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Study Effects of Nucleating Agent and Nano Reinforecment on Crystalline Structure and Mechanical Properties of Polypropylene Block Copolymer

Shahsavan, Shakiba | 2017

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  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 50293 (07)
  4. University: Sharif University of Technology
  5. Department: Materials Science and Engineering
  6. Advisor(s): Bagheri, Reza
  7. Abstract:
  8. Polypropylene block copolymer is used in different industries like pipe productions. This copolymer has proper mechanical properties, specially it has good impact strength, but in some applications it’s elastic modulus (stiffness) is not enough and that leads to some problemes in servise. Nucleating agents influence crystalline structure and properties and also the mechanical properties by controlling the crystallization process. Nanoparticles also have a beneficial effects on physical and mechanical properties. In this study, the effect of adding two types of α-phase nucleating agents (commercial names NA11 and DMDBS) in the form of masterbatch wt 5% with a carrier of polypropylene block copolymer and the effect of adding DMDBS nucleating agents 5 wt% in masterbatch with the carrier of the polypropylene hemopolymer, the final content of nucleating agent is 0.2, 0.4 and 0.6 wt%, in to Polypropylene block copolymer that has been purchased from Arak petrochemical. Also, the effect of adding nanoclay in the form of masterbatch with 20 wt% compatibilizer and 5 wt% nanoclay and 75 wt% polypropylene hemopolymer with final contents of 0.8, 1.6 and 2.4 wt%, and the effect of simultaneous addition of DMDBS with the carrier of polypropylene hemopolymer in masterbatch and Nanoclay with the masterbatch mentioned above were also investigated.The differential scanning calorimetry test (DSC) was used to determine the crystallization temperature, spherulite’s nucleation and growth rate, and the rate of crystallization and X-ray diffraction to determine the existing crystalline phases and crystallinity, and optical microscopy was used to observe the spherulite’s structure.Tensile and impact tests were performed to investigate mechanical properties. NA11 nucleating agent with weight percentages of 0.1, 0.2 and 0.3 wt%, increase crystallization temperature, spherulite’s nucleation and growth rate, and the rate of crystallization, thereby increasing the modulus more than the DMDBS nucleating agent and decreasing more the impact strength. And both nucleating agents increase the amount of β-phase due to their masterbatch’ carrier. The DMDBS nucleating agent with the carrier of polypropylene hemopolymer in the masterbatch is superior to that of the DMDBS nucleating agent with the carrier of polypropylene block copolymer in the masterbatch and more than the nanoclay, increases the crystallinity, crystallization temperature and modulus, and is used due to the masterbatch’carrier, By adding nucleating agent or nanoclay, the ß phase is reduced and the amount of α phase is increased. Simultaneous addition of DMDBS and nanoclay also increases the crystallization temperature and increases the crystallinity and modulus more than nanoclay and less than nucleating agents lonely. But decrease impact strength less than nanoclay
  9. Keywords:
  10. Nucleating Agent ; Nanoclay ; Nanocomposite ; Mechanical Properties ; Crystalline Structure ; Copolymer Polypropylene

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