【作者】 王秉晖；

【导师】 杨小平；

【作者基本信息】 北京化工大学 ， 材料学， 2009， 硕士

【摘要】 由于微观结构对材料的力学性能存在着显著的影响,为了使材料获得最佳的使用性能,需要探索最佳的制备方法及工艺条件以获得有利于提高材料性能的结构。本课题通过对改性体系相分离的历程进行观察和表征,分析和探讨增韧体系固化过程以及相分离过程,其研究结果为进一步发展纳米纤维增韧碳纤维树脂基复合材料提供了基础数据。通过同步辐射小角X光散射研究了聚砜纳米纤维膜增韧环氧树脂的反应诱导相分离,并采用相差显微镜,扫描电子显微镜等其他方法进行佐证。结果表明:该体系的相分离过程遵循的是成核-生长机理,形成海岛结构并且还是“原位”相分离,相分离后的聚砜微球沿着纳米纤维的“痕迹”有序排列。采用差示扫描量热法(DSC)和近红外光谱(NIR)研究了环氧树脂基体、5 wt%聚砜纳米纤维膜和溶剂法膜增韧环氧树脂的等温固化反应动力学。结果表明:随着聚砜的加入并没有改变固化机理和反应级数。在固化反应初期,聚砜纳米纤维膜增韧体系的反应速率高于溶剂法膜增韧体系和树脂基体,而聚砜纳米纤维膜和溶剂法膜增韧体系的最终转化率却低于树脂基体。而且在固化反应过程中,一级胺在凝胶点之前基本消耗殆尽。更多还原

【Abstract】 Because of the prominent effect by microstructure on mechanical capabilities, we need to explore a best way of preparation and most appropriate technics condition to obtain structures which are propitious to advance material capability. The results provide basic data in the development of carbonfibre composites toughened by nanofibre.The process on the reaction-induced phase separation of PSF nanofibrous membranes toughened epoxy resin was studied by phase contrast microscope, scanning electron microscope and synchrotron radiation small angle X-ray scattering ( SR-SAXS). Results showed that phase separation was induced by nucleation and growing mechanism, exhibiting sea-island morphology. And PSF spheres were aligned randomly along nanofibers direction, which was attributed to in-situ phase separation of PSF.The isothermal curing kinetics of epoxy matrix, 5 wt % PSF nanofibrous membranes and films toughened epoxy resins were investigated by Differential Scanning Caliorimetry (DSC) and Near Infra-red Spectroscopy (NIR). The fundamental kinetic parameters were compared, and the conversion of epoxide group and the curing rate exhibited identical variations. At the initial curing stage, the curing rate of PSF nanofibrous membranes toughened epoxy resin was faster than that of PSF films toughened epoxy resin and epoxy matrix, whereas the final conversion degree of PSF nanofibrous membranes and films toughened epoxy resins was lower than that of epoxy matrix. The curing mechanism could be explained by the variation of primary amine from NIR testing.更多还原