Preparation and characterization of shape memory polymer based composite materials for aerospace applications

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2015

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Ersaraç, Feride Nur

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Most aerospace industries are working on the adaptive structures by using shape memory (SM) materials in order to increase the flight performance. Shape Memory Materials are smart materials that have the capability of return from temporary shape to the permanent shape upon application of an external stimulus. The main objective of this study is to develop a shape memory polymer in a thermoset structure where the triggering mechanism is heating and to investigate its applicability in aerospace field. The SM polymeric resin was synthesized by mixing epoxy monomer and diamine curing agent with different concentrations of Neopentyl Glycol Diglycidyl Ether (NGDE) as epoxy modifier. DSC, DMTA, FTIR, SEM analyses and mechanical tests (tension, impact tests) were applied in order to characterize the SM polymer. Shape recovery ratio and time were determined by applying bending tests. The SM polymer with 8% NGDE content revealed the best mechanical and SM performance. Different concentrations of carbon nanotubes (CNTs) were added to iv 8% NGDE sample to create an electrical resistance which would provide heating the material by electrical current. The sample containing 1% CNTs showed the best mechanical properties, while 2% CNT content showed the lowest electrical resistivity. Lastly, carbon fabric reinforced composites with four different resin matrices were produced for investigation of aerospace applicability. Compression test, SEM analysis, electrical resistivity measurements and bending tests (in oven and by electrical heating) were carried out. The composite that was produced with unmodified system showed 86% shape recovery, whereas modified resin system showed 96-97% with shorter shape recovery times.

Subject Keywords

Shape memory polymers., Aerospace engineering, Polymeric composites., Epoxy resins.

URI

http://etd.lib.metu.edu.tr/upload/12619494/index.pdf
https://hdl.handle.net/11511/25171

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Graduate School of Natural and Applied Sciences, Thesis

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Citation Formats

F. N. Ersaraç, “Preparation and characterization of shape memory polymer based composite materials for aerospace applications,” M.S. - Master of Science, Middle East Technical University, 2015.