【作者】 高琳；

【导师】 刘立柱；

【作者基本信息】 哈尔滨理工大学 ， 高分子化学与物理， 2008， 硕士

【摘要】 本文以均苯四甲酸二酐（PMDA）及4, 4’-二氨基二苯基醚（ODA）为原料,N, N-二甲基乙酰胺（DMAc）为溶剂经逐步缩聚反应制备聚酰胺酸（PAA）,采用机械共混法将经硅烷偶联剂改性的纳米Al₂O₃粉体,借助超声波以一定的方式加入到PAA中,经热亚胺化成功制备了多个系列聚酰亚胺（PI）/纳米Al₂O₃杂化薄膜。采用扫描电子显微镜和X-射线衍射表征了PI杂化薄膜的微观形貌和聚酰亚胺分子链的有序度,测试了系列PI杂化薄膜的紫外-可见光透过率、热稳定性、力学性能和电击穿场强。扫描电镜分析表明纳米Al₂O₃的晶型和含量以及硅烷偶联剂的种类和用量对PI杂化薄膜中纳米Al₂O₃的分散状态有较大影响。X-射线衍射、紫外-可见光透过率分析表明纳米Al₂O₃的晶型和含量以及硅烷偶联剂的种类对聚酰亚胺分子链的有序度、紫外-可见光透过率的影响较大,而偶联剂的用量对其影响较小。热失重测试、力学性能测试、电击穿场强测试分析表明PI纳米杂化薄膜的热分解温度、电击穿场强均高于纯PI膜,而力学性能低于纯PI膜,掺杂γ-Al₂O₃的PI杂化薄膜的热稳定性、拉伸强度高于掺杂α-Al₂O₃的PI杂化薄膜;掺杂α-Al₂O₃的PI杂化薄膜的电击穿场强高于掺杂γ-Al₂O₃的PI杂化薄膜;在使用四种偶联剂改性α-Al₂O₃制备的PI杂化薄膜中,使用硅烷偶联剂KH-550的PI杂化薄膜的热稳定性、力学性能最好,使用硅烷偶联剂AE3012的PI杂化薄膜电击穿场强最高,当偶联剂AE3012用量为无机粒子质量分数的4wt%时,该杂化薄膜的热稳定性、力学性能、电击穿场强均最好。更多还原

【Abstract】 In this paper, poly（amic acid） was synthesized by step-polycondensation of 4,4’-oxydianiline（ODA） and pyromellitic dianhydride（PMDA）in the solution of N,N-dimethylacetamide（DMAc）. Many series of polyimide/nano-Al₂O₃ hybrid films were prepared by the addition of the nano-Al₂O₃ which has been treated by coupling agent into the poly（amic acid） solution by ultrasonic wave through the ultrasonic-mechanical method and thermal imiditation.The micro-morphology of PI hybrid films and degree of order of polyimide molecular were studied by SEM and spectra of X-ray diffraction. Transmittivity of UV-Vis, thermal stability, mechanical properties and breakdown strength of PI hybrid films were tested. SEM analysis showed that the contents and crystallographic of nano-Al₂O₃ and the species and amount of silane coupling agents had much effect on the dispersion of nano-Al₂O₃ particles in the PI hybrid films. Spectra of X-ray diffraction and UV-Vis transmittance analysis showed that the contents and crystallographic of nano-Al₂O₃ and the species of silane coupling agents had much effect on the degree of order of polyimide molecular and transmittance of UV-Vis of PI hybrid films, but the content of silane coupling agent had less effect on them. TGA, mechanical and breakdown strength analysis showed thermal stability and breakdown strength of PI/nano-Al₂O₃ hybrid films were higher than pure PI film, but mechanical properties of PI/nano-Al₂O₃ hybrid films were lower than that of pure PI film. Thermal stability and tensile strength of PI hybrid films withγ-Al₂O₃ is higher thanα-Al₂O₃; in the PI/nano-Al₂O₃ hybrid films, the nano-Al₂O₃ was treated by four kinds of coupling agent, thermal stability and mechanical properties of PI hybrid films with KH550 were the best; breakdown strength of PI hybrid films with AE3012 was the highest; when silane coupling agent AE3012 is 4wt% of mass percent of inorganic particles during modifying treatment, thermal stability , mechanical properties and breakdown strength of PI hybrid films were the best.更多还原