Molecular dynamics simulation of static crystallization and tensile deformation of bimodal HDPE/UHMWPE: Influence of long chain content

Document Type : Original research

Authors

Shanghai Key Laboratory of Multiphase Material Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China

Abstract

The effect of long chain content (XL ) on the static crystallization and tensile deformation mechanisms of bimodal HDPE/UHMWPE was investigated by molecular dynamics simulations. The crystallization of HDPE/ UHMWPE undergoes three stages: nucleation, rapid growth of lamellar crystals, and stabilization. The increase of XL leads to the formation of more nucleation sites, which promotes nucleation, but at the same time leads to an increase of entanglement sites, which is not conducive to the movement of the long chains to the growth front to fold and form lamellar crystals. Tensile deformation is performed on the crystallized models and the systems exhibit three stages: elastic deformation, plastic deformation and stress hardening. During deformation, the increase of XL improves the orientation nucleation and crystallinity (Xc), but when XL exceeds 4 wt.%, the entanglement effect becomes more pronounced, leading to a decrease in Xc. The effect of temperature is also taken into account: at low temperatures, a suitable range (2-4 wt.%) exists to optimize the mechanical properties of the material. At high temperatures, there is almost no stress-hardening phenomenon, but the addition of long chains has an impeding effect on the melting of the lamellar crystals, and when XL is greater than 8 wt.%, stress-induced melting is more likely to occur, accelerating the melting of the crystals.

Keywords

Main Subjects

References

  1. Watters EP, Spedding PL, Grimshaw J, Duffy JM, Spedding RL (2005) Wear of artificial hip joint material. Chem Eng J 112: 137-144 [CrossRef]
  2. Song S, Wu P, Ye M, Feng J, Yang Y (2008) Effect of small amount of ultra high molecular weight component on the crystallization behaviors of bimodal high density polyethylene. Polymer 49: 2964-2973 [CrossRef]
  3. Hofmann D, Kurek A, Thomann R, Schwabe J, Mark S, Enders M, Hees T, Mülhaupt R (2017) Tailored nanostructured HDPE wax/UHMWPE reactor blends as additives for melt-processable all-polyethylene composites and in situ UHMWPE fiber reinforcement. Macromolecules 50: 8129-8139 [CrossRef]
  4. Huang YF, Xu JZ, Zhang ZC, Xu L, Li LB, Li JF, Li ZM (2017) Melt processing and structural manipulation of highly linear disentangled ultrahigh molecular weight polyethylene. Chem Eng J 315:132-141 [CrossRef]
  5. Farrar DF, Brain AA (1997) The microstructure of ultra-high molecular weight polyethylene used in total joint replacements. Biomaterials 18: 1677-1685 [CrossRef]
  6. Knuuttila H, Lehtinen A, Nummila-Pakarinen A (2004) Advanced polyethylene technologies—controlled material properties. Adv Polym Sci 169: 13-27 [CrossRef]
  7. Lim KL, Ishak ZM, Ishiaku US, Fuad AM, Yusof AH, Czigany T, Pukanzsky B, Ogunniyi DS (2006) High density polyethylene/ultra high molecular weight polyethylene blend. II. Effect of hydroxyapatite on processing, thermal, and mechanical properties. J Appl Polym Sci 100: 3931-3942 [CrossRef]
  8. Zou H, Chen Y, Liang M (2014) Dynamic rheological behavior of polyethylene/ultra-high-molecular-weight polyethylene blends. Chin Polymer Bulletin 2: 130-136
  9. Kurtz SM, Muratoglu OK, Evans M, Edidin AA (1999) Advances in the processing, sterilization, and crosslinking of ultra-high molecular weight polyethylene for total joint arthroplasty. Biomaterials 20: 1659-1688 [CrossRef]
  10. Bohm LL, Enderle HF, Fleifßner M (1992) High‐density polyethylene pipe resins. Adv Mater 4: 234-238 [CrossRef]
  11. Moreno J, Paredes B, Carrero A, Vélez D (2017) Production of bimodal polyethylene on chromium oxide/metallocene binary catalyst: Evaluation of comonomer effects. Chem Eng J 315: 46-57 [CrossRef]
  12. Gholami F, Pircheraghi G, Rashedi R, Sepahi A (2019) Correlation between isothermal crystallization properties and slow crack growth resistance of polyethylene pipe materials. Polymer Testing 80: 106128 [CrossRef]
  13. Xu L, Huang YF, Xu JZ, Ji X, Li ZM (2014) Improved performance balance of polyethylene by simultaneously forming oriented crystals and blending ultrahigh-molecular-weight polyethylene. RSC Advances 4:1512-1520 [CrossRef]
  14. Wang Y, Li T, Zun Q (2018) Study on the fluidity and mechanical properties of UHMWPE/HDPE blends. Shanxi Chem Ind 5: 18-20
  15. Hoffman JD, Miller RL. Kinetic of crystallization from the melt and chain folding in polyethylene fractions revisited: theory and experiment. Polymer 38: 3151-3212 [CrossRef]
  16. Strobl G (2006) Crystallization and melting of bulk polymers: New observations, conclusions and a thermodynamic scheme. Prog polym Sci 31: 398-442 [CrossRef]
  17. Strobl G (2009) Colloquium: Laws controlling crystallization and melting in bulk polymers. Rev Mod Phys 81: 1287-1300 [CrossRef]
  18. Chen Y, Zou H, Liang M, Liu P (2013) Study on the dynamic rheological behavior of four different bimodal polyethylenes. J Macromolecular Sci-B 52: 924-936 [CrossRef]
  19. Yang L, Somani RH, Sics I, Hsiao BS, Kolb R, Fruitwala H, Ong C (2004) Shear-induced crystallization precursor studies in model polyethylene blends by in-situ rheo-SAXS and rheo-WAXD. Macromolecules 37: 4845-4859 [CrossRef]
  20. Hsiao B, Yang L, Somani R, Zhu L (2005) Unexpected Shish-Kebab Structure in Shear-Induced Polyethylene Melt. In: APS March Meeting Abstracts, pp. X30-007
  21. Zhao L, Hu Y, Shao Y, Liu Z, Liu B, He X. Molecular dynamics simulation of shish-kebab crystallization of polyethylene: Unraveling the effects of molecular weight distribution. The J Chem Phys150: 184114-184114 [CrossRef]
  22. Lv F, Chen X, Wan C, Su F, Ji Y, Lin Y, Li X, Li L (2017) Deformation of ultrahigh molecular weight polyethylene precursor fiber: crystal slip with or without melting. Macromolecules 50: 6385-6395 [CrossRef]
  23. Yang F, Gao H, Hu W (2012) Monte Carlo simulations of crystallization in heterogeneous copolymers: The role of copolymer fractions with intermediate comonomer content. J Mater Res 27: 1383-1388 [CrossRef]
  24. Nie Y, Zhao Y, Matsuba G, Hu W (2018) Shish-kebab crystallites initiated by shear fracture in bulk polymers. Macromolecules 51: 480-487 [CrossRef]
  25. Guan X, Wang Y, Wang J, Wu Y, Hu W (2019) Effects of short‐chain branches on strain‐induced polymer crystallization. Polym Int 68: 225-230 [CrossRef]
  26. Hu Y, Shao Y, Liu Z, He X, Liu B (2019) Dominant effects of short-chain branching on the initial stage of nucleation and formation of tie chains for bimodal polyethylene as revealed by molecular dynamics simulation. Polymers 11: 1840 [CrossRef]
  27. Jeong S, Kim JM, Cho S, Baig C (2017) Effect of short-chain branching on interfacial polymer structure and dynamics under shear flow. Soft Matter 14: 470 [CrossRef]
  28. Sanmartín S, Ramos J, Vega JF, Martínez-Salazar J (2014) Strong influence of branching on the early stage of nucleation and crystal formation of fast cooled ultralong n-alkanes as revealed by computer simulation. Eur Polym J 50: 190-199 [CrossRef]
  29. Lee S, Rutledge GC (2011) Plastic deformation of semicrystalline polyethylene by molecular simulation. Macromolecules 44: 3096-3108 [CrossRef]
  30. Kim JM, Locker R, Rutledge G (2014) Plastic deformation of semicrystalline polyethylene under extension, compression, and shear using molecular dynamics simulation. Macromolecules 47: 2515-2528 [CrossRef]
  31. Yeh IC, Andzelm JW, Rutledge GC (2015) Mechanical and structural characterization of semicrystalline polyethylene under tensile deformation by molecular dynamics simulations. Macromolecules 48: 4228-4239 [CrossRef]
  32. Yeh IC, Lenhart JL, Rutledge GC, Andzelm JW (2017) Molecular dynamics simulation of the effects of layer thickness and chain tilt on tensile deformation mechanisms of semicrystalline polyethylene. Macromolecules 50: 1700-1712 [CrossRef]
  33. Ranganathan R, Kumar V, Brayton AL, Kroger M, Rutledge GC. Atomistic modeling of plastic deformation in semicrystalline polyethylene: Role of interphase topology, entanglements, and chain dynamics. Macromolecules 53: 4605-4617 [CrossRef]
  34. Hossain D, Tschopp MA, Ward DK, Bouvard JL, Wang P, Horstemeyer MF (2010) Molecular dynamics simulations of deformation mechanisms of amorphous polyethylene. Polymer 51: 6071-6083 [CrossRef]
  35. Hu Y, Shao Y, Liu Z, He X, Liu B (2019) Dominant effects of short-chain branching on the initial stage of nucleation and formation of tie chains for bimodal polyethylene as revealed by molecular dynamics simulation. Polymers 11: 1840 [CrossRef]
  36. Chatterjee AK, Morgan JP, Scholl M, Grubbs RH (2000) Synthesis of functionalized olefins by cross and ring-closing metatheses. J Am Chem Soc 122: 3783-3784 [CrossRef]
  37. Natta G (1959) Kinetic studies of α‐olefin polymerization. J Polym Sci 34: 21-48 [CrossRef]
  38. Kaminsky W (2004) The discovery of metallocene catalysts and their present state of the art. J Polym Sci Pol Chem 42: 3911-3921 [CrossRef]
  39. Agapie T (2011) Selective ethylene oligomerization: Recent advances in chromium catalysis and mechanistic investigations. Coord Chem Rev 255:861-880 [CrossRef]
  40. Mayo SL, Olafson BD, Goddard WA (1990) DREIDING: a generic force field for molecular simulations. J Phys Chem 94: 8897-8909 [CrossRef]
  41. Yu X, Kong B, Yang X (2008) Molecular dynamics study on the crystallization of a cluster of polymer chains depending on the initial entanglement structure. Macromolecules 63: 197-204 [CrossRef]
  42. Jordens K, Wilkes GL, Janzen J, Rohlfing DC, Welch MB (2000) The influence of molecular weight and thermal history on the thermal, rheological, and mechanical properties of metallocene-catalyzed linear polyethylenes. Polymer 41: 7175-7192 [CrossRef]
  43. Lavine MS, Waheed N, Rutledge GC (2003) Molecular dynamics simulation of orientation and crystallization of polyethylene during uniaxial extension. Polymer 44: 1771-1779 [CrossRef]
  44. Balzano L, Rastogi S, Peters GW (2009) Crystallization and precursors during fast short-term shear. Macromolecules 42: 2088-2092 [CrossRef]
  45. Fernandez-Ballester L, Thurman DW, Zhou W, Kornfield JA (2012) Effect of long chains on the threshold stresses for flow-induced crystallization in iPP: Shish kebabs vs sausages. Macromolecules 45: 6557-6570 [CrossRef]
  46. Jabbari-Farouji S, Rottler J, Lame O, Makke A, Perez M, Barrat JL (2015) Plastic deformation mechanisms of semicrystalline and amorphous polymers. ACS Macro Lett [CrossRef]
  47. Gao R, He X, Shao Y, Hu Y, Zhang H, Liu Z, Liu B (2016) Effects of branch content and branch length on polyethylene crystallization: Molecular dynamics simulation. Macromol Theory Simul 25: 303-311 [CrossRef]
  48. Yamamoto T (2019) Molecular dynamics simulation of stretch-induced crystallization in polyethylene: Emergence of fiber structure and molecular network. Macromolecules 52: 1695-706 [CrossRef]
  49. Cao Y, Zhao L, Wang J, Shao Y, He X (2021) Molecular dynamics simulation of extension-induced crystallization of branched bimodal HDPE: Unraveling the effects of short-chain branches. Phys Chem Chem Phys 23: 19862–19871 [CrossRef]
  50. Gilbert M, Hybart FJ (1972) Effect of chemical structure on crystallization rates and melting of polymers: Part 1. Aromatic polyesters. Polymer 13: 327-332 [CrossRef]

Files

History

  • Receive Date: 02 April 2024
  • Revise Date: 19 June 2024
  • Accept Date: 29 June 2024
  • First Publish Date: 02 July 2024

Share

How to cite

Statistics