Polyamide‐6 structure modification by combined solid‐phase extrusion

Abstract

Methods of wide‐angle X‐ray analysis and transmission electron microscopy were performed to investigate structural and phase transformation occurring in polyamide‐6 (PA‐6) by combined solid‐phase processing including extrusion through a conical die (ED) and the following equal‐channel multiple‐angular extrusion (ECMAE). It was shown that high level of plastic and strength characteristics of extruded PA‐6 is determined by the formation of a duplex structure consisting of elongated disoriented fiber‐like entities and fragmented globular formations. Conservation of high values of plasticity of deformed PA‐6 is also controlled by the transition of the crystals of α‐form to the crystals of γ‐form with higher plasticity reserve. We have established rational technology parameters of PA‐6 processing by ED‐ECMAE processes (the deformation degree εED at ED, deformation intensity ΔΓ and the value of accumulated deformation εECMAE at ECMAE). POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers

Control of the mechanical and thermal properties of semicrystalline polymers via a new processing route of the equal channel multiple angular extrusion

“…Equal‐channel multiple angular extrusion (ECMAE) seems the most promising variant of ECAE because it provides change of space orientation of shear planes, intensity and value of accumulated strain for one pass . Using ECMAE makes possible formation of unique set of properties of semicrystalline polymers: high density and deformation‐strength characteristics with the minimal anisotropy .…”

Mechanical Reinforcement of Polyamide 6 by Cold Hydrostatic Extrusion

“…Polyamide 6 can be processed with various techniques, including: selective laser sintering (SLS) [41], twin-screw extrusion (TSE) and cold-drawing (DR)-TSE DR [42], Equal-Channel Multiangular Extrusion (ECAP) [43], solid-phase extrusion (CE) [44], injection With an increase in the degree of true strain during the HE processes, an increase in all measured mechanical properties is observed. However, compared to the initial state material (A), the values obtained in the compression test, i.e., the compressive modulus (E c ) and the compressive strength (σ M ), are lower over the entire range of strain values.…”

Severe Plastic Deformation of Polymers

“…86) Specifically, in a sequential solid-state extrusion through a conical nozzle followed by ECMAE, a fibrillar structure formed in the first step gets fragmented in the second one, in which the fibrils are partially rotated. 74) This leads to a duplex structure consisting of stretched randomly oriented fibril-like formations up to 10 nm in diameter and 100150 nm in length, as well as some 1020 nm sized globules. It is similar to the structure of a composite that contains randomly oriented fibrils in its polymer matrix, which provides a combination of high strength and ductility.…”