Portal de Periódicos da CAPES

Two-step inflation of cellular polypropylene films: void-thickness increase and enhanced electromechanical properties

2004; Institute of Physics; Volume: 37; Issue: 4 Linguagem: Inglês

10.1088/0022-3727/37/4/013

1361-6463

Michael Wegener, Werner Wirges, Jens Fohlmeister, Brigitte Tiersch, Reimund Gerhard,

Polymer composites and self-healing

In cellular, electromechanically active polymer films, the so-called ferroelectrets, the cell size and shape distributions can be varied through a controlled inflation process. Up to now, high-pressure treatments were usually performed at elevated temperatures. There are, however, significant experimental limitations and complications if the pressure and temperature treatments are performed at the same time. Here, we demonstrate the controlled inflation of cellular polypropylene films by means of separate pressure and temperature treatments. Separate procedures are much easier to implement. Excellent electromechanical properties were achieved with such a two-step inflation process. The technique has significant potential for inflating large-area transducer films for electromechanical and electroacoustical applications.