水辅混炼挤出促进纳米粒子分散的研究

发布时间：2018-02-27 22:38

本文关键词： 水辅混炼挤出间歇法发泡埃洛石纳米管氧化石墨烯微观结构流变性能力学性能热稳定性　出处：《华南理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：聚合物基纳米复合材料和微孔发泡聚合物材料的高性能制备和结构调控越来越多地得到工业界和学术界的重视。本学位论文采用水辅混炼挤出和间歇法发泡展开相关研究。首先,基于水辅混炼的作用机理,构建水辅混炼挤出实验设备;其次,采用水辅混炼挤出制备聚丙烯/埃洛石纳米管(PP/HNTs)和聚偏氟乙烯/氧化石墨烯(PVDF/GO)复合材料,探索水促进纳米粒子分散的机理;最后,对水辅混炼挤出制备的部分PP/HNTs和PVDF/GO纳米复合材料以及普通挤出制备的PP/乙烯辛烯共聚物(POE)共混物进行发泡。采用水辅混炼挤出制备PP/HNTs 85/15复合材料。结果表明,随注水量增加,HNTs在PP基体中的分散趋于均匀;当注水量为2 L/h时,HNTs均匀地分散和分布在PP基体中。这表明在混炼过程中,水呈现的塑化、汽化和局部膨胀效应,对HNTs的分散有明显促进作用。HNTs的均匀分散,可提高复合材料的储能模量、复数粘度、力学和热稳定性能。采用水辅混炼挤出直接将Hummers法制备并超声处理后的GO水溶液与PVDF混炼制备PVDF/GO纳米复合材料。结果表明,PVDF插层进入GO片层,使GO在PVDF基体中获得均匀分散,且两者之间形成氢键作用;同时PVDF剥离GO表面的氧化碎片,使GO发生一定程度原位热还原。GO含量较低的PVDF/GO纳米复合材料的储能模量、复数粘度、力学性能和热稳定性均有一定程度提高。采用间歇法制备PVDF和PP基多相体系的微孔发泡材料,探索发泡行为与发泡条件和材料特性之间的关系。对PVDF/GO复合材料,利用发泡过程中PVDF和PVDF/GO纳米复合材料的结晶和黏弹特性的差异等,来调控泡孔尺寸和密度等。对PP/HNTs复合材料,利用材料特性并通过控制发泡条件,获得椭球状泡孔和具有较高长径比的泡孔结构等。对PP/POE共混物,利用分散相相形态以及两相黏弹性和Sc-CO2溶解度的差异,获得椭球状、长孔状和开孔的泡孔结构,且泡孔形状、尺寸和密度等与分散相相形态有密切关系。总之,结合材料特性并控制发泡条件,可有效调控泡孔的形状、分布和尺寸等,获得多样化泡孔结构以适应不同用途的需求。
[Abstract]:The high performance preparation and structure control of polymer matrix nanocomposites and microcellular foamed polymer materials have been paid more and more attention by industry and academic circles. Related research. First of all, Based on the mechanism of water-assisted mixing, the experimental equipment of water-assisted mixing extrusion was constructed. Secondly, PP / HNTs and PVDF / GOG composites were prepared by water-assisted extrusion. Explore the mechanism of water promoting the dispersion of nanoparticles; finally, The PP/HNTs and PVDF/GO nanocomposites prepared by water-assisted extrusion and the blends prepared by ordinary extrusion were foamed. The PP/HNTs 85/15 composites were prepared by water-assisted extrusion. The dispersion of HNTs in PP matrix tends to be uniform with the increase of water injection rate, and the HNTs are uniformly dispersed and distributed in PP matrix when the water injection rate is 2 L / h. This indicates that the plasticization, vaporization and local expansion effect of water are observed in the mixing process. It can obviously promote the dispersion of HNTs. It can improve the storage modulus and complex viscosity of the composite. The mechanical and thermal stability properties of PVDF/GO nanocomposites were prepared by water assisted mixing and extruding the go aqueous solution prepared by Hummers method and mixed with PVDF by ultrasonic treatment. The results showed that the PVDF/GO nanocomposites were intercalated into the go lamellae and dispersed uniformly in the PVDF matrix. The hydrogen bond was formed between the two and the oxidation fragments of go surface were stripped by PVDF to some extent, the storage modulus and complex viscosity of PVDF/GO nanocomposites with low content of in situ thermal reduction. The mechanical properties and thermal stability were improved to some extent. The microcellular foaming materials of PVDF and PP based multiphase systems were prepared by batch method, and the relationship between foaming behavior and foaming conditions and material properties was explored. By using the difference of crystallization and viscoelastic properties of PVDF and PVDF/GO nanocomposites during foaming process, the size and density of foams are regulated. For PP/HNTs composites, the properties of the materials and the foaming conditions are controlled. The ellipsoidal bubble pore and the bubble pore structure with high aspect ratio were obtained. The morphology of dispersed phase and the difference of viscoelasticity between two phases and the solubility of Sc-CO2 were used to obtain the bubble structure of ellipsoid, long pore and open pore, and the bubble pore shape was obtained for the PP/POE blend, and the structure of the foam was obtained by using the morphology of the dispersed phase and the difference between the viscoelasticity of the two phases and the solubility of the Sc-CO2. The size and density are closely related to the morphology of the dispersed phase. In a word, the shape, distribution and size of the foam can be effectively controlled by combining the properties of the materials and controlling the foaming conditions, and various cellular structures can be obtained to meet the needs of different applications.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1

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