Low dielectric constant and high toughness epoxy resin based on hyperbranched polyester grafted by flexible chain modified

A new kind of hyperbranched polymers was designed and prepared with flexible chain blocking in this paper. Not only the flexible chain blocking hyperbranched polyester could be used for a toughening agent about epoxy resin and the impact strength reached 29.8kJ/mm(2), but also reduces greatly the dielectric constant and the dielectric loss of the epoxy resin, and the lowest dielectric constant was 2.73 (10(7) Hz), as well the lowest dielectric loss was 0.002 (10(7) Hz), compared with the epoxy resin system modified with the traditional hyperbranched polyester. The results indicated that the flexible chain blocking hyperbranched polyester had offered free volume structure and flexible chain with epoxy resins chain formed the interpenetrating polymer networks which made transformation accomplish. The resins which had better toughness, low D-k, low dielectric loss and excellent insulation performance could be applied in various research and development fields, such as high frequency and low dielectric copper clad laminate and translucent structural adhesives, etc.