Properties of melt processable PTFE/PEEK blends: The effect of reactive compatibilization using electron beam irradiated melt processable PTFE

Abstract

For the first time, blends of melt processable polytetrafluoroethylene (MP PTFE) with polyetheretherketone (PEEK) in the MP PTFE/PEEK ratio of 100/0, 80/20, 50/50, 20/80, and 0/100 w/w were prepared and characterized. MP PTFE/PEEK blends are attractive materials due to the combination of low coefficient of friction and universal chemical resistance of MP PTFE with good wear resistance and mechanical strength of PEEK while maintaining high thermal stability of both. Miscibility, phase morphology, and mechanical properties of the new MP PTFE/PEEK blends were investigated. To improve their end-use properties, an attempt of reactive compounding with the electron beam irradiated MP PTFE (e-beam MP PTFE) was made. The reactive compounding was done in two steps, that is, the preparation of a masterbatch (MB) consisting of e-beam MP PTFE/PEEK (50/50 w/w) and subsequent melt blending of MP PTFE/ PEEK with varying concentrations of MB. The e-beam irradiation of MP PTFE carried out in air atmosphere and at room temperature with a dose of 50 kGy results in its chain scission associated with formation of ACOF and ACOOH functional groups. Such modified MP PTFE can be used to compatibilize MP PTFE/PEEK blends. Reactive compatibilized blends exhibit improved phase morphology and mechanical properties. Especially for MP PTFE/PEEK 50/50 blends, a great improvement of almost 250% in strain at break, 40% in stress at break, and more than 600% in toughness was achieved. the very high melt viscosity of PTFE its processing is limited to, for example, sintering process, whereas MP PTFE, characterized by lower melt viscosity, can be processed by the conventional melt processing methods. Consequently, only PTFE blends with less than 30 wt % (weight percent) of PTFE can be produced by a melt extrusion process otherwise only a compression moulding process is possible. 5 Moreover, due to the high melt viscosity of PTFE, melt blending of PTFE powder in polymer matrix results in filler-matrix morphology. The tendency of the PTFE powder to agglomerate and a lack of an adhesion between PTFE phase and the polymer matrix are responsible for the reduced mechanical properties of PTFE blends. In contrast to PTFE blends, in MP PTFE blends, the lower viscosity of MP PTFE enables its better dispersion and distribution within the polymer matrix. Thus, in comparison with PTFE blends, better mechanical performance for MP PTFE blends is expected.

Effect of Aging on the Mechanical Properties of Highly Transparent Fluoropolymers for the Conservation of Archaeological Sites

“…In the PFA film, the main effects shown are due to the CF 2 vibrations (at 1200 and 1145 cm −1 ), but, after aging, the spectrum (given in Figure 14 ) showed the presence of OH groups (3349 cm −1 ) and the absorbance of C=O groups (1743 cm −1 , 1654 cm −1 , and 1589 cm −1 ) related to the COOH groups, due to the degradation of the molecular chains during the aging process [ 12 ].…”

“…The behavior of the aged PFA can be explained by considering the chemical structure of the polymer, which is schematically represented in Figure 15 . Indeed, the ether group can be attacked during the aging process and COOH groups can be introduced [ 12 ].…”

“…In order to evaluate how ETFE films can be useful in this specific application, the present work focused on defining the mechanical resistance, especially the tearing and impact properties, before and after an accelerated aging process, in accordance with several studies about the resistance of blown cushions [ 11 , 12 ]. Indeed, by measuring the changes in the film after the aging treatment, chosen for representing a period of outdoor application close to the conditions of the real situation, the performance of the selected ETFE films can be assessed.…”

Effect of Fiber Type and Content on Mechanical Property and Lapping Machinability of Fiber-Reinforced Polyetheretherketone

“…The material properties of the fiber-reinforced PEEK vary with different fiber types. The fibers commonly used for PEEK reinforcement include carbon fiber, glass fiber, graphite fiber, and polytetrafluoroethylene (PTFE) fiber [ 4 , 5 , 6 , 7 ]. Carbon fiber has certain advantages, such as high strength, high modulus, small thermal expansion coefficient, and superior machinability [ 8 , 9 ].…”

Controllable design of polytetrafluoroethylene chemical component using the “harmful” irradiation heat

“…Due to the excellent characteristics such as chemical inertness, thermal stability and abrasion resistance, polytetrafluoroethylene (PTFE) micropowder has been widely used as additive in thermoplastics, coatings, inks and greases. [1][2][3][4][5] Generally, there are three ways to prepare PTFE micropowder: direct polymerization, 6-8 pyrolysis [9][10][11][12] and high-energy irradiation. [13][14][15] Compared with the other two methods, high-energy irradiation had a greater destructive effect on polymer materials, which led to degradation of polymers.…”