Synthesis and properties of cured epoxy mixed resin systems modified by polyphenylene oxide for production of high‐frequency copper clad laminates

Redistributed polyphenylene oxide (rPPO) was synthesized and used to modify epoxy resin for use as high‐frequency Copper Clad Laminates (CCLs). The chemical composition, thermal stability and micro morphology of cured rPPO/(Epoxy resin)EP mixed resin systems were analyzed and their mechanical, thermal conductivity and dielectric properties determined. These results revealed that the molecular weight of rPPO containing 20 wt% bisphenol A (BPA) was greatly reduced, with a number‐average molecular weight of rPPO as low as 2652.7. Cured rPPO/EP mixed resin systems were prepared with improved heat resistance properties, exhibiting a maximum heat weight loss temperature ( T d50 %) of 421°C, that was 151°C higher than that observed for pure epoxy resin. Scanning results show that reducing the molecular weight of PPO effectively improves the compatibility with E‐51. Broadband dielectric spectrum analysis revealed that the cured rPPO/EP mixed resin systems had a lower dielectric constant (3.76/10 7 Hz) and a smaller dielectric loss of 2.11 × 10 −3 /10 7 Hz than pure epoxy resin. Similarly, composite laminates derived from cured rPPO/EP mixed resin also showed a lower dielectric constant (4.65/10 7 Hz) and dielectric loss (6.25 × 10 −4 /10 7 Hz) than laminates derived from pure epoxy resin. POLYM. COMPOS., 39:E2334–E2345, 2018. © 2017 Society of Plastics Engineers