Advertisement

Iranian Polymer Journal

, Volume 27, Issue 5, pp 329–337 | Cite as

Formation of 3D networks in polylactic acid by adjusting the cross-linking agent content with respect to processing variables: a simple approach

  • Roya Pourshooshtar
  • Zahed Ahmadi
  • Faramaz Afshar Taromi
Original Research
  • 37 Downloads

Abstract

High-performance biodegradable polymers have attracted considerable attention over the years because of their eco-friendly nature. The effects of processing variables on the efficiency of crosslinking, and the rheological and thermal properties of cross-linked polylactic acid (XPLA) have not been comprehensively addressed yet. In this work, XPLA was prepared through solution casting followed by curing in an oven. Enhancements in properties could be quantified in terms of structural changes in 3D structure of XPLA by varying the amount of dicumyl peroxide (DCP) as a cross--linking agent and curing temperature and time. The XPLAs were characterized by differential scanning calorimetry, thermo-gravimetric analysis, swelling, and rheological techniques. The swelling data revealed an increase in gel fraction by 1.32% per 1 °C temperature rise in the range of 125–195 °C. The results were also indicative of an increase in gel faction by 0.32% per minute in the time range of 5–100 min. Maximum variation in gel fraction occurred at 195 °C with high peroxide content. At this temperature, the variation rate of gel content was about 14.99%. With gel formation evolution, especially at 85% completion stage, the melting point was vanished. Rheological measurements showed that the Newtonian plateau disappeared for the cross-linked samples, simultaneously with the onset of shear thinning and zero-shear viscosity, through which the molecular weight obtained by the Mark–Houwink equation shifted to lower frequencies. A mathematical model based on the Charlesby–Pinner equation was developed for predicting the gel content of the XPLA as a function of curing time and peroxide concentration. The Flory–Huggins parameter also changed during the cross-linking process as a function of cross-linking density. This study is focused on adjusting cross-linking density and processing factors, like temperature and time, to achieve an XPLA with desirable properties.

Keywords

Cross-linked polylactic acid Dicumyl peroxide Cross-link density Swellingm Charlesby–Pinner equation 

Supplementary material

13726_2018_613_MOESM1_ESM.docx (696 kb)
Supplementary material 1 (DOCX 696 kb)

References

  1. 1.
    Zarrintaj P, Bakhshandeh B, Rezaeian I, Heshmatian B, Ganjali MR (2017) A novel electroactive agarose-aniline pentamer platform as a potential candidate for neural tissue engineering. Sci Rep 7:17187CrossRefGoogle Scholar
  2. 2.
    Mozafari M, Gholipourmalekabadi M, Chauhan N, Jalali N, Asgari S, Caicedoa J, Hamlekhan A, Urbanska A (2015) Synthesis and characterization of nanocrystalline forsterite coated poly (l-lactide-co-β-malic acid) scaffolds for bone tissue engineering applications. Mater Sci Eng, C 50:117–123CrossRefGoogle Scholar
  3. 3.
    Zarrintaj P, Moghaddam AS, Manouchehri S, Atoufi Z, Amiri A, Amirkhani MA, Nilforoushzadeh MA, Saeb MR, Hamblin MR, Mozafari M (2017) Can regenerative medicine and nanotechnology combine to heal wounds? The search for the ideal wound dressing. Nanomedicine 12:2403–2422CrossRefGoogle Scholar
  4. 4.
    Martinez FAC, Balciunas EM, Salgado JM, González JMD, Converti A, de Souza Oliveira RP (2013) Lactic acid properties, applications and production: a review. Trends Food Sci Technol 30:70–83CrossRefGoogle Scholar
  5. 5.
    Homklin R, Hongsriphan N (2013) Mechanical and thermal properties of PLA/PBS co-continuous blends adding nucleating agent. Energy Procedia 34:871–879CrossRefGoogle Scholar
  6. 6.
    Xia X, Shi X, Liu W, Zhao H, Li H, Zhang Y (2017) Effect of flax fiber content on polylactic acid (PLA) crystallization in PLA/flax fiber composites. Iran Polym J 26:693–702CrossRefGoogle Scholar
  7. 7.
    Lashgari S, Karrabi M, Ghasemi I, Azizi H, Messori M (2016) Graphene nanoplatelets dispersion in poly (l-lactic acid): preparation method and its influence on electrical, crystallinity and thermomechanical properties. Iran Polym J 25:193–202CrossRefGoogle Scholar
  8. 8.
    Di Y, Iannace S, Di Maio E, Nicolais L (2005) Reactively modified poly (lactic acid): properties and foam processing. Macromol Mater Eng 290:1083–1090CrossRefGoogle Scholar
  9. 9.
    Li BH, Yang MC (2006) Improvement of thermal and mechanical properties of poly (L-lactic acid) with 4, 4-methylene diphenyl diisocyanate. Polym Adv Technol 17:439–443CrossRefGoogle Scholar
  10. 10.
    Jin F, Hyon SH, Iwata H, Tsutsumi S (2002) Crosslinking of poly (L-lactide) by γ-irradiation. Macromol Rapid Commun 23:909–912CrossRefGoogle Scholar
  11. 11.
    Ng HM, Bee ST, Ratnam C, Sin LT, Phang YY, Tee TT, Rahmat A (2014) Effectiveness of trimethylopropane trimethacrylate for the electron-beam-irradiation-induced cross-linking of polylactic acid. Nucl InstrumMethodsPhys Res B319:62–70CrossRefGoogle Scholar
  12. 12.
    Ren Z, Li H, Sun X, Yan S, Yang Y (2012) Fabrication of high toughness poly (lactic acid) by combining plasticization with cross-linking reaction. Ind Eng Chem Res 51:7273–7278CrossRefGoogle Scholar
  13. 13.
    Yang SL, Wu ZH, Yang W, Yang MB (2008) Thermal and mechanical properties of chemical crosslinked polylactide (PLA). Polym Test 27:957–963CrossRefGoogle Scholar
  14. 14.
    Nagasawa N, Kaneda A, Kanazawa S, Yagi T, Mitomo H, Yoshii F, Tamada M (2005) Application of poly (lactic acid) modified by radiation crosslinking. Nucl InstrumMethodsPhys Res B 236:611–616CrossRefGoogle Scholar
  15. 15.
    Elisseeff J, Anseth K, Langer R, Hrkach JS (1997) Synthesis and characterization of photo-cross-linked polymers based on poly (L-lactic acid-co-l-aspartic acid). Macromolecules 30:2182–2184CrossRefGoogle Scholar
  16. 16.
    Liu SQ, Gong WG, Zheng BC (2014) The effect of peroxide cross-linking on the properties of low-density polyethylene. J Macromol Sci B 53:67–77CrossRefGoogle Scholar
  17. 17.
    Wong W, Varrall D (1994) Role of molecular structure on the silane crosslinking of polyethylene: the importance of resin molecular structure change during silane grafting. Polymer 35:5447–5452CrossRefGoogle Scholar
  18. 18.
    Meekum U, Khiansanoi A (2018) PLA and two components silicon rubber blends aiming for frozen foods packaging applications. Results Phys 8:79–88CrossRefGoogle Scholar
  19. 19.
    Si WJ, Yuan WQ, Li YD, Chen YK, Zeng JB (2018) Tailoring toughness of fully biobased poly (lactic acid)/natural rubber blends through dynamic vulcanization. Polym Test 65:249–255CrossRefGoogle Scholar
  20. 20.
    Khajeheian M, Kuusipalo J, Rosling A (2018) Blends of linear and peroxide-modified branched polylactide for extrusion coating. PackagTechnol Sci 31:41–51Google Scholar
  21. 21.
    Khajeheian M, Rosling A (2015) Rheological and thermal properties of peroxide-modified poly (l-lactide)s for blending purposes. J Polym Environ 23:62–71CrossRefGoogle Scholar
  22. 22.
    Hachana N, Wongwanchai T, Chaochanchaikul K, Harnnarongchai W (2017) Influence of crosslinking agent and chain extender on properties of gamma-irradiated PLA. J Polym Environ 25:323–333CrossRefGoogle Scholar
  23. 23.
    Mathew TV, Kuriakose S (2007) Molecular transport of aromatic hydrocarbons through lignin-filled natural rubber composites. Polym Compos 28:15–22CrossRefGoogle Scholar
  24. 24.
    Zosel A, Ley G (1993) Influence of crosslinking on structure, mechanical properties, and strength of latex films. Macromolecules 26:2222–2227CrossRefGoogle Scholar
  25. 25.
    McKenna GB, Flynn KM, Chen Y (1990) Swelling in crosslinked natural rubber: experimental evidence of the crosslink density dependence of χ. Polymer 31:1937–1945CrossRefGoogle Scholar
  26. 26.
    Pojanavaraphan T, Schiraldi DA, Magaraphan R (2010) Mechanical, rheological, and swelling behavior of natural rubber/montmorillonite aerogels prepared by freeze-drying. Appl Clay Sci 50:271–279CrossRefGoogle Scholar
  27. 27.
    Takamura M, Nakamura T, Takahashi T, Koyama K (2008) Effect of type of peroxide on cross-linking of poly (l-lactide). Polym Degrad Stab 93:1909–1916CrossRefGoogle Scholar
  28. 28.
    Olejniczak J, Rosiak J, Charlesby A (1991) Gel/dose curves for polymers undergoing simultaneous cross-linking and scission. Int J Radiat Appl Instrum C Radiat Phys Chem 38:113–118Google Scholar
  29. 29.
    Kader MA, Bhowmick AK (2003) Rheological and viscoelastic properties of multiphase acrylic rubber/fluoroelastomer/polyacrylate blends. Polym Eng Sci 43:975–986CrossRefGoogle Scholar
  30. 30.
    Dunn A (1994) Polymer characterisation. Edited by BJ Hunt and MI James. Blackie (Chapman & Hall), Glasgow, 1993. pp. xiv + 362, price£ 69. ISBN 0‐7514‐0082‐3. Polym Int 33:234-234Google Scholar
  31. 31.
    Giacomin A, Dealy J (1998) Using large-amplitude oscillatory shear. In: Rheological measurement, Springer, DordrechtGoogle Scholar
  32. 32.
    Hadnađev-Dapčević TR, Hadnađev MS, Torbica AM (2009) Utilization of dynamic oscillatory measurements for agar threshold gel concentration and gel strength determination. Food Proc Qual Saf 36:69–73Google Scholar

Copyright information

© Iran Polymer and Petrochemical Institute 2018

Authors and Affiliations

  1. 1.Department of Polymer Engineering and Color TechnologyAmirkabir University of TechnologyTehranIran
  2. 2.Department of ChemistryAmirkabir University of TechnologyTehranIran

Personalised recommendations