Comparison of grafting of maleic anhydride onto linear low density polyethylene with hexene-1 and butene-1 comonomers and prediction of optimum ingredients by response surface methodology

Document Type : Original research

Authors

Faculty of processing, Iran Polymer and Petrochemical Institute, 14977-13115, Tehran, Iran

Abstract

In this work, the grafting of maleic anhydride onto two types of linear low density polyethylene with hexene-1 comonomer (LLDPE-H1) and butene-1 comonomer (LLDPE-B1), in the presence of styrene monomer (St) and dicumyl peroxide initiator (DCP) has been studied. The combined influences of MAH, St and DCP on the grafting efficiency via a melt reactive mixing process have been investigated using response surface methodology and the central cubic design has been employed for experimental design and data analysis. IR spectroscopy, contact angle measurements and adhesion test have been used to evaluate the extent of grafting reaction. The results showed that LLDPE-H1 with a 2.2% maximum grafting content showed more grafting content than the LLDPE-B1 (1.86%). This effect could be attributed to the type of comonomer in LLDPE-H1 which made it more prone to chain scission than LLDPE-B1, and a higher level of grafting was achieved. The gel content measurement showed that lower cross-linked structure was formed during the grafting process in the LLDP-H1 than that in the LLDPE-B1. The optimum conditions of maximum grafting and minimum gel content were statically investigated. The optimum percentage of grafting for LLDPE-H1 was 1.82% and it was 1.74% for LLDPE-B1, with the minimum gel content of 6.5% and 9%, respectively. It was found that the amount of grafted percentage was sensitive to the concentrations of the MAH, DCP, and St, while the extent of the gel content was more sensitive to the percentage of DCP.

Keywords

Main Subjects


  1. Moad G (1999) Synthesis of polyolefin graft copolymers by reactive extrusion. Prog Polym Sci 24:81-142
  2. Passaglia E, Coiai S, Augier S (2009) Control of macromolecular architecture during the reactive functionalization in the melt of olefin polymers. Prog Polym Sci 34:911-947
  3. Jahani Y, Valavi A, Ziaee F (2015) Reactive melt modification of polyethylene by ethyl acrylate / acrylic acid copolymers : Rheology , morphology and thermal behavior. Iran Polym J 24: 449-458
  4. Shieh Y, Chuang H, Liu C (2001) Water crosslinking reactions of silane-grafted polyolefin blends. J Appl Polym Sci 1799-1807
  5. Clark DC, Baker WE, Whitney RA (2001) Peroxide-initiated comonomer grafting of styrene and maleic anhydride onto polyethylene: effect of polyethylene microstructure. J Appl Polym Sci 79: 96-107
  6. Liu W, Liu T, Liu T, Liu T, Xin J, Hiscox WC, Liu H, Liu L, Zhang J (2017) Improving grafting efficiency of dicarboxylic anhydride monomer on polylactic acid by manipulating monomer structure and using comonomer and reducing agent. Ind Eng Chem Res 56: 3920-3927
  7. Galland GB, Seferin M, Mauler RS, Dos Santos JHZ (1999) Linear low-density polyethylene synthesis promoted by homogeneous and supported catalysts. Polym Int 48: 660-664
  8. Bettini SHP, Ruvolo Filho AC (2008) Styreneassisted grafting of maleic anhydride onto polypropylene by reactive processing. J Appl Polym Sci 107:1430-1438
  9. Ramos D, Helson M, Rocha MCG (2006) Study of different peroxide types on the modification of LLDPE . Part 1. Factorial experimental design and thermal properties. Polym Test 25:306-312
  10. Khuri AI, Mukhopadhyay S (2010) Response surface methodology. Wiley Interdiscip Rev Comput Stat 2:128-149
  11. Shi Q, Zhu L, Cai C, Yin JH, Costa G (2005) Kinetics study on melt grafting copolymerization of LLDPE with acid monomers using reactive extrusion method. J Appl Polym Sci 101: 4301-4312
  12. Velthoen MEZ, Muñoz-Murillo A, Bouhmadi A, Cecius M, Diefenbach S, Weckhuysen BM (2018) The multifaceted role of methylaluminoxane in metallocene-based olefin polymerization catalysis. Macromolecules 51:343-355
  13. Brintzinger HH, Fischer D, Mülhaupt R, Rieger B, Waymouth RM (1995) Stereospecific olefin polymerization with chiral metallocene catalysts. Angew Chemie Int Ed Eng 34:1143-1170
  14. Shamiri A, Chakrabarti MH, Jahan S, Hussain MA, Kaminsky W, Aravind PV, Yehye WA (2014) The influence of Ziegler-Natta and metallocene catalysts on polyolefin structure, properties, and processing ability. Materials 7: 5069-5108
  15. Platzer N (1983) Branched polyethylene : LDPE and LLDPE. Ind Eng Chem Res 158-160
  16. Kaminsky W (1980) Ziegler-Natta Catalysis. Adv Organomet Chem 18: 99-149
  17. Pii P, Marigo A, Zannetti R, Milani F (1997) A small- and wide-angle X-ray scattering study of 1-butene LLDPE obtained by metallocene and Ziegler-Natta catalysis. Eur Polym J 33:595–598
  18. Neumann AW, Good RJ (1979) Techniques of measuring contact angles. In: Surface and colloid science. Springer, pp 31–91
  19. Sa S (2000) Polyethylene grafted maleic anhydride to improve wettability of liquid on polyethylene films. J Appl Polym Sci 1802-1808
  20. Sathe SN, Rao GSS, Dev S (1994) Grafting of maleic anhydride onto polypropylene : Synthesis and characterization. J Appl Polym Sci 239-245
  21. Ma P, Jiang L, Ye T, Dong W, Chen M (2014) Melt free-radical grafting of maleic anhydride onto biodegradable poly(lactic acid) by using styrene as a comonomer. Polymers 6:1528-1543
  22. Schaible S, Meincke O, Schulthess A, Brändli C (2018) Process optimization for improved adhesion in the grafting of triethoxyvinylsilane on VLDPE via reactive extrusion. Eur Polym J 107:9-14
  23. Lee BK, Park JH, Park SH, Kim JH, Oh SH, Lee SJ, Lee BY, Kim MS (2017) Preparation of pendant group-functionalized diblock copolymers with adjustable thermogelling behavior. Polymers 9: 239
  24. Berda EB, Wagener KB (2008) Inducing pendant group interactions in precision polyolefins: synthesis and thermal behavior. Macromolecules 41:5116-5122
  25. Detyothin S, Selke SEM, Narayan R, Rubino M, Auras R (2013) Reactive functionalization of poly (lactic acid), PLA: Effects of the reactive modifier, initiator and processing conditions on the final grafted maleic anhydride content and molecular weight of PLA. Polym Degrad Stab 98: 2697-2708
  • Receive Date: 01 August 2020
  • Revise Date: 02 October 2020
  • Accept Date: 24 October 2020
  • First Publish Date: 24 October 2020