Investigation of Poly(olefin Sulfone) Depolymerization and its Dust Mitigation Abilities for Potential use on Spacecraft

Salt Lake Community College Westpointe Campus, Salt Lake City, UT

The ubiquity of particulate contamination requires dust mitigation techniques to provide low-scatter surfaces and edges on sensitive optical devices in space. Poly(olefin sulfone)s have been shown to photodegrade with the assistance of a photobase generator when exposed to UV light (254 nm) and heat (120°C). These may be applicable to minimizing dust on optical surfaces for space applications. However, their behavior in vacuum has not been fully characterized. We synthesized poly(2-methyl-1-pentene sulfone) (PMPS) and poly(1-hexene sulfone) (PHS) with and without a photobase generator. We studied the photodegradation (172 nm or 254 nm) of thin films in vacuum. Spectroscopic ellipsometry was used to quantify film thickness over time. The PMPS and PHS films both degraded when exposed to UV light in vacuum, though PHS to a lesser degree. We found that heat was not required to cause degradation, and that degradation occurred with UV irradiation even without a photobase generator. We also found that the degradation process removes dust particles from a surface. This investigation shows that poly(olefin sulfone)s could be used to protect optical surfaces until their deployment in space.