Victrex (United Kingdom)

Driven by the need to make high temperature thermoplastic polymers more processable and expand the range of applications, this study reports on the properties of a novel PAEK material developed by Victrex (Thornton Cleveleys, UK) which is capable of undergoing crosslinking or crystallisation, two competing processes that can be adapted via specific processing temperature and time conditions. The uniqueness of this PAEK material resides in its manufacturing approach, where the crosslinkers are incorporated during the polymerisation process, and its distinct properties, including a controllable viscosity that can be tuned from low to high to allow its application in complex manufacturing processes, such as thermoplastic carbon fibre manufacturing.

Interpretation of resistivity measurements is often uncertain as resistivity is controlled by pore fluid chemistry, moisture content and lithology. Geophysicists currently must rely on the availability of site information to reduce this uncertainty. Induced polarization (IP) measurements may help to reduce this uncertainty as they are primarily controlled by lithology and, relative to resistivity measurements, weakly dependent on pore fluid chemistry. In order to exploit this potential, we have investigated the relationship between the surface conductivity appearing in petrophysical models for resistivity and the imaginary conductivity measured with induced polarization. It has previously been suggested that imaginary conductivity can be used to estimate the surface conductivity if the ratio of surface polarization to surface conduction (l) is known. However, a detailed investigation of this ratio has not hitherto been reported. We performed a study on an extensive database of sandstone and unconsolidated samples where resistivity and induced polarization measurements were acquired as a function of salinity. The surface conductivity was estimated assuming a simple parallel conduction model where conduction through interconnected pores and conduction along interconnected pore surfaces add in parallel. The surface conductivity exhibits a weak salinity dependence that is similar in shape to the salinity dependence of the imaginary conductivity. This finding suggests that l is only weakly dependent on salinity. The existence of a relationship between the surface conductivity and the imaginary conductivity measured with IP may pave the way towards more reliable petrophysical relations. For example, it is usually not possible to estimate the formation factor from a single measurement of resistivity at a known salinity due to the unknown influence of surface conductivity. Our findings suggest that IP data could constrain the magnitude of the surface conductivity and therefore result in reliable formation factor estimation.

The electronics industry is moving from lead-based solder systems to lead-free solder systems. This change increases the processing temperatures used to melt and flow the new lead-free solders. This is causing many of the traditional polymeric materials used for electronic components to fail. Therefore, the polymers with high temperature resistance, such as VICTREXreg PEEK (poly (aryl ether ether ketone)) polymer, are getting very important in the manufacturing processes using lead-free solders. In this paper, the performance of PEEK polymer and other plastic materials are presented from a lead-free soldering process viewpoint. This paper also describes some applications in which PEEK polymer has been successfully applied, including mobile phone secondary battery gaskets, speaker diaphragms, connectors, and so on.

Radicals, derived from the ozonates of alkenes, have been shown to be capable of initiating polymerisations of methyl methacrylate, styrene and vinyl acetate: in the case of styrene polymerisations the molar masses obtained at low conversion did not follow the expected trend with temperature.