【作者】 陈涛；

【导师】 王经文；

【作者基本信息】 南京航空航天大学 ， 材料加工工程， 2010， 硕士

【摘要】 电活性高分子是一类能在外加电场下实现电机转换功能的材料,在传感器、执行器及微电机体系具有广泛的应用。然而,其较低的介电常数是限制其应用的关键因素之一。铜酞菁齐聚物(CuPc)具有超高的介电常数,且其弹性模量低于陶瓷材料,与聚合物复合后,复合材料仍具有易于加工和柔韧性好等优点。本文采用湿法合成了CuPc,并为改善其与聚合物的相容性,将其化学接枝到聚对氯甲基苯乙烯(PCMS)的分子链上,得到PCMS-g-CuPc。然后采用溶液铸膜法制备了以CuPc和PCMS-g-CuPc为填料,聚氨酯弹性体( PU )为基体的两类复合材料( CuPc/PU和PCMS-g-CuPc/PU)。从TEM照片看出,PCMS-g-CuPc颗粒在基体中的分散性明显改善,而CuPc颗粒大小约为25nm,只有其在CuPc/PU中的尺寸的1/20。介电性能测试表明,CuPc的含量都为15wt%时,PCMS-g-CuPc/PU的介电常数达到将近350,约是CuPc/PU的7倍,且介电损耗有所降低。究其原因,主要是改性后的CuPc颗粒在基体中的尺寸大大减小和分散性大大改善显著地增强了复合材料的界面交换耦合效应所致。溶液铸膜法制备的复合薄膜底面存在聚合物沉淀,导致添加物在基体中分散不均匀,一定程度上降低了复合材料的介电性能。采用热压膜法对复合薄膜进行处理后,材料的介电性能得到了相应的提高。为了进一步提升复合材料的介电性能,本文还将CuPc直接接枝到PU分子链上得到PU-g-CuPc,并采用溶液铸膜法制备了以PU-g-CuPc为填料,PU为基体的PU-g-CuPc/PU复合薄膜。通过TEM观察发现改性后的CuPc在基体中的分散性大大改善,且其颗粒尺寸在10~20nm,较未改性的CuPc在基体中的颗粒尺寸的1/25还小,这也进一步增强了复合材料的界面交换耦合效应,进而提升了材料的介电性能。CuPc含量为15wt%时,PU-g-CuPc/PU的介电常数达到了440左右,是相同含量的CuPc/PU的介电常数的8倍多。更多还原

【Abstract】 Electroactive polymers (EAPs), which can realize electromechanical conversion under an external electric field, are attractive for a broad range of applications such as sensors, actuators and microelectromechanical systems. However, the low dielectric constant of a polymeric material is one of the key factors which limit the EAPs applications. Copper phthalocyanine oligomer (CuPc) has a very high dielectric constant and lower elastic modulus compared with ceramics. Therefore, when CuPc was incorporated in polymer matrix, the composite still take advantages like easy processing and good flexibility.In this thesis, CuPc was synthesized by solution method and successfully grafted with poly(p-chloromethyl styrene) (PCMS) (PCMS-g-CuPc) to improve the compatibility between the filler and the polyurethane (PU) matrix. Then, two kinds of composite films (CuPc/PU and PCMS-g-CuPc/PU) were prepared using solution cast method, and subsequently, hot-pressed technology. TEM morphologies reveal that the distribution of PCMS-g-CuPc in PU matrix was improved and CuPc particles were coated by PCMS with an average size of ca. 25nm, about 20 times smaller than that of CuPc in CuPc/PU. Both of the improvements remarkably enhanced the interface exchange coupling effect. As a result, the PCMS-g-CuPc/PU composite with 15wt% CuPc can realize a dielectric constant of ca. 350 at 100Hz, about 7 times larger than that of CuPc/PU, and the dielectric loss is relatively low. The dielectric constant enhancement of the hot-pressed films can be attributed to the elimination of the matrix deposition layer formed during the solution cast method and the homogeneous distribution of PCMS-g-CuPc in PU matrix. In order to further enhance the dielectric properties of the composites, CuPc was directly graftedonto PU chains (PU-g-CuPc) and PU-g-CuPc/PU composite films were prepared using solution cast method. According to the TEM morphologies, CuPc particles dispersed in PU matrix better and the size of CuPc particles is in the range of 10~20nm, which should further reinforce the interface exchange coupling effect. The dielectric constant of PU-g-CuPc/PU composite with 15wt% CuPc is ca. 440 at 100Hz, which is 8 times higher than that of CuPc/PU.更多还原