Preparation, characterization and properties of fluorinated and non-fluorinated copolymers of cyanate esters

Abstract

Cyanate ester resins or polycyanurates are of a class of promising high performance thermosetting polymers, which possess highly desirable chemical and physical properties for various applications. However, the functional properties of polycyanurates such as dielectric and optical properties have not been studied systematically. The preparation and characterization of dielectric and optical polycyanurate thin films is a new and interesting research area and has new potential applications. As a part of this research work, optical quality thin films of polycyanurate homopolymers and copolymers have been prepared through optimizing the polymerization conditions, spin coating parameters and thermal curing procedures. Polycyanurates and their thin films were characterized by FTIR (Fourier-Transform Infrared), DSC (Differential Scanning Calorimetry), TGA (Thermogravimetric Analysis), AFM (Atomic Force Microscope), DEA (Dielectric Analysis), Prism Coupler, and Nano-indentation. In addition, new curing kinetics models for aromatic and aliphatic polycyanurates were established. The dielectric studies of the polycyanurate homopolymers and copolymers revealed that the heterogeneity of the polymer can be quantified using the Cole-Cole plot based on the DEA data. This method is a sensitive way of comparing heterogeneity in polymer systems, and such subtle differences in heterogeneity may not be detectable using conventional techniques such as DSC.