Structure and Properties of Cellulose Derivatives with Piezoelectricity, Pyroelectricity and Ferroelectricity

本研究的目的是开发纤维素衍生物的高压电材料。并探讨了纤维素衍生物具有铁电性的可能性。在纤维素衍生物中，氰乙基化纤维素具有最高的压电模量.具有高压电模量的纤维素衍生物测定了硝酸纤维素、醋酸纤维素、氰乙基化纤维素和氰乙基化羟乙基纤维素的压电模量。氰乙基化羟乙基纤维素在20 ℃时的值约为1- 2x 10 ^<-11>C/N。其值在纤维素衍生物中最高，接近聚氟乙烯的值。通过提高压电陶瓷的压电陶瓷化程度，有可能将其作为具有电功能的工业材料.测定了具有高压电模量的氰乙基化羟乙基纤维素的电滞回线。但我们无法实验证明氰乙基化羟乙基纤维素中存在铁电性。由于直流电流的增加，高电场不能施加到试样上。必须除去离子和其它低分子量杂质。目前正在考虑对纤维素衍生物的铁电性进行测量，这些纤维素衍生物是通过高拉伸取向的，或者其极性侧链是通过高电场或高磁场取向的。

The purpose of the present investigation is to develop the high piezoelectric materials of cellulose derivatives. And also the possibility of ferroelectricity of cellulose derivatives has been studied. It is recognized that cyanoethylated cellulose has the highest piezoelectric modulus in the cellulose derivatives.The results obtained are summarized as follows.1. Cellulose derivatives with high piezoelectric modulusThe piezoelectric modulu of cellulose nitrate, cellulose acetate, cyanoethylated cellulose and cyanoethylated hydoroxyethylcellulose have been measured. The value of cyanoethylated hydroxyethylcellulose is about 1-2x10^<-11> C/N at 20ﾟC.The value of it is the highest in the cellulose derivatives and is approaching the value of Polyvinyl fluoride. It may be possible to use it as industrial materials with electric functions by increasing the piezoelectric porlarization.2. Possibility of ferroelectric cellulose derivativesD(electric displasement)-E(electric field) hysteresis loop is measured about the cyanoethylated hidroxyethylcellulose whith high piezoelectric modulus. But we could not experimentally prove the existence of ferroelectricity in cyanoethylated hydroxyethylcellulose. Because of increasement of direct current, high electric field could not be applied to the specimens. It is necessary to remove ionic and other low molecular weight impurities. Measurements of ferroelectricity of cellulose derivatives which are oriented by high drawing, or of which polar side chains are oriented by high electric field or high magnetic field are now under consideration.