Propargyl-terminated Resins—A Hydrophobic Substitute for Epoxy Resins

Abstract

Propargyl derivatives of biphenols and phenol-formaldehyde resins (propargyl-terminated resins—PTRs) are being evaluated as non-polar matrices for advanced polymeric composites. The dipropargyl ether of bisphenol A and its B-staged materials are the most attractive candidates. PTR monomers are available in a one-step, easy preparation in quantitative yield from inexpensive starting materials. They are suitable for industrial production in large scale at a potentially low price. PTR thermosets based on different biphenols have a glass transition temperature above 300°C (572°F), and excellent isothermal thermo-stability in air and nitrogen which corresponds to that of the acetylene-terminated resins. In addition, they have low water absorption, low dielectric constant and dissipation factor, excellent physico-mechanical properties, etc. B-staging of PTR proceeds with a rearrangement of the propargyl group into a chromene ring. The final thermosets cure through polymerization of the chromene group. PTRs are a potential low cost substitute for epoxy resins for composites, adhesives, coatings and electronic applications.