Temperature dependence of the shift factor for several polymers

Many bulk polymer properties have been well defined in the recent literature. In addition, theories that offer reasoning for changes in these bulk properties with temperature, pressure, etc. have been developed. Focus has been shifted in the past decade to polymers in thin film geometries. These systems remain obscure to polymer scientists. 

Thin films have become ubiquitous in the polymer industry. Fueled by the microelectronics industry and its need for miniature parts, polymer applications have become more demanding. Polymers in these environments have been tested and modeled in laboratories around the world from universities to automobile companies, research surrounding thin films is quickly growing.  

Two main areas of research have emerged that cover thin polymer films. The first, free-standing films, investigates thin films unattached to a substrate. The main concern in this field is how the air-polymer interface affects the behavior of the polymer as the film decreases in thickness. The second, polymer films on substrates, focuses on the interactions at the polymer-substrate interface. Both research fields have reported data and offered explanations for what has been observed. Although the second area is more relevant to the current research, the two interrelate, so the literature for each appears below. 

Although useful for modeling, most thin film applications are not free-standing, but confined to a substrate. These confined geometries present new challenges as the effects of more than one interface must be considered. 

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Figure 2.1-1 Temperature dependence of the shift factor for several polymers ...

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