Determination of gel content of silane cross-linked polyethylene copolymers using FTIR technique

Document Type : Original research

Authors

1 Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran

2 Environmental Chemistry Research Centre. Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran

3 Pouya Gostar Mfg. Co. of Part Lastic Group, Mashhad, Iran

Abstract

Silane cross-linking of metallocene-based polyethylene-octene elastomer (POE)/linear low density polyethylene (LLDPE) blend was carried out using two-step Sioplas process in an industrial scale twin-screw extruder. In the study, grafting and cross-linking reactions of vinyl trimethoxy silane (VTMS) were analyzed using FTIR technique. It was found that the cured compound showed absorption peaks at 1078 cm-1 and 955 cm-1 related to Si-O-Si bonds. A peak was also observed at 3405 cm-1 of hydroxyl group produced from hydrolysis of methoxyethylene group during of curing process, reflecting that curing reaction was not completed. The samples were cured at different time intervals (15 min-16 hours). The gel content values determined by solvent extraction and FTIR were in good agreement at curing times more than 4 hours. The efficiency of the silane grafting reaction was determined using the ratio of the absorption peak at 1092 cm-1 characteristic of methoxy to the transmittance peak at 1378 cm-1 characteristic of methyl group, which  is considered as the internal standard. The results showed the highest efficiency of silane grafting reaction at 5 w% of VTMS with the least amount of internal standard ratio (0.029), at which the lowest MFI value, and the highest values for gel content, tear strength, compression set and hot set 200 °C were obtained.

Graphical Abstract

Determination of gel content of silane cross-linked polyethylene copolymers using FTIR technique

Keywords

Main Subjects

References

  1. Svoboda P, Poongavalappil S, Theravalappil R, Svobodova D, Mokrejs P, Kolomaznik K, Ougizawa T, Inoue T (2011) Cross-linking of ethylene-octene copolymer (EOC) by dicumyl peroxide (DCP). J Appl Polym Sci 121: 521-530 [CrossRef]
  2. Brydson JA (1995) Termoplastic elastomers: Properties and application, Ismithers Rapra Publishing, 13-16, Butter Worth Heinemann, 7th Ed, Oxford
  3. Theravalappil R (2012) Polyolefin Elastomers: A study on cross-linking, blends and composites, unpublished doctoral dissertation, Tomas Bata University, Czech Republic, Zlín
  4. Svoboda P, Poongavalappil S, Theravalappil R, Svobodova D, Mokrejs P (2013) Effect of octene content on proxide cross-linking of ethylene– octene copolymers. J Appl Polym Int 62: 184- 189 [CrossRef]
  5. Wang W, Gong W, Zheng B (2013) Preparation of low-density polyethylene foams with high rebound resilience by blending with polyethylene–octylene elastomer. Polym Eng Sci 53: 2527-2534 [CrossRef]
  6. Poongavalappil S, Svoboda P, Theravalappil R, Svobodova D, Danek M, Zatloukal M (2013) Study on the influence of electron beam irradiation on the thermal, mechanical, and rheological properties of ethylene-octene copolymer with high comonomer content. J Appl Polym Sci 128: 3026-3033 [CrossRef]
  7. Zhang G, Wang G, Zhang J, Wei P, Jiang P (2006) Performance evaluation of silane cross-linking of metallocene-based polyethylene–octene elastomer. J Appl Polym Sci 102: 5057–5061[CrossRef]
  8. Basuli U, Chaki TK, Naskar K (2008) Mechanical properties of thermoplastic elastomers based on silicone rubber and an ethylene–octene copolymer by dynamic vulcanization. J Appl Polym Sci 108: 1079-1085 [CrossRef]
  9. Chen WC, Lai SM, Qiu RY, Tang SX (2012) Role of silane cross-linking on the properties of melt blended metallocene polyethylene-g-silane/ clay nanocomposites at various clay contents. J Appl Polym Sci 124: 2669-2681 [CrossRef]
  10. Lai SM, Lui JL, Chen YC, Chang KH (2006) Fracture behaviors of metallocene-catalyzed polyethylene elastomer via silane cross-linking. J Appl Polym Sci 101: 2472-2481 [CrossRef]
  11. Lai SM, Liu JL, Hu SH, Huang CH, Wang SJ, Chien SC (2009) Fracture behaviors of metallocene catalyzed polyethylene elastomer via peroxide cross-linking. J Appl Polym Sci 113: 3791-3798 [CrossRef]
  12. Morshedian J, Mohammad Hoseinpour P (2009) Polyethylene cross-linking by two-step silane method: A Review. Iran Polym J 18: 103- 128 [CrossRef]
  13. ASTM D2765-95 a (2006) Standard test methods for determination of gel content and swell ratio of cross-linked ethylene plastics
  14. DIN 16892 (2001) Cross-linked high-density polyethylene (PE-X) pipes-general quality requirements and testing
  15. Peacock AJ (2000) Handbook of polyethylene, structures, properties, and applications, Marcel & Dekker, New York, 306-309
  16. Giacobbi E, Miglioli C (2005) Improved process for producing silane cross-linked polyethylene. WIPO, WO/2005/056620
  17. Hullihen K (2006) Determining gel content of polyethylene using a differential scanning calorimeter. Ind Eng Chem Res 45: 6095-6098 [CrossRef]
  18. Morshedian J, Mohammad Hoseinpour P, Azizi H, Parvizzad R (2009) Effect of polymer structure and additives on silane grafting of polyethylene. Express Polym Lett 3: 105-115 [CrossRef]
  19. Barzin J, Azizi H, Morshedian J (2006) Preparation of silane-grafted and moisture cross-linked low density polyethylene: Part I: Factors affecting performance of grafting and cross-linking. Polym Plast Tech Eng 45: 979–983 [CrossRef]
  20. Jiao C, Wang Z, Gui Z, Hu Y (2005) Silane grafting and crosslinking of ethylene–octene copolymer. Eur Polym J 41: 1204–1211 [CrossRef]
  21. Khonakdar HA, Morshedian J (2003) Wagenknecht U, Jafari SH, An investigation of chemical cross-linking effect on properties of high-density polyethylene. Polymer 44: 4301-4309 [CrossRef]
  22. Ahmed GS, Gilbert M, Mainprize S, Rogerson M (2009) FTIR analysis of silane grafted high density polyethylene. Plast Rubber Compos 38: 13-20 [CrossRef]
  23. Sirisinha K, Chimdist S (2006) Comparison of techniques for determining crosslinking in silane-water crosslinked materials. Polym Test 25: 518–526 [CrossRef]
  24. White JL, Coran AY, Moet A (2001) Polymer mixing: Technology and Engineering, Munich, Hanser Publishers, pp. 5
  25. White JL, Coran AY, Moet A (2001) Polymer mixing: Technology and engineering, Munich, Hanser Publishers, pp. 158
  26. Launer PJ (2008) Infrared analysis of organosilicon compounds: Spectra-structure correlations, http://www.gelest.com/ Library/11Infra.pdf, available on 21 December 2008
  27. Hjertberg T, Palmlof M, Sultan BÅ (1991) Chemical reactions in cross-linking of copolymers of ethylene and vinyltrimethoxy silane. J Appl Polym Sci 42: 1185-1192 [CrossRef]
  28. Shieh YT, Tsai TH (1998) Silane grafting reactions of low-density polyethylene. J Appl Polym Sci 69: 255-261 [CrossRef]
  29. Sirisinha K, Boonkongkaew M (2013) Improved silane grafting of high-density polyethylene in the melt by using a binary initiator and the properties of silane-crosslinked products. J Polym Res 20: 120 [CrossRef]
  30. Shah GB, Fuzail M, Anwar J (2004) Aspects of the cross-linking of polyethylene with vinyl silane. J Appl Polym Sci 92: 3796-3803 [CrossRef]
  31. Sirisinha K, Boonkongkaew M, Kositchaiyong S (2010) The effect of silane carriers on silane grafting of high-density polyethylene and properties of crosslinked products. Polym Test 29: 958–965 [CrossRef]
  32. Barzin J, Azizi H, Morshedian J (2007) Preparation of silane-grafted and moisture crosslinked low density polyethylene. Part II: Electrical, thermal and mechanical properties. Polym-Plast Tech Eng 46: 305–310[CrossRef]

Files

Cited by

History

  • Receive Date: 16 August 2023
  • Revise Date: 23 September 2023
  • Accept Date: 25 September 2023
  • First Publish Date: 26 September 2023

Share

How to cite

Statistics