To reach new horizons, several teams around the world are looking to improve technologies used in spacecraft. In Quebec, the CREPEC Vision group is dedicated to the development of a lunar rover prototype built with a thermoplastic composite chassis. This choice of materials allows manufacturing the chassis by 3D printing, in addition to opening the door to repairs during the missions. However, polymers do not disperse the charges present in the lunar environment as well as the aluminum currently used. Radiation in the lunar environment induces charges that can trigger electrostatic discharges that are damaging to fragile electronics. Therefore, a way must be founded to increase the protection offered by the highperformance polymers that the team intends to use, namely PEEK and PEI.
The objective of this thesis is to discover the best additive to increase the conductivity of these polymers above the threshold of 10-11 S·m-1 and thus ensure that the charges will be dissipated.
To achieve this, samples composed of one of the two polymers with one of three additives (carbon black, graphene or carbon fibers) are made at different concentrations using a microextruder. Then, the dielectric properties are measured using broadband dielectric spectroscopy at temperatures ranging from 25 °C to 200 °C, to encompass the range of daytime temperatures of the lunar environment which can reach 120 °C.
For both PEEK and PEI, analysis of the results shows that the best additive, of the three tested, is carbon black. In fact, it is the one that generates the lowest percolation threshold (12 % by mass), in addition to procuring the highest conductivity (more than 10-8 S·m-1) for high performance polymers.
| Date | 12 Apr 2021 |
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| Original language | French |
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| Awarding Institution | - École de technologie supérieure
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| Supervisor | Éric David (Supervisor) |
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Leblanc, F. (Author),
David (Supervisor),
12 Apr 2021Student thesis: Master's thesis › Master in Engineering: Mechanical Engineering