Doctoral Dissertations
Date of Award
8-2025
Degree Type
Dissertation
Degree Name
Doctor of Philosophy
Major
Energy Science and Engineering
Major Professor
Chad E. Duty
Committee Members
Chad E. Duty, Amber M. Hubbard, Matthew Korey, Uday Vaidya, Soydan Ozcan
Abstract
With the increased demand for sustainable materials and processes, there has been significant academic and industrial interest in the exploration of recycled polymers and polymer composites for advanced engineering applications. In particular, manufacturing technologies such as large format additive manufacturing (LFAM) warrants further investigation as a potential source for material recovery, given its increasing market share and the costs, energy demands, and the compositional complexity of the materials utilized. However, there are still limitations in the industrial adoption of recycled materials as feedstock for LFAM applications, especially related to the potential material performance degradation that may result due to recycling and remanufacturing pathways. This dissertation aims to identify material streams of interest, characterize the effects that recycling and remanufacturing contributes to material degradation at pilot scale, and to demonstrate potential advantages to utilizing recycled materials in LFAM applications. The findings demonstrate that, while some degradation occurs, recycled carbon fiber acrylonitrile butadiene styrene (CF-ABS) can retain sufficient performance as an LFAM feedstock when processed through controlled remanufacturing pathways. Multiple viable CF-ABS waste streams were identified, the influence of intermediate manufacturing processes on material degradation was characterized and evaluated using statistical modeling, and specific advantages to using recycled CF-ABS were demonstrated. This work provides a pilot-scale assessment of CF-ABS recyclability and contributes practical insights to guide material selection and process optimization for more sustainable manufacturing practices.
Recommended Citation
Walker, Rebecca C., "Development of Recycled Short Fiber Acrylonitrile-butadiene-styrene for Large Format Additive Manufacturing Applications. " PhD diss., University of Tennessee, 2025.
https://trace.tennessee.edu/utk_graddiss/12781