Titanium/polymer sheets designed for biomedical application; Feasibility study

• Applicant: Professor Dr.-Ing. Heinz Palkowski
• Subject Area: Biomaterials ; Solid State and Surface Chemistry, Material Synthesis ; Synthesis and Properties of Functional Materials ; Primary Shaping and Reshaping Technology, Additive Manufacturing
• Term: from 2017 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 386107554

The research group of IMET, TU Clausthal, and IPCMS, Uni Strasbourg, is working together since a decade of years developing and characterizing sandwich sheet materials of metal/polymer combinations for automotive applications. It extended its activities into the field of biomedical use with new challenges concerning the combination of biocompatible materials some years ago. As the use of epoxy resins, uncritical for the automotive, is not applicable for biomedical use, new ways for a good and safe bonding are necessary to be developed for these combinations of metal and polymer materials. The goal of the general project is the design of new titanium(Ti)/polymer(P)/Ti hybrid sheets to be used for biomedical applications, the control of their interface, their mechanical properties and shaping behavior. The advantages of these systems usable for cranioplasty and mandible surgery will be a lightweight multilayer system with graded strength conditions and improved thermal and acoustic properties with respect to titanium alone, and with mechanical properties that can be designed close to the bones ones. The elaboration of these systems, the process development, the analysis of the properties and their forming limits is foreseen to be performed in synergy between the French and German partners with the main objectives:1) Use a new developed chemical process to design P/Ti interfaces free of epoxy resins currently used as adhesive agents in sandwich sheets (SMs) for automotive applications. 2) Fabricating Ti/P/Ti or Ti/P SMs for cranioplasty and mandible surgery with tailored mechanical properties close to the bones behaviour.Up to now, the new grafting from method, investigated by IPCMS, could successfully be introduced for a Ti surface 10 x 10 mm². A polymerization initiator could be grafted on a modified Ti (Grade 1) sheet surface via a phosphonate anchor. Linear polymer chains of polymethylmethacrylate (PMMA) could be grown from the initiator using a controlled radical polymerization process up to a thickness of approximately one micron. The aim of this short time project (9 months) is to investigate the feasibility of using this grafting from method to produce sandwich sheets (aiming at size A6 or even A5). The results are foreseen to be used for a new, strengthened and final bilateral project within the next DFG-ANR program.The steps foreseen are to1. prepare the metal sheet surface in a homogeneous way without defects or strongly (weakening?) differences in the layer coated on the metal,2. find suitable process conditions for combining the single layers to a sandwich sheet with a3. suitable, reproducible bond.

• DFG Programme: Research Grants