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Investigation on chain structure of LLDPE obtained by ethylene in-situ copolymerization with DSC and XRD

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Chinese Science Bulletin

Abstract

Thermal segregations of LLDPE were treated with successive self-nucleation/annealing (SSA) on differential scanning calorimetry (DSC). Information on molecular heterogeneity of LLDPE was obtained. After SSA was treated, the multiple endothermic peaks were observed in the DSC thermograms during heating experiment. It is obtained that the thickness of different lamellas formed by segments of various lengths was 4–10 nm. X-ray diffraction (XRD) results showed that the crystallites dimensions of various reflections were about several dozens of nanometers. The ethylene/α-olefin copolymers and the copolymer via in-situ copolymerization were similar to each other for molecular heterogeneity and XRD characteristics, which revealed that it was possible to use the ethylene/α-olefin copolymers to simulate the copolymer via in-situ copolymerization of ethylene to simplify the complexity of the structure of the ethylene in-situ copolymer.

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References

  1. Halasz L, Belina K, Vorster O C, et al. Rheological, thermal and crystallisation properties of ethylene, propylene and α-olefin copolymers. II Thermal and crystallization properties. Plast Rubb Compos, 2004, 33(5): 205–211

    Article  Google Scholar 

  2. Gupta P, Garth L, Beyer, et al. Does the length of the short chain branch affect the mechanical properties of linear low density polyethylenes? An investigation based on films of copolymers of ethylene/1-butene, ethylene/1-hexene and ethylene/1-octene synthesized by a single metallocene catalyst. Polymer, 2005, 46(20): 8819–8837

    Google Scholar 

  3. Pan L, Liu Y G, Zhang K Y, et al. Investigation of the effect of branched structure on the performances of the copolymers synthesized from ethylene and α-olefin with rac-Et(Ind)2ZrCl2/MMAO catalyst system. Polymer, 2006, 47(4): 1465–1472

    Article  Google Scholar 

  4. Yoon J S, Lee D H, Jung S O, et al. Thermal and mechanical properties of ethylene/α-olefin copolymers produced over (2-MeInd)2ZrCl2/MAO system. Polymer, 2000, 41(12): 4523–4530

    Article  Google Scholar 

  5. Beach D L, Kissin Y V. Dual functional catalysis for ethylene polymerization to branched polyethylene, I. Evaluation of catalytic systems. J Polym Sci A: Polym Chem, 1984, 22(11): 3027–3042

    Google Scholar 

  6. Kissin Y V, Beach D L. Dual functional catalysis for ethylene polymerization to branched polyethylene, II. Homogeneous-heterogeneous Ziegler-Natta catalyst system. J Polym Sci A: Polym Chem, 1986, 24(6): 1069–1084

    Article  Google Scholar 

  7. Denger C, Haase U, Fink G. Simultaneous oligomerization and polymerization of ethylene. Macromol Rapid Commun, 1991, 12(12): 697–701

    Article  Google Scholar 

  8. Musikabhumma K, Spaniol T P, Okuda J. Synthesis of branched polyethylenes by the tandem catalysis of silica-supported linked cyclopentadienyl-amido titanium catalysts and a homogeneous Dibromo nickel catalyst having pyridylimine ligand. J Polym Sci A: Polym Chem, 2003, 41(4): 528–544

    Article  Google Scholar 

  9. Barnhart R W, Bazan G C. Synthesis of branched polyolefins using a combination of homogeneous metallocene mimics. J Am Chem Soc, 1998, 120(5): 1082–1083

    Article  Google Scholar 

  10. Liu Z Y, Xu D M, Wang J, et al. LLDPE prepared by in situ polymerization using a dual-functional catalytic system of Ti(On-Bu)4/AlEt3-Et(Ind)2-ZrCl2/MAO, Chin Sci Bull, 2001, 46(24): 2051–2053

    Article  Google Scholar 

  11. Liu Z Y, Wang J, Xu D M, et al. Preparation of long-branched polyethylene by in situ poly-merization using late transition metal and metallocene catalysts, Chin Sci Bull, 2001, 46(24): 2054–2057

    Article  Google Scholar 

  12. Zhu F M, Huang Y, Yang Y J, et al. Branched polyethylene prepared by in-situ copolymerization of ethylene with monotitanocene and modified methylaluminoxane catalyst. J Polym Sci A: Polym Chem, 2000, 38(23): 4258–4263

    Article  Google Scholar 

  13. Quijada R, Rojas R, Bazan G, et al. Synthesis of branched polyethylene from ethylene by tandem action of iron and zirconium single site catalyst. Macromolecules, 2001, 34(8): 2411–2417

    Article  Google Scholar 

  14. Galland G B, Quijada R, Rojas R, et al. NMR study of branched polyethylene obtained with combined Fe and Zr catalysts. Macromolecules, 2002, 35(2): 339–345

    Article  Google Scholar 

  15. Wang H, Yan W, Jiang T, et al. Ethylene oligomerization by novel iron(II) diimine complexes / MAO. Chin Sci Bull, 2002, 47(19): 1616–1618

    Article  Google Scholar 

  16. Müller A J, María L A. Thermal fraction of polymers. Prog Polym Sci, 2005, 30(5): 559–603

    Google Scholar 

  17. Wang Z M, He X X, Sun D Q. Applied Infrared Spectra (in Chinese). Beijing: Petrochemistry Industry Press, 1978. 371–373

    Google Scholar 

  18. Randall J C. A review of high resolution liquid 13Carbon. Nuclear magnetic resonance characterizations of ethylene-based polymers. JMS-Rev Macromol Chem Phys, 1989, C29(23): 201–317

    Google Scholar 

  19. Chen F, Robert A Shanks*, Amarasinghe G. Molecular distribution analysis of melt-crystallized ethylene copolymers. Polym Int, 2004, 53(11): 1795–1805

    Article  Google Scholar 

  20. Mo Z S, Zhang H F. Structures of the Crystallization Polymer and X-ray (in Chinese). Beijing: Science Press, 2003. 228–229

    Google Scholar 

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Authors and Affiliations

  1. Institute of Polymer Science and Engineering, School of Chemical Engineering, Key Laboratory of Green Chemical Technology and Efficient Energy Saving of Hebei Province, Hebei University of Technology, Tianjin, 300130, China

    Wang YanJie & Yan WeiDong

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  1. Wang YanJie
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  2. Yan WeiDong
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Correspondence to Yan WeiDong.

Additional information

Supported by the National Natural Science Foundation of China (Grant No. 50573018) and Doctoral Foundation of Hebei Province (Grant No. 05547003D-6)

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Wang, Y., Yan, W. Investigation on chain structure of LLDPE obtained by ethylene in-situ copolymerization with DSC and XRD. CHINESE SCI BULL 52, 736–742 (2007). https://doi.org/10.1007/s11434-007-0093-4

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  • DOI: https://doi.org/10.1007/s11434-007-0093-4

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