Dual-curable fluorinated poly(methacrylate) copolymers for optical adhesives

• Published in: Polymers for advanced technologies 2005-06, Vol.16 (6), p.484-488
• Main Authors: Jang, Se-Chan, Yi, Sung-Chul, Kim, Yang-Bae, Hong, Jin-Who
• Format: Article
• Language: English
• Subjects: adhesives; curing of polymers; oligomers; optical communication; photo-curable
• ISSN: 1042-7147; 1099-1581
• DOI: 10.1002/pat.491

In pursuit of photo‐curable adhesive for optical communication, dual‐curable acrylic oligomers (AOs) having alkoxy silane group, fluorine atoms and vinyl group as a pendent group were synthesized by two‐stage reactions. The isocyanate group containing oligomers were firstly synthesized via radical polymerization of acrylic monomers, and followed by urethane reaction with 2‐hydroxy ethyl methacrylate. The dual curing behaviors, e.g. thermal and photo‐cure, were studied by using photo‐differential scanning calorimetry (DSC) and real‐time IR. An optimum adhesive formulation, based on AO (15 g), epoxy acrylate (80 g), isobonyl methacrylate (17 g) and photo‐initiator (3 g), was obtained. As the content of AO was increased in the optical adhesive formulation, refractive index decreased but transmittance increased due to the increase in fluorine content. The optical transmittance at the range of 1.3 to 1.55 μm was higher than 90%. The addition of colloidal silica with the earlier mentioned formulation was helpful in decreasing crosslinking volume shrinkage and the increasing of glass fiber adhesion. The required properties for the optical adhesive, including chemical resistance and thermal resistance, dimension stability, etc. were also investigated. Copyright © 2005 John Wiley & Sons, Ltd.