials. (Anticipated Project Completion - 2014)

Back to Top

Points of Contact

Principal Investigator

Dr. John La Scala

U.S. Army Research Laboratory (USARL)

Phone: 410-306-0687

Fax: 410-306-0829

Program Manager

Weapons Systems and Platforms

SERDP and ESTCP

Document Types

  • Fact Sheet - Brief project summary with links to related documents and points of contact.
  • Final Report - Comprehensive report for every completed SERDP and ESTCP project that contains all technical results.
  • Cost & Performance Report - Overview of ESTCP demonstration activities, results, and conclusions, standardized to facilitate implementation decisions.
  • Technical Report - Additional interim reports, laboratory reports, demonstration reports, and technology survey reports.
  • Guidance - Instructional information on technical topics such as protocols and user’s guides.
  • Workshop Report - Summary of workshop discussion and findings.
  • Multimedia - On demand videos, animations, and webcasts highlighting featured initiatives or technologies.
  • Model/Software - Computer programs and applications available for download.
  • Database - Digitally organized collection of data available to search and access.