Transparent hydrophobic durable low moisture permeation poly(fluoroimide acrylate)/SiO2 nanocomposite from solventless photocurable resin system

Abstract

In this article, we report a novel high performance nanocomposite made from environmentally friendly and energy conserving solventless photocurable patternable resin system. The system contains a fluoroimide acrylate oligomer, acrylate monomer, photoinitiator and SiO₂ nanoparticles. The fluoroimide acrylate oligomer was synthesized by reacting 2 mole equivalent of 4,4′-(hexafluoroisopropylidene) diphthalic anhydride (6FDA) with 4,4′-(hexafluoroisopropylidene) diamine (6FpDA) first to form fluoroimide dianhydride, and then further reacting with 2 moles of 2-hydroxy ethyl methacrylate (HEMA). The fluoroimide acrylate oligomer was specially designed with carboxylic acid functionality. As compared with bis-phenol A acrylate oligomer, the fluoroimide acrylate oligomer nanocomposite shows an improvement in both physical properties and chemical properties. This new nanocomposite exhibits good cross hatch adhesive strength (>95% on glass) and unusually high hydrophobicity (>140° contact angle). The nanocomposite also shows excellent transparency (>90% transmission at 400–800 nm for 100 μm film), high thermal stability and mechanical durability. The water absorption and the water vapor permeation of this nanocomposite are reduced to at least one quarter of those of the bis-phenol A acrylate nanocomposite. The chemical characteristics of the fluoroimide acrylate and the formation of nanodomains in the nanocomposite play major roles in providing the outstanding performance.