TY - JOUR
T1 - Physical properties of poly(ether ether ketone) exposed to simulated severe oilfield service conditions
AU - Mohammed, Musarrat H.
AU - Banks, William M.
AU - Hayward, David
AU - Liggat, John J.
AU - Pethrick, Richard A.
AU - Thomson, Barry
N1 - NOTICE: this is the author’s version of a work that was accepted for publication in Polymer Degradation and Stability. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Polymer Degradation and Stability, [VOL 98, ISSUE 6, (1/6/13)] DOI: 10.1016/j.polymdegradstab.2013.02.014
PY - 2013/6
Y1 - 2013/6
N2 - The property changes occurring when poly(ether ether ketone) (PEEK) is subject to methane and carbon dioxide at high pressures (108 Pa) and high temperatures (175-200 °C) are reported. Differential scanning calorimetry, density gradient techniques, positron annihilation lifetime spectroscopy, dynamic mechanical thermal analysis and tensile tests measurements were used to monitor the changes which occur during the ageing process. Over the period of the study an overall increase in the tensile strength was noted, with little or no change in 0.2% and 2% proof stresses, whilst there was a decrease in bending modulus and glass transition temperature due to the effects of plasticization. The Young's modulus generally increases for samples exposed to a temperature of 175 °C in the presence of a mixture of 90% methane and 10% carbon dioxide, or carbon dioxide alone, but it decreases at 200 degrees C in the presence of carbon dioxide alone. The observed effects are consistent with the polymer undergoing initially a densification of the matrix associated with annealing-induced crystallisation, followed by plasticization as the gases permeate into the disordered regions of the matrix. When de-pressurised, the gas dissolved in the matrix attempts to leave the matrix and morphological changes are observed. The complexity of the changes in crystallinity and plasticization in the disordered phase are reflected in changes in the positron annihilation data.
AB - The property changes occurring when poly(ether ether ketone) (PEEK) is subject to methane and carbon dioxide at high pressures (108 Pa) and high temperatures (175-200 °C) are reported. Differential scanning calorimetry, density gradient techniques, positron annihilation lifetime spectroscopy, dynamic mechanical thermal analysis and tensile tests measurements were used to monitor the changes which occur during the ageing process. Over the period of the study an overall increase in the tensile strength was noted, with little or no change in 0.2% and 2% proof stresses, whilst there was a decrease in bending modulus and glass transition temperature due to the effects of plasticization. The Young's modulus generally increases for samples exposed to a temperature of 175 °C in the presence of a mixture of 90% methane and 10% carbon dioxide, or carbon dioxide alone, but it decreases at 200 degrees C in the presence of carbon dioxide alone. The observed effects are consistent with the polymer undergoing initially a densification of the matrix associated with annealing-induced crystallisation, followed by plasticization as the gases permeate into the disordered regions of the matrix. When de-pressurised, the gas dissolved in the matrix attempts to leave the matrix and morphological changes are observed. The complexity of the changes in crystallinity and plasticization in the disordered phase are reflected in changes in the positron annihilation data.
KW - positron annihilation
KW - dynamic mechanical thermal analysis
KW - differential scanning calorimery
KW - PEEK, poly(ether ether ketone)
KW - methane
KW - carbon dioxide
KW - spectroscopy
KW - transport properties
KW - crystal morphology
KW - polymers
KW - degradation
KW - blends
UR - http://www.scopus.com/inward/record.url?scp=84876891628&partnerID=8YFLogxK
UR - http://www.sciencedirect.com/science/article/pii/S0141391013000499
U2 - 10.1016/j.polymdegradstab.2013.02.014
DO - 10.1016/j.polymdegradstab.2013.02.014
M3 - Article
VL - 98
SP - 1264
EP - 1270
JO - Polymer Degradation and Stability
JF - Polymer Degradation and Stability
SN - 0141-3910
IS - 6
ER -