【作者】 周伟；

【导师】 俞炜；

【作者基本信息】 上海交通大学 ， 高分子化学与物理， 2010， 硕士

【摘要】 聚合物共混物的性能与其微观相形态结构和各组分的性能密切相关,而相形态又与各组分之间的相对含量和加工过程中经历的流场有关,因此研究相形态和流场特性对聚合物共混物流变性能的影响,有助于指导实际加工实践。现有的数学模型使人们能够将具有“海-岛”结构的聚合物共混物的流变特性和共混物的微观结构形态特性较好的关联起来;而对于具有“双连续”结构的共混物,现有的模型,如Veenstra模型,尽管在某些情况下能够得到与实验数据吻合的较好的实验结果,但是,由于它没有考虑到不相容聚合物之间界面张力的存在,采用此模型得到的拟合结果通常会低估共混物的动态模量。本文提出了一Veenstra模型的改进模型,使得线性粘弹性能和“双连续”共混物的结构信息相关联。“双连续”结构共混物的动态模量由组分和界面的贡献构成。界面的贡献,在共混物的流变行为中是最主要的,能够通过简化的“双连续”结构计算得到。通过模型结果与实验结果的对比,证明了“双连续”结构形态和线性粘弹性之间存在对应的联系。本文研究了典型的热力学不相容共混体系POE/PS,利用流变学和形态研究的方法,考察了不同相形态(“海-岛”结构和“双连续”结构)对聚合物反应共混过程的影响。研究发现相形态对聚合物原位增容共混反应有显著的影响,界面反应的进程与界面形态的变化能力直接相关。对于“双连续”结构的共混物,其形态稳定性最差,因而最有利于界面反应的发生;而在“海-岛”结构的共混体系中,界面反应的进程则取决于界面变形的难易程度,粘度比小的体系更容易发生界面反应。本文还考察了不同的流场强度及不同的共混时间对聚合物反应共混的影响。对于本文中的POE/PS/AlCl3体系,流场强度对该共混体系的最终产物的影响并不是很大,而流场强度对反应进程的影响则较大,较大的流场强度能够加快本文中体系的反应速率,使反应能够较快的达到平衡状态。更多还原

【Abstract】 It is an economical mean to manufacture polymer materials with desired properties through blending immiscible polymers. The performance of polymer blend has a deep affinity with the micro-structure and the components’ properties; the morphology also has a relation with the components’ relative content and the flow field while being processed. So it is of great importance to analysis the effect that how morphology and flow field can influence the blend’s rheological behavior.The mathematical model existent can perfectly correlate rheological behavior and microscopic structures of polymers blend which has a "sea-island" structure, while for a "co-continuous" structure, the existing models, such as Veenstra model, although in some cases can have a good fit with the experimental data, because it does not take into account the interfacial tension between the incompatible polymer, the fitted result obtained by this model usually underestimates the dynamic modulus of the blend. In this work, a rheological model is suggested to correlate the linear viscoelasticity and the structural information of "co-continuous" blends. The dynamic modulus of co-continuous blends is composed of the contribution from components and the interface. The interfacial contribution, which is most important in the rheology of blends, is calculated from a simplified "co-continuous" structure. This model has been compared with some experimental results, which proves a reasonable connection between the "co-continuous" structure and linear viscoelasticity of blends.By using the typical thermodynamic incompatible blending system POE/PS, the influence of different morphology ("sea-island" structure and "co-continuous" structure) on the polymer reactive blending processes was investigated by means of rheology and morphology analysis. It is found that phase morphology has a significant influence on the polymer reactive blending processes. Interfacial reactions happen more easily in blend with "co-continuous" morphology due to its weak stability, while in the blends with the "sea-island" morphology; the interface reaction process depends on the ease of interface deformation, which blends with small viscosity ratio favors interfacial reactions.The effect of different flow field intensity and blending time on the polymer reactive blending processes was also investigated. For the system in this article, the flow field has no obvious effect on the final reactive product, but has a significant effect on the reactive process. The larger flow field can accelerate the reactive rate, and make the reaction fast to reach equilibrium.更多还原