Curing reaction and properties of a kind of fluorinated phthalonitrile containing benzoxazine

Introducing of fluorinated substituents into molecular chains was an efficient way to prepare materials with decreased dielectric constant and loss. In this work, a kind of fluorinated phthalonitrile containing benzoxazine (BPAF-ph) was synthesized. Curing reactions and processability were investigated by DSC and dynamic rheological analysis (DRA). Non-isothermal curing kinetics analysis was applied to calculate the activation energy of BPAF-ph. Results showed that BPAF-ph exhibited obvious double-stage curing reaction behaviors and good processability. Based on the results of DSC and DRA, cured BPAF-ph was firstly fabricated at 200 degrees C. Then, BPAFph matrix resin was treated with different post heat-treatment procedures. Generated structures and properties of BPAF-ph matrix resins with different post curing procedures were investigated. Results showed that generated structures could be obviously influenced by the curing procedures. Relative low dielectric constants and loss of cured BPAF-ph was obtained and could be decreased with increasing of curing degree. BPAF-ph matrix resins also possessed good thermomechanical properties (50-250 degrees C: CTE - 41.1 ppm/oC; Tg - 327 degrees C) and thermal stability (T5%> 450 degrees C). Additionally, glass fiber reinforced BPAF-ph composites were prepared and their properties were investigated.

Automated summary

Introduction of fluorinated substituents in molecular chains is an efficient method to prepare materials with decreased dielectric constant and loss, as demonstrated in the synthesis of a kind of fluorinated phthalonitrile containing benzoxazine. The cured BPAF-ph showed double-stage curing reaction behaviors and good processability, with structures and properties being influenced by different post curing procedures. The glass fiber reinforced BPAF-ph composites exhibited promising properties in terms of thermal and mechanical stability.