Jacobs, Matt (Brigham Young University)
Faculty Advisor: George, Andy (Engineering, School of Technology); Miles, Mike (Engineering, School of Technology)
Composites are unique materials in many respects. When fabric woven from carbon fibers is joined with a thermoset resin in a controlled environment, it results in a very strong material. One aspect of this construction that provides great strength lies in the crosslinked chains of plastic polymers, which form strong bonds as the resin cures. It's a two-edged sword, though. Although the resin and the composite are quite strong together, they are very difficult to pull apart once they're formed, in order to be able to use again in the future. As such, composite structures formed with industry-standard thermoset resins have a single-use lifespan. The cheapest thing to do to dispose of them is to simply throw them away. However, by isolating the dry fibers by burning off the resin (a process called pyrolysis), the fibers are able to be processed again in useful ways — they are reclaimed. My research focuses on pyrolysis and ways to optimize its process. I aim to showcase its environmentally-friendly capabilities through making new composite structures with fibers reclaimed via pyrolysis to lessen landfill waste.
For the experimental phase of the research, a roll of unprocessed carbon fiber material will be selected for producing 4 test groups:
Virgin-sized carbon fibers
Fibers that have undergone pyrolysis
Fibers infused to part and reclaimed with pyrolysis, oxygen-free environment
Fibers infused to part and reclaimed with pyrolysis, ambient air environment
Fiber samples will then be processes into 3mm length fibers. Fibers will then be introduced to Matrix at TBD% Fiber volume content, following which, dog bones will be molded from samples for tensile testing. Dog bones will then be tensile tested and analyzed at fracture point.
Response variables involved include:
Oxygen vs deoxygenated atmosphere (during pyrolysis),
Bath vs spray vs no application (method of sizing).
Control variables include:
Fiber & Sizing,
Fiber resin ratio,
Fiber Length,
Pyrolysis Time & Temp.
Post-pyrolysis fibers will then be chopped, blended with plastic (polymer TBD) and extruded, cut into pellets, and injection molded into dog-bones for tensile testing. The resulting mechanical properties of the carbon fiber reinforced plastic compared with standard injection molding polymers as well as fully-cured composite.
Although uncertainties exist in the viability of sizing application and surface treatment for composites recycling, building upon previous work in pyrolysis and utilizing the unique resources available at BYU (composites lab, ready access to aerospace-grade fibers, industry standard processing equipment, scanning electron microscopes, etc.), the work's importance and potential for contributions to the field are clear.