Preparation and Properties of Low Dielectric Loss Vinyl Resin Materials

To meet the challenges brought by the rapid development of modern communication technology, new resin materials need to be developed for copper clad laminate (CCL) which could be applied in order to achieve better performance in high-frequency applications. In this work, a vinyl resin (VLBPA) was prepared by Williamson etherification of bisphenol A (BPA) and 4-vinyl benzyl chloride (VBC). The structure and properties of VLBPA were characterized by HPLC, ¹H-NMR, FT-IR and differential scanning calorimetry (DSC), and the optimal synthesis condition of the product was studied. Then the cured VLBPA resin was prepared by vacuum hot compression moulding at following preparation method: VLBPA resin was compressed at 145 ℃ for 1.5 h, then the temperature was raised to 175 ℃ for 2 h, followed by 210 ℃ for 4 h. The thermal stability and dielectric properties of the cured VLBPA resins were analyzed by thermogravimetric analysis(TGA) and dielectric spectrometer. The results show that an optimized yield of VLBPA can be achieved when n(BPA)∶n(VBC)∶n(NaOH) is 1.0∶2.8∶2.4, which is 92.76%. DSC analysis results show that the melting point of VLBPA is 117.7 °C and the crosslinking of vinyl groups happens at the temperature of 156.3 °C. The TGA results indicate that the 5% weight loss temperature of the cured resins under nitrogen atmosphere is 400.5 ℃. Dielectric property tests of cured resin were performed at 10 GHz condition. The average value of the dielectric constant (D_k) and the dielectric loss (D_f) is 2.79 and 0.0065, respectively.