Thermal conductivity analysis TCA

Accurate thermal conductivity data are important in assessing the suitability of a particular polymer for a given application. It is also being used extensively in the application of computer modelling packages to predict the flow of plastics and rubber compoimds during processing operations. 

The ability to use modulated DSC to determine such data has already been mentioned (see Section 6.4.7). More traditional methods involve the use of the standard guarded hot plate device that is described in ASTM F-433. In addition to this, Lobo and Cohen [117] have described an in-line method that can be applied to polymer melts, and Oehmke and Wieg-mann [118] describe an apparatus that can perform thermal conductivity measurements as a function of temperature as well as pressure. 

The application of thermal analysis techniques to thermoplastics and rubbers is of major interest, being one of the principal uses for this group of analytical techniques, and imfortu-nately it has only been possible to give a brief overview within the confines of this chapter. It should be evident from the information that has been provided that for any polymer laboratory or facility to be fully effective, and provide a comprehensive service, it must possess as a minimum requirement at least the three thermal techniques that have been showcased here. 

This area of research and development is very active, with a healthy number of quality publications being produced each year from the many key workers in the field. The instrument mamrfactures have also continued to provide improvements in both the software and in the fundamental design of their instruments and their capability (e.g. modulated TGA and HyperDSC ). 

Another relatively recent innovation which is showing increasing promise and usefulness to researchers and contract analysts alike is the micro-TA technique. When combined with an atomic force microscope, the ability of this technique to provide topographical, DSC and DMA/TMA data on very small areas of a sample is proving invaluable in fundamental 

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