A computer automated thermal analysis laboratory for polymer characterization

Abstract

Thermal methods of analysis can be used to measure a wide variety of physical and chemical properties of polymer systems. These properties are usually determined by making one or more transformations of the output from the TA instruments. Transformations that are commonly encountered include multiplication, integration, differentiation, logarithms, baseline subtraction and combinations of these to fit complex equations. In many cases, the calculations and/or replotting require more time than the operation time of the instrument. This paper describes a software package that has been developed for use with a DEC PDP 11/40 computer system, which eliminates nearly all of the hand calculations and plotting that are normally encountered for DSC, TG, TMA and evolved gas techniques (TEA, TGC). The package consists of programs to perform direct data acquisition simultaneously from all the instruments, to transform the data as necessary, and to plot the TA curves in a form suitable for reporting. Substantial improvements in efficiency, accuracy and data analysis capabilities have been realized through automation of the TA laboratory. Specific examples of expanded capabilities for polymer characterization are described.