论文总字数：23562字

摘 要

压电材料是一类可以将压强、振动等应力/应变迅速转变为电信号，或将电信号转变为形变、振动等信号的机电耦合的功能材料，广泛应用于振荡器、转换器、护目镜、声呐等器件。传统的铅基压电材料中含铅量较高、硬度大、不易加工，同时给生态环境带来了严重危害，基于对环境的保护和实际应用的需求，开发出具有优异柔韧性、机械性和可加工性的柔性压电薄膜材料具有重要的意义。近年来，聚偏氟乙烯(Polyvinylidene flouride, PVDF)基压电复合材料因韧度高、生物兼容性好等优点，获得了科研人员的青睐。但其介电常数和压电常数较低，将功能粒子掺杂到PVDF基体中来获得具有高压电性能复合材料是目前的研究热点。本论文以PVDF作为聚合物基体，选择1H，1H，2H，2H-全氟辛基三乙氧基硅烷(pots)接枝磺基芳纶(s-PPTA)作为压电纳米团簇，两者共混制备了全有机压电复合薄膜材料，并研究了其压电性能以及压电粒子的作用机理。

通过水溶液聚合制备了PPTA-pots压电纳米团簇，经退火处理和极化处理后制备PVDF/PPTA@pots压电复合薄膜。利用FTIR、XRD、SEM以及压电性能测试等技术对PVDF/PPTA@pots压电复合薄膜进行表征测试。研究结果表明：在PVDF压电复合材料中，PPTA-pots纳米团簇被包裹在PVDF聚合物基体中，有利于形成晶核，促进结晶作用，提升PVDF的β相，使PVDF压电复合材料的压电性能得到提升。

最后，在对PVDF/PPTA@pots压电复合薄膜性能研究过程中发现了制备薄膜的压电性能还有待进一步提升、薄膜电流输出信号不稳定的问题。针对这两个问题，文章给出了几点可行性方案：采用单轴拉伸PVDF、探究最适宜PPTA-pots纳米团簇含量、探究复合材料压电性能最优异时的纳米团簇支化度以及采用静电纺丝法制备PVDF/PPTA@pots压电复合薄膜等几个研究方向，进一步提升压电复合薄膜的压电性能。

关键词：聚偏氟乙烯；复合材料；聚对苯二甲酰对苯胺；压电性能

Abstract

Piezoelectric materials are a kind of functional materials that can quickly convert stress/strain such as pressure and vibration into electrical signals, or electrical signals into mechanical and electrical coupling of deformation and vibration signals. They are widely used in oscillator, converter, goggles, sonar and other devices.In the traditional lead-based piezoelectric materials, the lead content is high, the hardness is large, it is difficult to process, and it also brings serious harm to the ecological environment. Based on the environmental protection and practical application requirements, it is of great significance to develop a flexible piezoelectric film material with excellent flexibility, mechanics and machinability.In recent years, Polyvinylidene flouride (PVDF) -based piezoelectric composites have been favored by researchers due to their high toughness and good biological compatibility. However, its dielectric constant and piezoelectric constant are relatively low, so it is a hot research topic to doped functional particles into PVDF matrix to obtain composite materials with high piezoelectric properties.In this paper, PVDF was used as the polymer matrix, and pots(1H, 1H, 2H, 2H-perfluorooctyl triethoxysilane) was grafted onto s-ppta(sulfonic aramid) as the piezoelectric nanoclusters. The composite organic piezoelectric films were prepared by mixing them, and the piezoelectric properties and the mechanism of piezoelectric particles were studied.

PPTA-pots piezoelectric nano clusters were prepared by aqueous solution polymerization.PVDF/PPTA@pots piezoelectric composite films were prepared by annealing and polarization treatment. The PVDF/PPTA@pots piezoelectric composite films had been characterized by FTIR, XRD, SEM and piezoelectric performance test. The results showed that: in PVDF piezoelectric composite material, the piezoelectric nano clusters are wrapped in the PVDF polymer matrix, which is conducive to the formation of crystal nuclei, promoting the crystallization, improving the β phase of PVDF, and improving the piezoelectric performance of PVDF piezoelectric composite material.

Finally, in the process of studying the properties of PVDF/ ppta@pots piezoelectric composite film, it is found that the piezoelectric properties of the prepared film need to be further improved and the current output signal of the film is not stable.In order to solve these two problems, several feasible schemes are proposed: using uniaxial tension PVDF, exploring the optimal ppta-pots nanocluster content, exploring the branching degree of nanoclusters when the piezoelectric properties of composite materials are the best, and preparing PVDF/ ppta@pots piezoelectric composite films by electrostatic spinning.

Key Words：Polyvinylidene fluoride；Composites materials；Poly-p-phenylene terphthamide；Piezoelectric properties

目 录

第1章 绪论 1

• 1. 压电材料简介 1

1.1.1 压电单晶 1

1.1.2 压电陶瓷 1

1.1.3压电聚合物 2

1.1.4压电复合材料 2

• 1. PVDF以及PVDF薄膜 2

1.2.1 PVDF晶体结构 2

1.2.2 PVDF晶相转变 3

1.2.3 PVDF薄膜的制备方法 4

• 1. PVDF压电复合材料研究现状 7
  2. 选题意义和研究内容 8

第2章 PVDF/PPTA@pot压电薄膜的制备与性能研究 9

2.1 材料与实验 9

2.1.1 实验药品 9

2.1.2 实验设备与仪器 9

2.1.3 实验步骤 9

2.2 材料结构表征与压电性能研究 10

2.2.1 PVDF/PPTA@pots晶相结构分析 10

2.2.2 PVDF/PPTA@pots结晶结构分析 12

2.2.3 PVDF/PPTA@pots微观形貌分析 13

2.2.4 PVDF/PPTA@pots压电复合薄膜的压电性能分析 14

2.3 本章小结 15

第3章 PVDF/PPTA@pot压电复合薄膜可行性方案 17

3.1 提升PVDF/PPTA@pot压电复合薄膜的压电性能 17

3.1.1 单轴拉伸 17

3.1.2 PVDF压电复合薄膜中压电纳米团簇含量 17

3.1.3 压电纳米团簇的支化度 18

3.2 提升PVDF/PPTA@pot压电复合薄膜的电流输出稳定性 19

3.3 本章小结 19

第4章 结论 21

参考文献 22

致谢 25

第1章 绪论

压电材料是一种机电耦合功能材料，它能快速地将压力、转动、振动等信号转化为电信号。压电机理是指当压电晶体的对称性很低时，施加外力使压电晶体产生形变，此时晶胞内正、负离子的相对位移将会导致其内部的正、负电荷中心不再重合，从而产生宏观极化，因此，压电材料受到压力作用时，在两个受力端面上会同时出现异号电荷。1880年，Pierre和Jacques在石英中发现了正向压电效应，1881年Gabriel发现了逆向压电效应^[1-2]。自此人们开始密切关注压电材料并深入研究，压电材料也得以广泛应用于振荡器、转换器、护目镜、声呐等领域。

1.1 压电材料简介

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