Conducting polymer polyparaphenylene (PPP) was synthesized from c/s-dihydrocatechol (DHCD) obtained from bacterial transformation of benzene. Results showed that the DHCD to DHCD-DA (diacetate) synthesis process produced some byproducts as impurities including trace amounts of phenol, quinone, and phenyl acetate derived from phenol. These impurities played a negative role in the polymerization process of DHCD-DA to P(DHCD-DA). In this study, a distillation fractionation method was employed to obtain monomer DHCD-DA with high purity and high yield. Four different polymerization methods using the purified DHCD-DA, including bulk polymerization initiated by different catalyst systems, solution polymerization as well as emulsion polymerization, were compared. A very high P(DHCD-DA) yield of 92% with a molecular weight of 84,500 was obtained under an optimized condition using the bulk polymerization process initiated by (di)benzoyl peroxide (BPO) and ferrous sulfate. A standard curve was established to evaluate the aromatization degree of P(DHCD-DA) to PPP under different temperatures based on the intensity of FTIR absorption and functional groups on the PPP. The glass transition temperature and the crystallinity of PPP increased with the degree of aromatization of the prepolymer P(DHCD-DA). Thermal analysis indicated that the PPP possessed high thermal stability both in nitrogen and in air atmospheres. All these results would help the synthesis of PPP.
All Science Journal Classification (ASJC) codes
- Surfaces, Coatings and Films
- Polymers and Plastics
- Materials Chemistry