| As one of the five thermoplastic general plastic, Polypropylene (PP) was the one that growing fastest due to its excellent processing and using performance. Compositing with glass fiber which were called GRTP were widely applied in automotive, aerospace, construction, sports equipment and so on. With the vigorous development of auto industry, GRTP dosage was gradually increasing. The recycling of GRTP scrap has attracted the attention of researchers, which was related to industry development and the well-being of future generations. In this paper, glass fiber reinforced polypropylene composites have been successfully fabricated via double screw extrusion by using mechanical crushed leftover materials as the raw materials, in addition, which have been met the target product performance requirements. The rheological behavior, mechanical performance and enhanced/toughening mechanism of different kinds composites were studied and investigating the effects on the crystallization behavior of PP at the same time.(1) The analyzing of raw materials showed that fabric fibers were random entwining morphology rather than melting under the processing temperature (180-220℃). The matrix was a crystal polypropylene; moreover,33.66%glass fiber in RGRTP which prove the significance of recycling. Five different binary composites were prepared by melt blending,10phr to50phr RGRTP contents, respectively. The rheological, thermal, mechanical properties and crystallization behavior were discussed in detail. In conclusion, RGRTP affected the crystallization behavior of PP, Tc and crystallization rate raised, while spherulite size and Xc reduced. With the increase of RGRTP content, η*decreased and fiber began to slight agglomerations occurred at the30phr contents. Initial decomposition temperature and peak temperature of the composites expressed the tendency of rise after drop firstly. In the meantime, flexural strength and modulus increased which was responsible to the rigid effect of glass fiber, however, the impact strength decreased and probably kept in6kJ·m-2.(2) In order to reduce the cost of industrial production and meet the requirements of higher modulus and appropriated toughness, therefore, inorganic rigid particle CaCO3was chose as filling materials. Discussing the corresponding properties like as rheological, thermal, mechanical properties and crystallization behavior of composites with different ratios of CaCO3. When increasing the content of CaCO3, modulus improved. Meanwhile, only as the content of CaCO3was less than10phr, strength and toughness increased. Storage modulus of the composites was raised, but η*decreased first and then increased. Because of the heterogeneous nucleation effect of CaCO3, Tc was raised instead of△T and t1/2decreased.(3) On account of the requirements for toughness but toughening effect was always limited of inorganic rigid particle, adding thermoplastic elastomer POE to increase the impact strength, consequently. Discussion focused on toughening mechanism, thermodynamic performance and crystallization behavior of composites. In a word, POE as a dispersed phase in the PP matrix which belongs to parts compatibility. Even though the toughness of the composites was improved, its strength and rigidity decreased. This may be owing to the bad interface bonding between inorganic rigid particles and matrix. Since flexible long chain structure of POE affected the crystallization behavior of PP, X0and AT declined. Thermal stability and η*of composites were decreased for the low modulus of POE. Tanδ shoulder peak appeared as the content of POE was less than5phr. When the ratios of POE was10phr, the cost(RMB6350/t) and mechanical performance of the composites met the requirements of target products. |
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