玻璃纤维及PET纤维增强聚丙烯复合材料的结构与性能研究

发布时间：2019-04-21 07:51

【摘要】：制备优良力学性能的聚合物/纤维复合材料是近年来国内外高分子领域研究的热点之一,许多学者重点研究纤维的表面改性、基体的改性,以期获得有效的界面粘结性,而目前针对纤维的分散性、团聚现象,以及通过纤维混杂方法从而提高复合材料性能的相关研究报道较少。基于此,本文以聚丙烯(PP)、玻璃纤维(GF)及PET纤维为研究对象,从以下两个方面进行研究:首先,针对熔融挤出制备玻璃纤维增强聚丙烯复合材料过程易造成纤维团聚,导致纤维分散性差的问题,本文将玻璃纤维的分散过程和界面粘结过程单独分开来完成,制得具有优越分散性的玻璃纤维(NGF),并与传统玻璃纤维(LGF)做对比,分别制备了LGF、NGF增强聚丙烯(PP)复合材料进,探讨了纤维团聚现象对PP结构与性能的影响。其次,选取PET纤维和GF进行混杂,与PP熔融共混制备出PP/PET纤维/GF复合材料,并将其分别在230?C和265?C下注塑制得标准试样。探讨了注射成型温度,及PET纤维和GF混杂体系对PP结构与性能的影响。实验结果表明:(1)SEM分析发现,NGF在基体树脂中呈单根地均匀分散,而LGF在基体树脂中明显观察到大量的纤维团聚现象。表明,NGF制备成功。(2)DSC和WAXD分析表明,相比LGF,NGF增强PP复合材料熔融峰更宽、结晶度更高。力学性能测试表明,在玻璃纤维含量低,且界面粘结性较差时,玻璃纤维的团聚在承载外力的作用上可能更有利。然而,当界面粘结性提高后,玻璃纤维团聚成为不利因素,呈单根均匀分散的玻璃纤维能更好地发挥增强作用。(3)注射成型温度直接影响最终材料中PET相的分散形态。在230?C下注射成型时,PET纤维没有发生熔融,其分散态仍为纤维状。而在265?C时.PET纤维发生熔融.其分散态为颗粒状。(4)GF和PET纤维可以混杂增强PP。PET分散态为颗粒状时,其与PP的界面粘结性更好。但混杂体系并不能诱导PP基体形成新的晶型,晶体结构为稳定的α晶。对比230?C及265?C注塑的试样,前者表现出较高的热稳定性,而后者表现出更高的拉伸强度。
[Abstract]:The preparation of polymer / fiber composites with excellent mechanical properties is one of the hot spots in polymer field at home and abroad in recent years. Many scholars focus on the surface modification and matrix modification of fibers in order to obtain effective interfacial adhesion. However, there are few reports on the dispersion of fibers, the phenomenon of agglomeration, and the improvement of the properties of composites by fiber hybrid method. Based on this, in this paper, polypropylene (PP), glass fiber (GF) and PET fiber as the research object, from the following two aspects: firstly, the process of melt extrusion of glass fiber reinforced polypropylene composites is easy to cause fiber agglomeration, In order to solve the problem of poor dispersion of fiber, the dispersion process of glass fiber and the bonding process of interface were separated separately, and the glass fiber (NGF), with superior dispersion was prepared and compared with the traditional glass fiber (LGF). LGF,NGF reinforced polypropylene (PP) composites were prepared respectively. The effect of fiber agglomeration on the structure and properties of PP was discussed. Secondly, the PET fiber / GF composite was prepared by melt blending of PP/PET fiber and GF, and the standard sample was prepared by injection of PP/PET fiber and GF under 230 C and 265 C, respectively. The effects of injection molding temperature and hybrid system of PET fiber and GF on the structure and properties of PP were discussed. The results showed that: (1) SEM analysis showed that NGF was uniformly dispersed in the matrix resin, while a large number of fiber agglomerations were observed in the LGF matrix resin. The results show that the preparation of NGF is successful. (2) DSC and WAXD analysis show that the melting peak is wider and the crystallinity is higher than that of LGF,NGF reinforced PP composites. The mechanical properties test shows that when the content of glass fiber is low and the interfacial adhesion is poor, the agglomeration of glass fiber may be more favorable to the loading of external force. However, when the interfacial adhesion is improved, the glass fiber aggregation becomes an unfavorable factor, and the single uniformly dispersed glass fiber can play a better role in strengthening. (3) the injection molding temperature directly affects the dispersion morphology of PET phase in the final material. During injection molding at 230 C, the PET fiber did not melt and its dispersed state was still fibrous. However, PET fibers melt at 265 C. The dispersed state is granular. (4) the interfacial adhesion between GF and PET fiber is better when the dispersed state of PP.PET is granular. (4) when the dispersion state of PP.PET fiber is granular, the interfacial adhesion between the fiber and PP is better. However, the hybrid system could not induce the formation of a new crystal form in PP matrix, and the crystal structure was a stable 伪 crystal. Compared with 230 C and 265 C, the former shows higher thermal stability, while the latter shows higher tensile strength.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB332

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