【作者】 黄利；

【导师】 瞿金平；

【作者基本信息】 华南理工大学 ， 材料加工工程， 2010， 硕士

【摘要】 为充分利用现有资源扩大高分子材料的应用领域,目前对聚合物进行共混改性的研究变得越来越活跃。当前,对不相容共混体系的改性研究主要侧重于研制新型的相容剂,而挤出共混设备对材料的聚集态结构、分散混合状况及材料的宏观力学性能也同样起着至关重要的作用。华南理工大学瞿金平教授最新研制的叶片挤出机彻底摒弃了基于剪切流变的螺杆挤出加工方式,通过采用正位移的输送原理及引入拉伸流场的作用方式,使得聚合物在叶片挤出机中具有热-机械历程短、降解程度小、物料混合效果好等特点。本文通过选用PS/HDPE不相容的两相体系来研究叶片挤出机加工对共混物分散混合、微观相态、热行为及宏观力学性能的影响规律。为较好的开展实验研究工作,本文特从多个角度来进行考察,依次为:(1)分别选用纯PS及HDPE来分析物料在叶片及普通单螺杆挤出机中的降解及停留时间特性;(2)选用不同配比的PS/HDPE共混物经来研究在叶片挤出机的作用下分散相含量对体系相态及分散混合的影响规律;(3)选用低黏度比及高黏度比的PS/HDPE共混体系来研究不同拉伸流场强度对该体系分散混合状况及相转变速率的影响;(4)向PS/HDPE(30/70)体系中添加相容剂SEBS来分析叶片挤出机加工对体系相态及界面作用的影响。研究表明:与螺杆挤出机相比,物料在叶片挤出机的塑化过程中降解程度较小、物料停留时间更短。经叶片挤出机加工的PS/HDPE的分散相平均粒径尺寸变得较小(约0.25~1um),分布较均匀,界面间的粘结作用较强。同时,共混物在较低的转速下微观相态结构由交错互锁的双连续相结构向“海岛结构转变”,且分散相平均尺寸进一步得到减小。另外,添加少量的SEBS可较好的对PS/HDPE(30/70)进行相容改性。更多还原

【Abstract】 In order to fully utilize resources and expand the applications of polymer materials, it seems that the modification research of incompatible blends became more and more popular. At present, the modification of polymer blends focused primarily on developing new compatibilizers,while the blending equipments also act as the vital player in the course of polymer blends processing.Because it could improve the dispersing and mixing effect of dispersing phase materials in the two phase systems and influence the aggregation structures of polymer blends. Professor Qu Jinping,from South China University of Technology, developed a newly uniaxial vane extruder which completely abandoned the screw extruder based on shear flow field.The polymer heat-mechanical process became more shortly、the degree of degradation became more slightly and the effect of dispersing and mixing improved more obviously through the use of positive displacement conveying principle and the introduction of elongation flow field in the vane extruder.In this paper, the PS/HDPE blends were selected to research the law of dispersing and mixing、micro-phase struture、thermal behaviors and macro-mechanical properties in the vane extruder.In order to precisely describle the micro-structure and properties of PS/HDPE blends in the vane extruder,the experiments were done from various perspectives as below respectively: (1) pure PS and HDPE were used to analyze the residence time and the degradation properties in the vane and screw extruders; (2) use the different mass proportions of PS/HDPE blends to study the law of dispersing and mixing and evolution rules of polymer blends phase strutures as the variation of dispersed phase content in the extruding process of vane extruder;(3) use the PS / HDPE blends of low viscosity and high viscosity ratio to study dispersion mixing status and rate of phase transformation in different flow field intensity; (4)add the compatibilizer SEBS in PS/HDPE(30/70) to analyze the phase structure and the interface adhension effect bettwen the dispersed and continuous phase.The results show that: compared with the screw extruder, the molecular weight of PS decreased less、the residence time of HDPE in the vane extruder stayed shortly.The dispersed phase mean particle size of PS/HDPE blends became small(0.25um~1um),the distribution became homogeniusly by vane extruding processing . In the vane extruder, the phase evolution from“sea-island”structure to co-continous structure can be took place at low rotate speed,the“sea-island”structure formed as rotate speed increased and the dispersed mean particles became more small.the campatibilization of PS/HDPE(30/70) blends can been improved through adding little amount of SEBS .更多还原