【作者】 盛亚俊；

【导师】 邓剑如；

【作者基本信息】 湖南大学 ， 应用化学， 2005， 硕士

【摘要】 层状共混技术以其工艺相对简单，而且对环境没有污染，生产过程中的回收料可以重复使用、复合物的阻隔性能优异，已经成为当今世界阻隔包装材料领域的研究热点，世界各国无论是学术界还是产业界都在积极地对这一新兴功能材料领域进行研究与开发。 前人已在单螺杆挤出成型设备上对其进行了深入的研究，层状共混技术是通过选择具有合适粘度比的共混组份，并改善两相间的热力学不相容性，采用恰当的成型加工工艺条件，来实现阻隔性树脂在基体树脂中形成层状相分布，但是在双螺杆挤出机中的研究很少，国内尚未见报导。本文正是基于这种状况，通过选择合适的原材料，改变同向双螺杆挤出机流场控制，研究层状共混物在双螺杆挤出机中的形成规律，在此研究结果的基础上研制开发层状共混阻隔材料。 实验首先在对牌号为F600、5000S和5502的三种高密度聚乙烯(HDPE)、牌号为1013B的尼龙6(PA6)及牌号为WP56153的聚对苯二甲酸乙二醇酯(PET)的相关性能测试分析的基础上，采用双螺杆挤出机在不同螺杆转速下制备具有不同粘度比的共混物样品，采用扫描电镜对样品的微观形态进行了观测和分析。从中选择了最适合作为层状共混改性的两个共混体系(即HDPE 5502／PA6 1013B和HDPE 5502／PETWP56153)针对这两个体系，通过改变双螺杆挤出机的工艺参数(温度分布、螺杆转速及喂料频率)及相容剂的用量，讨论了这两种共混物分散相层状结构的形成机理。并对层状共混制品的阻隔性能及力学性能进行了研究。结果表明，加入一定含量的相容剂既有利于提高共混物的阻隔性能又能改善其力学性能。 其次，对HDPE 5502／PA6 1013B和HDPE 5502／PET层状共混物的阻隔性能进行了比较，并结合在双螺杆挤出机中层状形态形成的相关条件，对两个体系的开发前景进行了分析，分析结果表明HDPE 5502／PA6 1013B层状共混物更适合作为阻隔材料的开发体系。 最后，在塑料自动吹瓶机上进一步研究了温度分布及螺杆速率对HDPE5502／PA6共混物分散形态的影响，研制出的层状共混吹塑瓶对烃类溶剂的阻隔性能较HDPE中空吹塑瓶有了较大幅度的提高，并对层状共混吹塑瓶的阻隔性能影响因素进行了分析。更多还原

【Abstract】 The barrier solutions presently available on the market all have their drawbacks, e.g. cost or perceived environmental bad-will. This situation has stimulated the industry to provide new, more efficient barrier solutions. The use of laminar morphology of polymer blends to obtain good barrier (i.e., low permeability) to hydrocarbons has been of considerable interest recently. Such a structure will represent a long, tortuous path for the gas or solvent penetrating the blend.Laminar morphology has been demonstrated in single screw extruders and blowing machines. Both processes have shown that viscosity and elasticity ratios, and interfacial tension between the matrix and dispersed phase, are important parameters in the development of the morphology of blends . To our knowledge, few studies have been done regarding the development of laminar morphology in the twin screw extruders. The main objective of this work was to evaluate the formation of laminar morphology of polymer blends in a co-rotating twin screw extruder and prepare the barrier containers.Firstly, the morphology of samples of different HDPE/PA6 and HDPE/PET blends obtained by three kinds of HDPE and rotational speeds was observed using SEM. Appropriate selection of materials in combination with SEM photos and material parameters results in developing laminar morphology in co-rotating twin screw extruder of HDPE/PA6 and HDPE/PET blends. Temperature profile, shear rate and screw rate, as the processing parameters, and compatibilizer levels were considered in this study. The study provides the basis for choosing processing conditions and polymer blend components to obtain expected laminar morphology of polymer blends. Furthermore, the barrier and mechanical properties of the blends were evaluates and optimized. In order to obtain products with optimum balance between the permeability and the mechanical properties, a statistical analysis was carried out.Secondly, it is showed that HDPE/PA6 blend is better than HDPE/PET blends by the statistical evaluation of permeability results and the analysis of blow- molding process.Finally, temperature profile and shear rate was used to optimize processing conditions in developing laminar morphology in blow molding HDPE/PA6 blends. The result is shown that it is good to form laminar morphology of dispersed phase PA6 in proper temperature profile and lower shear rate. It is also shown that blow molded bottles with laminar blend of HDPE and PA6 reduce greatly in permeability, compared to the bottles made from HDPE.更多还原