Structure and thermal stability of phosphochlorinated polybutadiene/carbon black composite synthesized via oxidative chlorophosphorylation reaction

The aim of the presented work was to obtain a new type of homogeneous composite based on an industrial polymer (polybutadiene, PB) and a well-known inexpensive filler (carbon black P-234, CB). For this purpose, the reaction of oxidative chlorophosphorylation (OxCh) was used. This makes it possible to introduce CB into the cross-linked structure of the modified polymer and ensure optimal distribution of the filler in it. The structure and thermal stability of the composite synthesized by the OxCh reaction were studied. Analysis of the composite by Fourier-transform infrared spectroscopy indicates a uniform distribution of carbon black in the network structure of the matrix and the physical interaction of the phases of the composite. Ultraviolet-visible spectrum data confirmed the improvement in light absorption in a wide range of the electromagnetic spectrum and the decrease in the optical band gap energy of the phosphochlorinated PB (PhPB) matrix with the addition of CB (Eg of PhPB=3.25 eV; Eg of PhPB/CB composite=2.28 eV). The influence of CB on the thermal stability of the PhPB matrix was studied using thermogravimetric and differential thermogravimetric analysis. After thermal analysis, the char yield for PhPB was 41 wt%, and for PhPB/CB composite was 35.2 wt%. Compared to PhPB, the increase in char yield, the decrease in maximum thermal decomposition temperature, and the high-integrated thermal decomposition temperature for the PhPB/CB composite show the improvement in the thermal stability of PhPB due to CB.