PEEK and other Polyaryletherketones - May 2010

This month we're looking at PEEK and other types of Polyaryletherketones.

Polyaryletherketones (PAEK) are a key group of polymers which include PEEK, PEK, PEEKK and PEKK, with the 'E's and 'K's indicating the number and order of ether and ketone components in the monomer. The differing proportions of ether and ketone within these different compounds cause variations in the materials' properties, but in general they all perform well in high temperatures and other aggressive environments.

The strong performance of PAEKs mean they have found applications in almost every industry, particularly in demanding functions within Aerospace and Defence, Industrial Machinery, Automotive, Oil and Gas, and Medical Implant technology. As performance, quality and safety standards are raised, there are a growing number of applications where PAEKs will make the grade when the traditionally-used polymer won't.

Abstracts

Please see below a selection of abstracts highlighted in the May Newsletter. These are records which relate to PEEK or other types of Polyaryletherketones that have been recently added to the Polymer Library.

Click on the 7-digit accession numbers to find out about ordering a copyright-cleared full text copy of the items shown.

1061356 - PEEK: TITANIUM IN DIFFICULTIES (downloadable pdf available)
The use of PEEK for surgical implants, as a replacement for titanium and other metal alloys, is discussed. The main reasons for PEEK's success are shown be its mechanical properties, transparency to X-rays and biocompatibility. The use of PEEK in harsh environmental conditions is considered, together with its sterilisability and the biocompatibility requirements of the finished medical product. The results of biocompatibility tests on Evonik Industries' Vestakeep product family are presented. The need for consistent quality in medical devices is emphasised. Typical applications of PEEK include spinal implants, orthopaedic implants and dental implants.
Kunststoffe International, 100, No.2, 2010, p.41-43, ISSN: 1862-4243
Knebel M

1060679 - ENHANCED TRANSPORT PERFORMANCE OF SULFONATED MESOPOROUS BENZENE-SILICA INCORPORATED POLY(ETHER ETHER KETONE) COMPOSITE MEMBRANES FOR FUEL CELL APPLICATION
Sulphonated poly(ether ether ketone) (sPEEK)/mesoporous benzene-silica electrolyte composite membranes were prepared using a solvent casting method. The two components were mixed thoroughly in N,N-dimethyl acetamide, at various concentrations up to 20wt% of the mesoporous benzene-silica powder. The degree of sulphonation was 65% for sPEEK, and the ion-exchange capacity of mesoporous benzene-silica was 0.60mequiv./g. The mesoporous benzene-silica material had a 2D hexagonal (p6mm) mesostructure with a pore diameter of 2.7nm. The composite membranes exhibited higher proton conductivities than a pristine sPEEK membrane, and the proton conductivity increased with temperature. However, the sPEEK-based composite membranes showed very low methanol crossover below 5x10^-^7cm^2/s, but this value was still in the same range as the pristine sPEEK membrane. A maximum proton conductivity of 0.079S/cm was obtained for the sPEEK-OMB15 membrane at 80 deg.C, and the highest DMFC cell performance was at 56mW/cm^2, which were approximately 119 and 37% increases compared to the pristine sPEEK membrane, respectively. 39 refs.
Journal of Membrane Science, 351, No.1-2, 2010, p.58-64, ISSN: 0376-7388, DOI: 10.1016/j.memsci.2010.01.028
Cho E B; Luu D X; Kim D

1060260 - EFFECT OF MATRIX DUCTILITY ON ELASTIC-PLASTIC INTERLAMINAR STRESSES IN THERMOPLASTIC AS4/PEEK COMPOSITE LAMINATES
The effect of matrix plasticity on the free-edge effect in graphite fibre-reinforced PEEK thermoplastic composites under tensile loading was investigated using three orthotropic elastic finite element models with elastic and elastic-plastic PEEK resin-rich layers included. The non-linear tensile behaviour of the whole laminate was predicted and compared with experimental findings. It was found that the applicability of the models to elastic-plastic resin layer models was better in the lower loading case and that interlaminar stresses of various stacking sequence angle-ply laminates could be predicted using the models. 28 refs.
Journal of Reinforced Plastics and Composites, 29, No.5, 2010, p.741-754, ISSN: 0731-6844, DOI: 10.1177/0731684408100694
Min Shen; Jingwei Tong

1058795 - VICTREX PEEK AS LINING MATERIAL IN THE PROCESSING INDUSTRY (short article)
The use of Victrex PEEK as an alternative living and surface material in the processing industry is briefly discussed. The polymer is characterised by its combination of high chemical and temperature resistance, optimum wear properties, high mechanical strength and high purity compared with other materials. Victrex Polymer Solutions is also working on the development, production and application of PEEK-based pipes and tubes for the process industry.
Rubber Fibres Plastics International, 5, No.1, Jan.2010, p.12, ISSN: 1863-7116

1058263 - EFFECT OF CARBON NANOTUBES ON THE MECHANICAL PROPERTIES AND CRYSTALLIZATION BEHAVIOR OF POLY(ETHER ETHER KETONE)
Pristine carbon nanotubes (CNTs) and noncovalently functionalised carbon nanotubes (f-CNTs) were used to prepare poly(ether ether ketone) (PEEK) composites (CNTs/PEEK and f-CNTs/PEEK) via melt blending. Noncovalently functionalised multiwalled nanotubes were synthesised using hydrogen-bonding interactions between sulphonic groups of sulphonated poly(ether ether ketone) (SPEEK) and carboxylic groups of nanotubes treated by acid (CNTs-COOH). The effects of these two kinds of nanotubes on the mechanical properties and crystallisation behaviour of PEEK were investigated. CNTs improved mechanical properties and promoted the crystallisation rate of PEEK as a result of heterogeneous nucleation. Better enhancement of mechanical properties appeared in the f-CNTs/PEEK composites, which is ascribed to the good interaction between f-CNTs and PEEK. However, the strong interaction of f-CNTs and PEEK chains decreased the crystallisation rate of PEEK for high content of f-CNTs. 39 refs. Copyright (c) 2010 Elsevier Ltd.
Composites Science and Technology, 70, No.2, 2010, p.380-386, ISSN: 0266-3538, DOI: 10.1016/j.compscitech.2009.11.024
Rong C; Ma G; Zhang S; Song L; Chen Z; Wang G; Ajayan P M

1058174 - CROSS-LINKED POLY(ETHER ETHER KETONE) MEMBRANES WITH PENDANT SULFONIC ACID GROUPS FOR FUEL CELL APPLICATIONS
A series of cross-linkable poly(ether ether ketone)s (PEEKs) with pendant sulphonic acid groups were synthesised and used to prepare polymer electrolyte membranes for fuel cells. These transparent and flexible membranes are insoluble in common organic solvents and demonstrated little swelling in hot water. Thermal and mechanical stability of the membranes were evaluated using a thermogravimetric analyzer and strain-stress test, respectively. The methanol permeability of the cross-linked PEEKs with pendant sulphonic acid group membranes is much lower than that of Nafion 117 membrane, by more than 10 times. The conductivity of the cross-linked PEEK membrane with a 5% degree of cross-linking is comparable to that of Nafion 117 at 50 deg.C (0.053Scm^-^1) and even better above 80 deg.C. This kind of membrane is expected to be a good alternative to Nafion 117 in polymer electrolyte fuel cell applications. 25 refs.
Journal of Membrane Science, 348, No.1-2, 2010, p.319-325, ISSN: 0376-7388, DOI: 10.1016/j.memsci.2009.11.015
Zhou S; Kim J; Kim D

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