Nanocomposites and nanomaterials

Reinforcing effect caused by equal channel angular extrusion of polymers manufactured by the FDM process: Experimental investigation and mathematical modeling
V. Beloshenko,1 Y. Beygelzimer,1 Yu. Voznyak 2, A. Voznyak3
1Donetsk Institute for Physics and Engineering named after A.A. Galkin, National Academy of Sciences of Ukraine, Kyiv 03028,Ukraine
2Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Lodz 90363, Poland
3Donetsk National University of Economics and Trade named M. Tugan-Baranovsky, Kurchatov Street, 13, 50042 Krivoy Rog, Ukraine
E-mail: avvoznyak76@gmail.com

Nowadays, high attention is paid to development of methods of reinforcement of polymers in order to form new or enhanced characteristics (improved Young modulus, ductility, light weight, flame retarding ability, etc.). There are two main techniques for improving polymer properties: orientation and reinforcement. Reinforcement with organic and inorganic fibers or fillers like nanoparticles as well as hybridization with different nanofibers or nanofillers provides materials with unusual combinations of mechanical, thermal, and chemical properties. 
Being also referred to as self-reinforcement, orientation is another technique of production of materials with superior properties by modification of the polymers’ chain structure in the course of processing. The basic methods of production of self-reinforced polymeric materials are cold drawing, rolling, solid-state hydrostatic or ram extrusion, solution spinning, and melt transformation extrusion or coextrusion. These methods are quite different; however, the fundamentals are the same. During these processes, a reorganization occurs that is related to the orientation and transformation of the initial microstructure into a nanofibrillar one. At the moment, equal-channel angular extrusion (ECAE) is an innovative process that affects the microstructure through extreme uniform severe plastic deformation by simple shear. Contrary to the aforementioned methods of self-reinforcing of polymeric materials, ECAE is a process that preserves the sample shape i.e.,  deformation is not accompanied by geometric necking.
In this study, we examined the applicability of ECAE for improving the physical and mechanical properties of glassy and semicrystalline polymers with respect to orientation direction of the melt layers in the original billet. In addition, we considered structure modification of fused deposition modeling (FDM) -produced layered composites made of them.