Study Of Piezoelectric Damping Composites By Base With Chlorobutyl Rubber

The thesis is the project supported by NSAF presided by adviser (No.10276031).The intention of this thesis focuses on how to develop a high property damping materials by base with butyl rubber based on energy transitions mechanism of piezoelectricity-Joule's law and the conventional friction damping provided by rubber. The traditional mechanical damping mechanism is broken through with the use of nano materials.The new type of damping composites is consisted of chlorobutyl rubber, piezoelectric ceramic powder (PZT) and acetylene black. Except for traditional damping mechanism of chlorobutyl rubber, mechanical vibration energy can be changed into electric energy induced by piezoelectric ceramic's piezoelectric effect, and then the energy can be dissipated in form of Joule's heat through conductive micro-circuit formed by conductive fillers in the system. It is particular investigated on damping mechanism of the composites and the influence of the proportion and technics on the performance is analyzed.The dynamic mechanical properties of the composites have been studied. The results show that the value of loss factor (tan δ ) of materials that the NSAF project prescribes is filled or is exceeded. Moreover, the temperature area with tan 8 not less than 0.7 is twice of the prescribed area. With use of nano and sub-nano materials, it is solved that piezoelectric ceramic powder is difficult to be compounded with rubbers due to the difference of mechanical modulus. The damping mechanism that piezoelectric effect-Joule's law and the traditional friction damping are used together in bulk materials is a great breakthrough in theory, which provides a new approach for research of novel materials.