The strain-rate and temperature dependence of the mechanical properties of polyetherketone and polyetheretherketone

The mechanical properties of polyetheretherketone and polyetherketone were studied as a function of strain rate and temperature in the ranges 10−3 to 103s−1 and 20–200°C. At temperatures below the glass transition temperature, Tg, the strain-rate sensitivity of both polymers was found to be almost independent of temperature with a value of ∼4 MPa per decade of strain rate and the behaviour was well described by an Eyring relationship leading to an activation volume of ∼1 nm3. Above Tg, X-ray and differential scanning calorimetry studies show that cold-crystallization phenomena play a very important part in the polymer behaviour, leading to an increase of yield stress with increasing temperature. The crystallization was found to be highly strain-rate dependent with no increase in crystalline content occurring in quasi-static tests and increases of up to 20% in higher rate tests. Much of the data have been gathered using novel test equipment which is described in the paper.

[1]  D. J. Blundell,et al.  Polymer reportX-ray data for poly(aryl ether ketones) , 1980 .

[2]  J. Seferis,et al.  Heat transfer effects on the processing‐structure relationships of polyetheretherketone (PEEK) based composites , 1988 .

[3]  N. Schneider,et al.  Effects of mechanical drawing on the structure and properties of peek , 1988 .

[4]  J. Field,et al.  A study of the rapid deformation behaviour of a range of polymers , 1989, Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences.

[5]  P. R. Pinnock,et al.  The mechanical properties of solid polymers , 1966 .

[6]  D. J. Blundell,et al.  The morphology of poly(aryl-ether-ether-ketone) , 1983 .

[7]  J. Rose,et al.  Synthesis and properties of polyaryletherketones , 1981 .

[8]  B. Crossland,et al.  Mechanical Properties at High Rates of Strain , 1976 .

[9]  Stephen Z. D. Cheng,et al.  Glass transition and melting behavior of poly(oxy-1,4-phenyleneoxy-1,4-phenylenecarbonyl-1,4-phenylene) (PEEK) , 1986 .

[10]  M. Sahota,et al.  Structural order in alkali-degraded PAN as seen in studies of low-temperature thermal conductivity , 1983 .

[11]  P. Cebe,et al.  Crystallization behaviour of poly(ether-ether-ketone) , 1986 .

[12]  D. J. Blundell.  On the interpretation of multiple melting peaks in poly(ether ether ketone) , 1987 .

[13]  I. Ward,et al.  Polymer communications: X-ray diffraction study of die drawn poly (aryletherketone) (PEEK) , 1983 .

[14]  I. H. Hall.  The effect of strain rate on the stress–strain curve of oriented polymers. II. The influence of heat developed during extension , 1968 .