Title :
Optimization of piezoelectric properties of cellular polypropylene films by repeated expansion
Author :
Zhang, Xiaoqing ; Sessler, Gerhard M. ; Hillenbrand, Joachim
Author_Institution :
Inst. for Commun. Technol., Darmstadt Univ. of Technol., Germany
Abstract :
The piezoelectric d33-coefficients of customary cellular polypropylene (PP) films can be significantly improved by a double-expansion process. In the present paper, the experimental procedure is described and experimental results of d33-coefficients that can be achieved by choosing expansion pressures of 2 MPa and a range of expansion temperatures up to 120°C for the two expansion processes are discussed. For example, a temperature of 90 to 100°C for the first expansion and 60°C for the second expansion, and exposure times of the order of 1 h result in stable quasistatic d33-coefficients of more than 1000 pC/N.
Keywords :
piezoelectricity; polymer films; 1 h; 2 MPa; 60 C; 90 to 100 C; cellular polypropylene films; double-expansion process; optimization; piezoelectric coefficients; quasistatic d33-coefficients; Biological materials; Communications technology; Corona; Metallization; Needles; Physics; Piezoelectric films; Solid state circuits; Temperature dependence; Temperature distribution;
Conference_Titel :
Electrets, 2005. ISE-12. 2005 12th International Symposium on
Print_ISBN :
0-7803-9116-0
DOI :
10.1109/ISE.2005.1612316