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

摘要

We present a novel processing route to synthesize homogeneous ceramic polymer composites with ultra-high (～78 vol.%) packing density by using the spouted bed granulation technology and subsequent warm pressing. In the granulation process, two ceramic particle size fractions (α-Al_2O_3) and a thermoplastic polymer (polyvinyl butyral) are assembled to granules. In the process, um-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 urn-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 69 GPa), tensile strength (～50 MPa), and pronounced fracture strain (～0.1%) with an isotropic, biocom-patible, 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.