Polymer Bulletin

, Volume 76, Issue 2, pp 865–881 | Cite as

The α-, β-, and γ-polymorphs of polypropylene–polyethylene random copolymer modified by two kinds of β-nucleating agent

  • Jiaxin Fu
  • Xinpeng Li
  • Man Zhou
  • Rui Hong
  • Jie ZhangEmail author
Original Paper


The α-, β-, and γ-polymorphs of polypropylene random copolymer with two kinds of β-nucleating agent (TMB-5 and WBG-2) have been studied via wide-angle X-ray diffraction and differential scanning calorimetry. It was found that the addition of 0.5 wt% β-nucleating agent (β-NA) hardly induces appreciable β-modification content, until β-NA content is up to 1 wt%. It seems that low amount of β-NA is not enough to counterbalance the nucleation ability and high content of defects (stereo- and regioerrors) of co-PP, and only α- and γ-modifications are obtained in the samples. Moreover, the relative amount of γ-crystal depends on the crystallization temperature. Although TMB-5 has better heterogeneous nucleation effect than WBG-2, the ability to form stable β-polymorph of WBG-2 is stronger than that of TMB-5. Since large amount of β-nucleation sites overcome the defects of co-PP molecular chain and curb the formation of γ-crystal, competitive growth of α- and β-polymorphs ultimately leads to the coexistence of α- and β-modification.


Polypropylene random copolymer β-nucleating agent γ-crystal β-modification 



We would like to express our great thanks to National Natural Science Foundation of China (51433006) and Sichuan Science and Technology Project (2017JY0069) for financial support.


  1. 1.
    Varga J (1992) Supermolecular structure of isotactic polypropylene. J Mater Sci 27:2557–2579CrossRefGoogle Scholar
  2. 2.
    Phillips PJ, Mezghani K (1996) Polypropylene, isotactic (polymorphism). In: Salamone JC (ed) The polymeric materials encyclopedia, vol 9. CRC Press, Boca Raton, p 6637Google Scholar
  3. 3.
    Cerrada ML (2009) Formation of the new trigonal polymorph in iPP–1-hexene copolymers. Competition with the mesomorphic phase. Macromolecules 42:702–708CrossRefGoogle Scholar
  4. 4.
    Corradini P, de Rosa C, Guerra G, Petraccone V (1989) Comments on the possibility that the mesomorphic form of isotactic polypropylene is composed of small crystals of the β crystalline form. Polym Commun 30:281–285Google Scholar
  5. 5.
    Arranz-Andrés J, Benavente R, Pérez E, Cerrada ML (2003) Structure and mechanical behavior of the mesomorphic form in a propylene-b-poly(ethylene-co-propylene) copolymer and its comparison with other thermal treatments. Polym J 35:766–777CrossRefGoogle Scholar
  6. 6.
    Brückner S, Meille SV, Petraccone V, Pirozzi B (1991) Polymorphism in isotactic polypropylene. Prog Polym Sci 16:361–404CrossRefGoogle Scholar
  7. 7.
    Lotz B, Wittmann JC, Lovinger AJ (1996) Structure and morphology of poly(propylenes): a molecular analysis. Polymer 37:4979–4992CrossRefGoogle Scholar
  8. 8.
    Krache R, Benavente R, López-Majada JM (2007) Competition between α, β, and γ polymorphs in a β-nucleated metallocenic isotactic polypropylene. Macromolecules 40:6871–6878CrossRefGoogle Scholar
  9. 9.
    Natta G, Corradini P (1960) Crystal structure of poly-ortho-methylstyrene. Nuovo Cimento Suppl 15:40CrossRefGoogle Scholar
  10. 10.
    Meille SV, Ferro D, Brückner S, Lovinger AJ, Padden FJ (1994) Structure of beta-isotactic polypropylene: a long-standing structural puzzle. Macromolecules 27:2615–2622CrossRefGoogle Scholar
  11. 11.
    Mezghani K, Phillips PJ (1998) The γ-phase of high molecular weight isotactic polypropylene: III. The equilibrium melting point and the phase diagram. Polymer 39:3735–3744CrossRefGoogle Scholar
  12. 12.
    Dimeska A, Phillips PJ (2006) High pressure crystallization of random propylene–ethylene copolymers: αγ phase diagram. Polymer 47:5445–5456CrossRefGoogle Scholar
  13. 13.
    Varga J (1995) Crystalline, melting and supermolecular structure of isotactic polypropylene. In: Karger-Kocsis J (ed) Polypropylene: structure, blends and composites, vol 1. Chapman and Hall, London, p 56CrossRefGoogle Scholar
  14. 14.
    Zhou M, Li XP (2016) Simultaneously improving the tensile and impact properties of isotactic polypropylene with the cooperation of co-PP and β-nucleating agent through pressure vibration injection molding. Chin J Polym Sci 34:1001–1013CrossRefGoogle Scholar
  15. 15.
    Liu ZZ, Liu XH (2017) Mechanical enhancement of melt-stretched β-nucleated isotactic polypropylene: the role of lamellar branching of β-crystal. Polym Test 58:227–235CrossRefGoogle Scholar
  16. 16.
    Brückner S, Meille SV (1989) Non-parallel chains in crystalline γ-isotactic polypropylene. Nature 340:455–457CrossRefGoogle Scholar
  17. 17.
    Addink EJ, Beintema J (1961) Polymorphism of crystalline polypropylene. Polymer 2:185–193CrossRefGoogle Scholar
  18. 18.
    Sowinski P, Piorkowska E (2016) Nucleation of crystallization of isotactic polypropylene in the gamma form under high pressure in nonisothermal conditions. Eur Polym J 85:564–574CrossRefGoogle Scholar
  19. 19.
    Mezghani K, Phillips PJ (1997) The γ-phase of high molecular weight isotactic polypropylene. II: the morphology of the γ-form crystallized at 200 Mpa. Polymer 38:5725–5733CrossRefGoogle Scholar
  20. 20.
    Hosier IL, Alamo RG, Esteso P, Isasi JR, Mandelkern L (2003) Formation of the α and γ polymorphs in random metallocene–propylene copolymers. Effect of concentration and type of comonomer. Macromolecules 36:5623–5636CrossRefGoogle Scholar
  21. 21.
    De Rosa C, Aurienma F, Paolillo M, Resconi L, Camurati I (2005) Crystallization behavior and mechanical properties of regiodefective, highly stereoregular isotactic polypropylene:  effect of regiodefects versus stereodefects and influence of the molecular mass. Macromolecules 38:9143–9154CrossRefGoogle Scholar
  22. 22.
    Wiyatno W, Fuller GG, Pople JA, Gast AP, Chen Z, Waymouth RM, Myers CL (2003) Component stress–strain behavior and small-angle neutron scattering investigation of stereoblock elastomeric polypropylene. Macromolecules 36:1178–1187CrossRefGoogle Scholar
  23. 23.
    Wiyatno W, Chen Z, Liu Y, Waymouth RM, Krukonis V, Brennan K (2004) Heterogeneous composition and microstructure of elastomeric polypropylene from a sterically hindered 2-arylindenylhafnium catalyst. Macromolecules 37:701–708CrossRefGoogle Scholar
  24. 24.
    Auriemma F, De Rosa C (2002) Crystallization of metallocene-made isotactic polypropylene:  disordered modifications intermediate between the α and γ forms. Macromolecules 35:9057–9068CrossRefGoogle Scholar
  25. 25.
    Auriemma F, De Rosa C (2006) Stretching isotactic polypropylene:  from “cross-β” to crosshatches, from γ form to α form. Macromolecules 39:7635–7647CrossRefGoogle Scholar
  26. 26.
    Alamo RG, Ghosal A, Chatterjee J, Thompson KL (2005) Linear growth rates of random propylene ethylene copolymers. The changeover from γ dominated growth to mixed (α + γ) polymorphic growth. Polymer 46:8774–8789CrossRefGoogle Scholar
  27. 27.
    Jeona K, Palza H, Quijada R, Alamo RG (2009) Effect of comonomer type on the crystallization kinetics and crystalline structure of random isotactic propylene 1-alkene copolymers. Polymer 50:832–844CrossRefGoogle Scholar
  28. 28.
    Poon B, Rogunova M, Hiltner A, Baer E, Chum SP, Galeski A, Piorkowska E (2005) Structure and properties of homogeneous copolymers of propylene and 1-hexene. Macromolecules 38:1232–1243CrossRefGoogle Scholar
  29. 29.
    De Rosa C, Auriemma F, de Ballesteros OR, Resconi L, Camurati I (2007) Crystallization behavior of isotactic propylene–ethylene and propylene–butene copolymers:  effect of comonomers versus stereodefects on crystallization properties of isotactic polypropylene. Macromolecules 40:6600–6616CrossRefGoogle Scholar
  30. 30.
    De Rosa C, Auriemma F, de Ballesteros OR, De Luca D, Resconi L (2008) The double role of comonomers on the crystallization behavior of isotactic polypropylene:  propylene–hexene copolymers. Macromolecules 41:2172–2177CrossRefGoogle Scholar
  31. 31.
    Alamo RG, Kim M-H, Galante MJ, Isasi JR, Mandelkern L (1999) Structural and kinetic factors governing the formation of the γ polymorph of isotactic polypropylene. Macromolecules 32:4050–4064CrossRefGoogle Scholar
  32. 32.
    Gou Q, Li H, Yu Z, Chen E, Zhang Y, Yan S (2007) Crystallization behavior of a propylene-1-butene random copolymer in its α and γ modifications. Colloid Polym Sci 285:1149–1155CrossRefGoogle Scholar
  33. 33.
    Luo Feng, Chenlong Xu, Wang Ke (2012) Exploring temperature dependence of the toughening behavior of β-nucleated impact polypropylene copolymer. Polymer 53:1783–1790CrossRefGoogle Scholar
  34. 34.
    Lotz B (1998) α and β phases of isotactic polypropylene: a case of growth kinetics `phase reentrency’ in polymer crystallization. Polymer 39(19):4561–4567CrossRefGoogle Scholar
  35. 35.
    Li JX, Cheung WL (1998) On the deformation mechanisms of β-polypropylene: effect of necking on β-phase PP crystals. Polymer 39(26):6935–6940CrossRefGoogle Scholar
  36. 36.
    Li JX, Cheung WL (1999) A study on the heat of fusion of β-polypropylene. Polymer 40(8):1219–1222CrossRefGoogle Scholar
  37. 37.
    Turner-Jones A, Cobbold A (1968) The β crystalline form of isotactic polypropylene. J Polym Lett 6:539–546CrossRefGoogle Scholar
  38. 38.
    Turner JA, Aizlewood J, Beckett D (1964) Crystalline forms of isotactic polypropylene. Makromol Chem 75:134–153CrossRefGoogle Scholar
  39. 39.
    Zhang Y, Zhang L, Liu H (2013) Novel approach to tune mechanics of β-nucleation agent nucleated polypropylene: role of oriented β spherulite. Polymer 54(21):6026–6035CrossRefGoogle Scholar
  40. 40.
    Natta G, Corradini P (1960) Structure and properties of isotactic polypropylene. Nuovo Cimento Suppl 15:40–51CrossRefGoogle Scholar
  41. 41.
    Brückner S, Meille SV (1989) Non-parallel chains in crystalline γ-isotactic polypropylene. Nature 340(6233):455–457CrossRefGoogle Scholar
  42. 42.
    Jeziorny A (1978) Parameters characterizing the kinetics of the non-isothermal crystallization of poly(ethylene terephthalate) determined by d.s.c. Polymer 19(10):1142–1144CrossRefGoogle Scholar
  43. 43.
    Razavi-Nouri Mohammad (2009) Study of non-isothermal crystallization kinetics of single-walled carbon nanotubes filled polypropylene using Avrami and Mo models. Iran Polym J 18(2):167–178Google Scholar
  44. 44.
    Joshi A, Butola BS (2004) Studies on nonisothermal crystallization of HDPE/POSS nanocomposites. Polymer 45(14):4953–4968CrossRefGoogle Scholar
  45. 45.
    Ahmed J, Luciano G, Schizzi I, Arfat YA, Maggiore S (2018) Non-isothermal crystallization behavior, rheological properties and morphology of poly(ε-caprolactone)/graphene oxide nanosheets composite films. Thermochim Acta 659:96–104CrossRefGoogle Scholar
  46. 46.
    Jape SP, Deshpande VD (2017) Nonisothermal crystallization kinetics of nylon 66/LCP blends. Thermochim Acta 655:1–12CrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.State Key Laboratory of Polymer Materials Engineering, College of Polymer Science and EngineeringSichuan UniversityChengduChina

Personalised recommendations