Deposition of silicate coatings on poly(ethylene terephthalate) for improved scratch and solvent resistance

Abstract

The surface of poly(ethylene terephthalate) (PET) films crystallizes when exposed to a broad class of organic solvents (protic polar, aprotic polar, and non-polar). This phenomenon leads to irreversible changes in transparency and mechanical properties. It also limits PET films and coatings in applications including electronics, medicine, packaging, and construction. This work describes a method to impart solvent resistance to the PET surface by depositing a silicate film. This coating enables many post-functionalization options, including those that tune wettability or impart antifouling characteristics to the parent PET surface. It also endows PET surface resistance to organic solvent exposure without affecting the overall mechanical and optical properties of the PET. Additionally, the silicate layer improves the scratch resistance of PET surfaces.