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。并对纤维素衍生物的铁电性进行了探讨。在纤维素衍生物中，氰基化纤维素具有最高的压电模量。所得结果总结如下：1。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氢氧乙基纤维素的压电模量。在20‰的温度下，氰乙基羟乙基纤维素的值约为1-2 × 10^<-11> C/N。它的价值是纤维素衍生物中最高的，接近聚乙烯醇氟的价值。通过提高压电极化率，有可能将其作为具有电功能的工业材料。对具有高压电模量的氰乙基化氢氧乙基纤维素进行了铁电性纤维素衍生物d（电位移）-E（电场）磁滞回线的可能性测量。但我们无法通过实验证明氰乙基羟乙基纤维素中铁电性的存在。由于直流电流增大，试样不能施加高电场。必须去除离子和其他低分子量杂质。高拉伸取向或极性侧链以强电场或强磁场取向的纤维素衍生物的铁电性测量目前正在考虑中。

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.