Mentor
JR Dennison & Allen Andersen
Document Type
Article
Publication Date
5-2018
First Page
1
Last Page
11
Abstract
The beta transition is a solid-state transition that occurs as part of the glass transition in amorphous polymers. The transition occurs at a temperature where above which the polymer is soft and rubbery and below the transition temperature the polymer is hard and brittle. The glass transition is thought to be caused by the increasingly coordinated movements of polymer chains as the temperature of the polymer increases. Once the temperature reaches the glass transition temperature, large scale motions of polymer chains occurs and there is a dramatic change in properties. In LDPE the glass transition occurs in the region between 230 K and 250 K [1,2].
Previous research done in the Materials Physics Group at Utah State University (USU) in radiation induced conductivity (RIC) and constant voltage conductivity (CVC) have seen abrupt changes in the temperature dependence of LDPE around the glass transition temperature [3,4]. Figure 1 also shows a graph created using data from electrostatic discharge (ESD) tests done on LDPE at various temperatures ranging from 150 K to 300 K [5]. In this graph it is easy to see that below around 240 K there exists a linearly increasing dependence on temperature, but above that temperature the breakdown field strength does not appear to significantly depend on temperature.
Recommended Citation
Tyler Kippen (with JR Dennison and Allen Andersen), "The Effects of the Beta Transition on Dielectric Breakdown in LDPE," Senior Thesis, Utah State University, Logan, UT, May 2018.