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A new approach to increase toughness of synthesized PP/EPR in-reactor blends by introducing a copolymerization step under low ethylene concentration

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Abstract

Complex microstructure of the polypropylene/ poly(ethylene-co-propylene) in-reactor blends has been the subject of many studies. In this work simple two-step polymerization procedure was considered and effects of adding another copolymerization step with low ethylene concentration were investigated. The blends microstructure and morphology as well as mechanical properties were studied. The blends were characterized using dynamic mechanical thermal analysis (DMTA), gel permeation chromatography (GPC), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and temperature gradient elution fractionation (TGEF). It was found that adding an extra copolymerization step under low ethylene concentration caused considerable increase in the blends toughness, elongation at break and the number of very small dispersed particles in the polypropylene matrix. The mentioned polymerization step produced copolymers having long polypropylene sequences capable to take part in crystallization of polypropylene matrix, suggested acting as linkage between rubber and polypropylene phases. Although the amorphous copolymer related to the additional copolymerization step had a role in decreasing the average size of dispersed phase, the difference in crystallizable copolymer microstructure suggested had a key role in marked enhancement of mechanical properties.

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References

  1. Ven S (1990) Polypropylene and other polyolefins: polymerization and characterization. Elsevier, Amsterdam

    Google Scholar 

  2. Martuscelli E (1995) Structure and properties of polypropylene-elastomer blends. In: Karger-Kocsis J (ed) Polypropylene structure, blends and composites. Chapman & Hall, London

    Google Scholar 

  3. Liang JZ, Li RKY (2000) Rubber toughening in polypropylene: a review. J Appl Polym Sci 77:409–417

    Article  CAS  Google Scholar 

  4. Chiu HT, Shiau YG, Chiu WM, Syau SS (1995) Toughening isotactic polypropylene and propylene-ethylene block copolymer with styrene-ethylene butylene-styrene triblock copolymer. J Polym Res 2:21–29

    Article  CAS  Google Scholar 

  5. Yokoyama Y, Ricco T (1998) Toughening of polypropylene by different elastomeric systems. Polymer 39:3675–3681

    Article  CAS  Google Scholar 

  6. Soni R, Singh H, Dutt K, Arora P (2010) Effect of dynamic cross-linking on mixing torque behavior and tensile yield behavior of isotactic polypropylene (iPP) / ethylene-propylene diene rubber (EPDM) /nitrile rubber (NBR) elastomeric blends. J Polym Res 17:411–427

    Article  CAS  Google Scholar 

  7. Zhu L, Xu X, Sheng J (2011) Study on phase structure and evolution of PP/PEOc blends during heat preservation process under quiescent condition. J Polym Res 18:1269–1275

    Article  CAS  Google Scholar 

  8. Galli P, Vecellio G (2001) Technology: driving force behind innovation and growth of polyolefins. Prog Polym Sci 26:1287–1336

    Article  CAS  Google Scholar 

  9. Galli P (1994) The breakthrough in catalysis and processes for olefin polymerization: Innovative structures and a strategy in the materials area for the twenty-first century. Prog Polym Sci 19:959–974

    Article  CAS  Google Scholar 

  10. McKenna T, Bouzid D, Matsunami S, Sugano T (2003) Evolution of particle morphology during polymerisation of high Impact polypropylene. Polym React Eng 11:177–197

    Article  CAS  Google Scholar 

  11. Du J, Niu H, Dong JY, Dong X, Han CC (2008) Self-similar growth of polyolefin alloy particles in a single granule multi- catalyst reactor. Adv Mater 20:2914–2917

    Article  CAS  Google Scholar 

  12. Chen Y, Chen Y, Chen W, Yang D (2008) Multilayered core–shell structure of the dispersed phase in high-impact polypropylene. J Appl Polym Sci 108:2379–2385

    Article  CAS  Google Scholar 

  13. Zhang C, Shangguan Y, Chen R, Zheng Q (2011) Study on thermal behavior of impact polypropylene copolymer and its fractions. J Appl Polym Sci 119:1560–1566

    Article  CAS  Google Scholar 

  14. Cai H, Luo X, Ma D, Wang J, Tan H (1999) Structure and properties of impact copolymer polypropylene. I Chain structure. J Appl Polym Sci 71:93–101

    Article  CAS  Google Scholar 

  15. Tong C, Lan Y, Chen Y, Chen Y, Yang D, Yang X (2012) The functions of crystallizable ethylene-propylene copolymers in the formation of multiple phase morphology of high impact polypropylene. J Appl Polym Sci 123:1302–1309

    Article  CAS  Google Scholar 

  16. Liu YL, Xu JT, Dong Q, Fu ZS, Fan ZQ (2009) Crystallization behavior of the blends of isotactic polypropylene and ethylene-propylene blocky copolymers. Polym Plast Technol Eng 48:333–341

    Article  CAS  Google Scholar 

  17. Zhang C, Shangguan Y, Chen R, Wu Y, Chen F, Zheng Q, Hu G (2010) Morphology, microstructure and compatibility of impact polypropylene copolymer. Polymer 51:4969–4977

    Article  CAS  Google Scholar 

  18. Tan H, Li L, Chen Z, Song Y, Zheng Q (2005) Phase morphology and impact toughness of impact polypropylene copolymer. Polymer 46:3522–3527

    Article  CAS  Google Scholar 

  19. Rungswang W, Saendee P, Thitisuk B, Pathaweeisariyakul T, Cheevasrirungruang W (2013) Role of crystalline ethylene-propylene copolymer on mechanical properties of impact polypropylene copolymer. J Appl Polym Sci 128:3131–3140

    Article  CAS  Google Scholar 

  20. Doshev P, Lohse G, Henning S, Krumova M, Heuvelsland A, Michler G, Radusch HJ (2006) Phase interactions and structure evolution of heterophasic ethylene-propylene copolymers as a function of system composition. J Appl Polym Sci 101:2825–2837

    Article  CAS  Google Scholar 

  21. Pires M, Mauler RS, Liberman SA (2004) Structural characterization of reactor blends of polypropylene and ethylene-propylene rubber. J Appl Polym Sci 92:2155–2162

    Article  CAS  Google Scholar 

  22. Zhang YQ, Fan ZQ, Feng LX (2002) Influences of copolymerization conditions on the structure and properties of isotactic polypropylene/ethylene–propylene random copolymer in situ blends. J Appl Polym Sci 84:445–453

    Article  CAS  Google Scholar 

  23. Fan Y, Zhang C, Xue Y, Nie W, Zhang X, Ji X, Bo S (2009) Effect of copolymerization time on the microstructure and properties of polypropylene/poly (ethylene-co-propylene) in-reactor alloys. Polym J 41:1098–1104

    Article  CAS  Google Scholar 

  24. Dong Q, Fu Z, Xu J, Fan Z (2007) Strong influences of cocatalyst on ethylene/propylene copolymerization with a MgCl2/SiO2/TiCl4/diester type Ziegler-Natta catalyst. Eur Polym J 43:3442–3451

    Article  CAS  Google Scholar 

  25. Dong Q, Wang X, Fu Z, Xu J, Fan Z (2007) Regulation of morphology and mechanical properties of polypropylene/poly(ethylene-co-propylene) in-reactor alloys by multi-stage sequential polymerization. Polymer 48:5905–5916

    Article  CAS  Google Scholar 

  26. Li Y, Xu J, Dong Q, Fu Z, Fan Z (2009) Morphology of polypropylene/poly(ethylene-co-propylene) in-reactor alloys prepared by multi-stage sequential polymerization and two-stage polymerization. Polymer 50:5134–5141

    Article  CAS  Google Scholar 

  27. Bagheri H, Nekoomanesh M, Hakim S, Jahani Y, Fan ZQ (2011) Structural parameters in relation to the rheological behavior and properties of PP/EPR in-reactor alloy synthesized by multi-stage sequential polymerization. J Appl Polym Sci 121:3332–3339

    Article  CAS  Google Scholar 

  28. Tian Z, Gu XP, Wu GL, Feng LF, Fan ZQ, Hu G-H (2011) Periodic switching of monomer additions for controlling the compositions and microstructures of segmented and random ethylene-propylene copolymers in polypropylene in-reactor alloys. Ind Eng Chem Res 50:5992–5999

    Article  CAS  Google Scholar 

  29. Kittilsen P, McKenna TF (2001) Study of the kinetics, mass transfer, and particle morphology in the production of high-impact polypropylene. J Appl Polym Sci 82:1047–1060

    Article  CAS  Google Scholar 

  30. Shin YW, Uozumi T, Terano M, Nitta KH (2001) Synthesis and characterization of ethylene-propylene random copolymers with isotactic propylene sequence. Polymer 42:9611–9615

    Article  CAS  Google Scholar 

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Correspondence to Shokoufeh Hakim.

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Moballegh, L., Hakim, S., Morshedian, J. et al. A new approach to increase toughness of synthesized PP/EPR in-reactor blends by introducing a copolymerization step under low ethylene concentration. J Polym Res 22, 73 (2015). https://doi.org/10.1007/s10965-015-0709-3

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  • DOI: https://doi.org/10.1007/s10965-015-0709-3

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