THE STRUCTURE AND MECHANICAL-PROPERTIES OF SHEETS PREPARED FROM BACTERIAL CELLULOSE .2. IMPROVEMENT OF THE MECHANICAL-PROPERTIES OF SHEETS AND THEIR APPLICABILITY TO DIAPHRAGMS OF ELECTROACOUSTIC TRANSDUCERS

A sheet obtained from bacterial cellulose had a remarkably high modulus of elasticity as reported in Part 1 of this series. The Young's modulus of a sheet prepared by squeezing and drying a gel-like pellicle of bacterial cellulose was found to be > 15 G Pa. In addition, it has been found that treatment of the gel-like pellicles or dried sheets of bacterial cellulose with alkaline and/or oxidative solutions improves the mechanical properties significantly, and the Young's modulus of the resulting sheets approaches 30 G Pa. In this paper, improvement of the mechanical properties of bacterial cellulose sheets by the removal of impurities is investigated and the applicability of bacterial cellulose to diaphragms of electroacoustic transducers is discussed. © 1990 Chapman and Hall Ltd.