Mechanical stresses and charge stability in non-polar polymeric electrets

A correlation between morphology and charge stability in non-polar polymeric electrets has been studied. It has been possible to show that isometric heating of polymer led to the changes in the supermolecular structure, particularly in the crystallinity. Electret measurements were made using special experimental method, based on simultaneous registration of the thermal shrinkage stresses and the surface potential relaxation. It has been found that mechanical stresses in the polymer influenced on the charge stability significantly. From the results obtained we were able to determine the isometric heating conditions which were useful to improve charge stability of non-polar polymeric electrets