Graphite Oxide as a Dehydrative Polymerization Catalyst: A One-Step Synthesis of Carbon-Reinforced Poly(phenylene methylene) Composites

Abstract

The synthesis and characterization of poly(phenylene methylene) (PPM) and carbon composites thereof are described. The materials were prepared using graphite oxide (GO), which was discovered to function in two distinct roles. First, the GO was found to facilitate the dehydrative polymerization of benzyl alcohol (BnOH) to form PPM. Second, the residual carbon from the GO catalyst, having undergone thermal deoxygenation during the polymerization reaction, served as a graphene-like-additive in the resulting composite. While pure (i.e., additive free) PPM was found to be mechanically compliant (E' = 40 MPa), inclusion of 0.1 wt % GO in the starting reaction mixture improved the material's mechanical properties significantly (E' = 320 MPa). Homogeneous dispersion of the additive in the matrix was confirmed by powder X-ray diffraction (PXRD) analysis, Raman spectroscopy, and transmission electron microscopy (TEM). The carbon additive was separated from the PPM via trituration in dichloromethane, and the GO starting material (C:O ratio = 2.0:1; sigma = 445 x 10(-5) S m(-1)) was found to have undergone significant reduction during the polymerization reaction (C:O ratio = 12.3:1; sigma = 801 S m(-1)). Moreover, the recovered carbon did not assemble into graphite-like aggregates, as determined by PXRD, Raman spectroscopy, and TEM, which indicated that the PPM matrix was able to effectively disperse the additive.