In-situ pyrolysis: A novel technique for the dispersion of carbon particles in thermoplastics

Abstract

An adequate dispersion of fine particles is essential for improved properties in particle-reinforced composites. State-of-the-art methods mainly rely on mechanical (shearing) dispersion methods that do not yield the requested homogeneity within the final composite. This leads to a deterioration and inhomogeneity of mechanical properties. Other non-conventional methods such as in-situ polymerisation or solution compounding are not yet applicable on an industrial scale. This study tackles these problems and provides a novel method for the fabrication of well-dispersed particle-reinforced polymer composites while making use of conventional machinery on the one hand and allowing industrial applicability on the other hand. The presented technique makes use of the pyrolysis of a low thermally stable polymer within a conventional melt compounding process to produce well dispersed carbon particles throughout a thermoplastic matrix in an in-situ process. For this purpose, Carboxymethylcellulose particles are used. The selection of decomposition parameters around the processing temperature of polypropylene yields well-dispersed carbon particles, as evidenced by scanning electron microscopy. This further interprets the resulting promising mechanical properties.