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Structure and electromechanical properties of cellulose derivatives with electrical function

具有电功能的纤维素衍生物的结构和机电性能

基本信息

批准号：
09660178
负责人：
HIRAI Nobuyuki
金额：
$ 2.11万
依托单位：
Shizuoka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

项目摘要

The purpose of the present investigation is to develop electrically functional and environmentally friendly materials from cellulose derivatieves. The piezoelectricity of CEHEC were investigated.The results obtained were summarized as follows.1) Dependence of the piezoelectric, dielectric, and elastic constants on temperature was measured. Elastic, piezoelectric, and dielectric relaxations were observed between -80℃ and -60℃ and elastic and piezoelectric relaxations between 0℃ and 20℃ at a frequency of 10 Hz. The activation energies are about 9-15 kcal/mol in the low-temperature region and about 30-45 kcal/mol in the higher temperature region. These relaxations may be caused by the motion of the cyanoethyl group at low temperature and mostly by motions of the main chain at room temperature.2) Relationships between degree of substitution and values of the dielectric, elastic and piezoelectric moduli were investigated. With increase of degree of substitution by cyano group, the values of … More the dielectric, elastic and piezoelectric moduli of CEHEC increased.3) At room temperature CEHEC has a large piezoelectric constant, approximately 10ィイD1-11ィエD1 C/N, which is similar to the constant for polyvinylidene fluoride. The high level of piezoelectricity of CEHEC may be related to the orientation of the molecular chains with the polar cyano group during streching.4) The electromechanical coupling factor for CEHEC was small(4%). Dynamic moduli were measured by vibrating reed method in cases of which electric field E is zero and electric displacement D is constant. It was recognized that the value of dynamic modulus at the case of which D is constant is large compared with that of E=0. Also in the case of tangent loss tan δ, there was observed the difference between the case of D=const and E=0.5) The elastic constant of CEHEC film reduced slowly with increasing duration of the treatment in soil. It is recognaized that biodegradation takes place first with decrease of degree of substitution of cyano group and CEHEC film can be degraded by microorganisms in soil. Less

本研究的目的是从纤维素衍生物中开发电功能和环境友好的材料。研究了CEHEC的压电性，主要结果如下：1）测定了CEHEC的压电常数、介电常数和弹性常数随温度的变化关系。在10 Hz的频率下，在-80℃和-60℃之间观察到弹性、压电和介电弛豫，在0℃和20℃之间观察到弹性和压电弛豫。活化能在低温区约为9-15千卡/摩尔，在高温区约为30-45千卡/摩尔。这些弛豫在低温下可能是由氰乙基基团的运动引起的，在室温下主要是由主链的运动引起的。2）研究了取代度与介电、弹性和压电模量之间的关系。随着氰基取代度的增加， ...更多信息 CEHEC的介电模量、弹性模量和压电模量均有所提高。3）室温下，CEHEC具有较大的压电常数，约为10 Ω·D 1 -11 Ω·D 1 C/N，与聚偏氟乙烯的压电常数相近。CEHEC的高压电性可能与其极性氰基分子链在拉伸过程中的取向有关。4）CEHEC的机电耦合系数较小（4%）。在电场E为零，电位移D为常数的情况下，用振簧法测量了材料的动态模量。可以认识到，与E=0的情况相比，D为常数的情况下的动态模量的值大。此外，在切向损耗tan δ的情况下，观察到D=const和E=0.5的情况之间存在差异）CEHEC膜的弹性常数随着土壤处理时间的增加而缓慢降低。结果表明，随着氰基取代度的降低，CEHEC膜的生物降解作用首先发生，CEHEC膜在土壤中可被微生物降解。少