Novel, highly-filled ceramic–polymer composites synthesized by a spouted bed spray granulation process

• Published in: Composites science and technology 2014-01, Vol.90, p.154-159
• Main Authors: Wolff, M.F.H., Salikov, V., Antonyuk, S., Heinrich, S., Schneider, G.A.
• Format: Article
• Language: English
• Subjects: Applied sciences; B. Mechanical properties; Composite; Composites; Exact sciences and technology; Filling degree; Forms of application and semi-finished materials; Granulation; Polymer industry, paints, wood; Spouted bed; Technology of polymers
• ISSN: 0266-3538; 1879-1050
• DOI: 10.1016/j.compscitech.2013.11.006

We present a novel processing route to synthesize homogeneous ceramic polymer composites with ultrahigh (∼78vol.%) packing density by using the spouted bed granulation technology and subsequent warm pressing. In the granulation process, two ceramic particle size fractions (α-Al2O3) and a thermoplastic polymer (polyvinyl butyral) are assembled to granules. In the process, μm-sized particles are coated with a layer of polymer which contains a second, nm-sized ceramic particles fraction. The mass fractions of each constituents can be adjusted independently. During the warm pressing, the nm-sized particle fraction along with polymer is pressed into the void volume of the μm-sized particles, thus achieving a homogeneous, isotropic composite structure with a very high packing density of ceramic particles. The material, which can easily be produced in large quantities, combines a high modulus of elasticity (up to 69GPa), tensile strength (∼50MPa), and pronounced fracture strain (∼0.1%) with an isotropic, biocompatible, metal-free composition. Possible failure mechanisms are discussed, including failure due to necking of the polymer, and failure due to limited polymer–particle-interfacial strength.