Thesis
Recycling of fiber reinforced epoxy composite wastes
Washington State University
Master of Science (MS), Washington State University
2017
Handle:
https://hdl.handle.net/2376/103184
Abstract
Fiber reinforced plastics (FRPs) are indispensable to aerospace, automotive, sporting-goods and wind energy industries due to their outstanding mechanical performances apart from high thermal and dimensional stabilities as well as chemical resistance. Thermosetting polymers cannot be processed and reshaped once cured; therefore, recycling of FRP composites after use is challenging. Currently, most FRP wastes end up in landfill, which takes no advantage of their residue value but increases environmental burdens. In this thesis, two mild chemical recycling approaches of epoxy based FRP wastes were developed using efficient catalyst systems. It was found that ZnCl2/ethanol was effective in the degradation of amine-cured epoxy; while phosphotungstic acid aqueous solution was effective in the degradation of anhydride-cured epoxy. The recycled fibers displayed clean and smooth surfaces, suggesting little damage to the fibers during the degradation process; thus, they could be reused as reinforcement with little or no compromise on their original performances for new composites. The decomposed matrix resins were in oligomer forms; when added as reactive ingredient in new epoxy curing system, the results showed that the regenerated epoxy could compete with virgin epoxy resins. In addition, a proper use of FRP prepreg waste, which account for 20-30 wt % of nonwoven laminates during the FRP manufacturing process was introduced. It was found that the prepreg waste could be used as effective reinforcement for engineering thermoplastics, such as polyamide 6. At a loading of only 10 wt%, the modulus, tensile strength, and impact strength of polyamide 6 were increased by 221%, 69%, and 40%, respectively.
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Details
- Title
- Recycling of fiber reinforced epoxy composite wastes
- Creators
- Xiaolong Guo
- Contributors
- Jinwen Zhang (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Mechanical and Materials Engineering, School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900525283501842
- Language
- English
- Resource Type
- Thesis