CVD Deposited Epoxy Copolymers as Protective Coatings for Optical Surfaces

Abstract

Copolymer thin films of glycidyl methacrylate (GMA), ethylene glycol dimethacrylate (EGDMA) and 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane (V4D4) were synthesized via initiated chemical vapor deposition (iCVD) as protective coatings for optical surfaces. Chemical durability in various solvents, corrosion resistance, adhesion to substrate, thermal resistance and optical transmittance of the films were evaluated. Crosslinked thin films exhibited high chemical resistance to strong organic solvents and excellent adhesion to substrates. Poly(GMA-co-EGDMA) and poly(GMA-co-V4D4) copolymers demonstrated protection against water (<1% thickness loss), high salt resistance (<1.5% thickness loss), and high optical transparency (~90% in visible spectrum) making them ideal coating materials for optical surfaces. Combining increased mechanical properties of GMA and chemical durability V4D4, the iCVD process provides a fast and low-cost alternative for the fabrication of protective coatings.

Designing Organic and Hybrid Surfaces and Devices with Initiated Chemical Vapor Deposition (iCVD)

“…Optical protective coatings were synthesized using three homopolymers; p(GMA), p(EGDMA), and p(V4D4); and two copolymers, p(GMA‐co‐EGDMA) and p(GMA‐co‐V4D4). [ 97 ] Tests were carried out using 350 to 400 nm thick films. The 3‐membered epoxy ring functionality of the GMA unit is anticipated to promote adhesion and mechanical durability.…”