Journal of Materials Science

, Volume 50, Issue 11, pp 3942–3955 | Cite as

Accelerated in vitro degradation properties of polylactic acid/phosphate glass fibre composites

  • Reda M. FelfelEmail author
  • Kazi M. Zakir Hossain
  • Andrew J. Parsons
  • Chris D. Rudd
  • Ifty Ahmed
Original Paper


Degradation properties were studied for polylactic acid (PLA) and phosphate glass fibre (40P2O5–24MgO–16CaO–16Na2O–4Fe2O3, denoted as P40) reinforced unidirectional (UD) and randomly mat (RM) PLA composites using phosphate buffer saline (PBS) media over a range of temperatures from 21 to 85 °C. Glass transition and melting temperatures for PLA decreased from 61.3 and 167.4 to 52.7 and 151.6 °C, respectively, and crystallinity increased from 9.2 to 58.3 % during 3 days of degradation period in PBS media at 85 °C. Appearance of sharp crystalline peaks after degradation at higher temperatures which was confirmed via X-ray diffraction analysis was also indicative of increase in crystallinity. However, flexural strength decreased by approximately 20 % (for PLA) and by around 50 % (P40 RM and P40 UD composites) of the initial strength after degradation in PBS at 37 °C. No significant changes in mechanical properties were observed before and after degradation of composites at 21 °C for 56 days. Monomodal molecular weight distribution for the PLA before and after degradation in PBS at 37 °C was replaced by bimodal after degradation at higher temperatures. Arrhenius equation applied for the change in molecular weight of the polymer and composite samples and the obtained degradation activation energies were 85.4, 78.7 and 74.1 kJ mol−1 for PLA within PLA alone, P40 RM and P40 UD composites, respectively. Time prediction was applied to correlate short-term degradation (at elevated temperatures) to the long-term effects (at 37 °C) using both ‘tipping point’ and molecular weight as co-ordinates.


PLLA Flexural Strength Molecular Weight Distribution Degradation Temperature Accelerate Degradation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



The authors would also like to thank Dr. Derek Irvine and Ms. Natasha Birkin for their help with the GPC.


  1. 1.
    Athanasiou KA et al (1998) Orthopaedic applications for PLA-PGA biodegradable polymers. Arthroscopy 14(7):726–737CrossRefGoogle Scholar
  2. 2.
    Pietrzak WS, Kumar M, Eppley BL (2003) The influence of temperature on the degradation rate of LactoSorb copolymer. J Craniofac Surg 14(2):176–183CrossRefGoogle Scholar
  3. 3.
    Li S (1999) Hydrolytic degradation characteristics of aliphatic polyesters derived from lactic and glycolic acids. J Biomed Mater Res 48(3):342–353CrossRefGoogle Scholar
  4. 4.
    Ashammakhi N, Rokkanen P (1997) Absorbable polyglycolide devices in trauma and bone surgery. Biomaterials 18(1):3–9CrossRefGoogle Scholar
  5. 5.
    Lyu SP et al (2007) Kinetics and time–temperature equivalence of polymer degradation. Biomacromolecules 8(7):2301–2310CrossRefGoogle Scholar
  6. 6.
    Agrawal CM et al (1997) Elevated temperature degradation of a 50:50 copolymer of PLA-PGA. Tissue Eng 3(4):345–352CrossRefGoogle Scholar
  7. 7.
    Claes LE et al (1996) New bioresorbable pin for the reduction of small bony fragments: design, mechanical properties and in vitro degradation. Biomaterials 17(16):1621–1626CrossRefGoogle Scholar
  8. 8.
    Deng M et al (2005) Effect of load and temperature on in vitro degradation of poly(glycolide-co-L-lactide) multifilament braids. Biomaterials 26(20):4327–4336CrossRefGoogle Scholar
  9. 9.
    Felfel RM et al (2012) Investigation of crystallinity, molecular weight change, and mechanical properties of PLA/PBG bioresorbable composites as bone fracture fixation plates. J Biomater Appl 26(7):765–789CrossRefGoogle Scholar
  10. 10.
    Felfel RM et al (2011) In vitro degradation, flexural, compressive and shear properties of fully bioresorbable composite rods. J Mech Behav Biomed Mater 4:1462–1472CrossRefGoogle Scholar
  11. 11.
    ASTM Standard D2584-94 (1994) Standard test method for ignition loss of cured reinforced resinsGoogle Scholar
  12. 12.
    Buchanan FJ (ed) (2008) Degradation rate of bioresorbable materials prediction and evaluation. Woodhead Publishing Ltd, Cambridge, p 320Google Scholar
  13. 13.
    Navarro M et al (2005) In vitro degradation behavior of a novel bioresorbable composite material based on PLA and a soluble CaP glass. Acta Biomater 1(4):411–419CrossRefGoogle Scholar
  14. 14.
    Tsuji H, Ikarashi K (2004) In vitro hydrolysis of poly(l-lactide) crystalline residues as extended-chain crystallites: II. Effects of hydrolysis temperature. Biomacromolecules 5(3):1021–1028CrossRefGoogle Scholar
  15. 15.
    Lee TH, Boey FYC, Khor KA (1995) On the determination of polymer crystallinity for a thermoplastic PPS composite by thermal analysis. Compos Sci Technol 53(3):259–274CrossRefGoogle Scholar
  16. 16.
    BS EN ISO 14125 (1998) Fiber reinforced plastic composites—Determination of flexural properties. Geneva, SwitzerlandGoogle Scholar
  17. 17.
    BS EN ISO 1008B (1996) Methods of testing plastics. Part 10: glass reinforced plastics method 1008B: determination of flexural strength on rods made of roving-reinforced resinGoogle Scholar
  18. 18.
    BS EN ISO 10993-13 (2010). Biological evaluation of medical devices. Identification and quantification of degradation products from polymeric medical devicesGoogle Scholar
  19. 19.
    Lyu S, Untereker D (2009) Degradability of polymers for implantable biomedical devices. Int J Mol Sci 10(9):4033–4065CrossRefGoogle Scholar
  20. 20.
    Han X et al (2010) Analysis of degradation data of poly(l-lactide–co-l, d-lactide) and poly(l-lactide) obtained at elevated and physiological temperatures using mathematical models. Acta Biomater 6(10):3882–3889CrossRefGoogle Scholar
  21. 21.
    Tsuji H, Tsuruno T (2010) Accelerated hydrolytic degradation of poly(l-lactide)/poly(d-lactide) stereocomplex up to late stage. Polym Degrad Stab 95(4):477–484CrossRefGoogle Scholar
  22. 22.
    Lee W-K, Iwata T, Gardella JA (2005) Hydrolytic behavior of enantiomeric poly(lactide) mixed monolayer films at the air/water interface: stereocomplexation effects. Langmuir 21(24):11180–11184CrossRefGoogle Scholar
  23. 23.
    Xu L, Crawford K, Gorman CB (2011) Effects of temperature and pH on the degradation of poly(lactic acid) brushes. Macromolecules 44(12):4777–4782CrossRefGoogle Scholar
  24. 24.
    Weir N et al (2004) Degradation of poly-L-lactide. Part 2: increased temperature accelerated degradation. Proc Inst Mech Eng [H] 218(5):321–330CrossRefGoogle Scholar
  25. 25.
    Weir N et al (2004) Degradation of poly-L-lactide. Part 1: in vitro and in vivo physiological temperature degradation. Proc Inst Mech Eng [H] 218(5):307–319CrossRefGoogle Scholar
  26. 26.
    Yuan X, Mak AFT, Yao K (2002) Comparative observation of accelerated degradation of poly(l-lactic acid) fibres in phosphate buffered saline and a dilute alkaline solution. Polym Degrad Stab 75(1):45–53CrossRefGoogle Scholar
  27. 27.
    Li S, Garreau H, Vert M (1990) Structure–property relationships in the case of the degradation of massive poly(α-hydroxy acids) in aqueous media. J Mater Sci Mater Med 1(4):198–206. doi: 10.1007/BF00701077 CrossRefGoogle Scholar
  28. 28.
    Li SM, Garreau H, Vert M (1990) Structure–property relationships in the case of the degradation of massive aliphatic poly-(α-hydroxy acids) in aqueous media. J Mater Sci Mater Med 1(3):123–130CrossRefGoogle Scholar
  29. 29.
    Hakkarainen M, Albertsson A-C, Karlsson S (1996) Weight losses and molecular weight changes correlated with the evolution of hydroxyacids in simulated in vivo degradation of homo- and copolymers of PLA and PGA. Polym Degrad Stab 52(3):283–291CrossRefGoogle Scholar
  30. 30.
    Li S, McCarthy S (1999) Further investigations on the hydrolytic degradation of poly (DL-lactide). Biomaterials 20(1):35–44CrossRefGoogle Scholar
  31. 31.
    Karbhari VM (2004) E-glass/vinylester composites in aqueous environments: effects on short-beam shear strength. J Compos Constr 8(2):148–156CrossRefGoogle Scholar
  32. 32.
    Straub A, Slivka M, Schwartz P (1997) A study of the effects of time and temperature on the fiber/matrix interface strength using the microbond test. Compos Sci Technol 57(8):991–994CrossRefGoogle Scholar
  33. 33.
    Chin JW, Hughes WL, Signor A (2001) Elevated temperature aging of glass fiber reinforced vinyl ester and isophthalic polyester composites in water, salt water, and concrete pore solution. In: American Society for Composites, 16th technical conference. Proceedings. September 9–12, 2001, Blacksburg, pp 1–12Google Scholar
  34. 34.
    Antheunis H et al (2010) Autocatalytic equation describing the change in molecular weight during hydrolytic degradation of aliphatic polyesters. Biomacromolecules 11(4):1118–1124CrossRefGoogle Scholar
  35. 35.
    Ehrenfried LM, Farrar D, Cameron RE (2009) Degradation properties of co-continuous calcium-phosphate-polyester composites. Biomacromolecules 10(7):1976–1985CrossRefGoogle Scholar
  36. 36.
    Zimmerman MC et al (1991) The design and analysis of laminated degradable composite bone plates for fracture fixation. In: High-Tech Fibrous Materials. American Chemical Society, Washington, DC, pp 132–148CrossRefGoogle Scholar
  37. 37.
    Arnold C et al (2010) Design optimisation of carbon fibre epoxy composites operating in humid atmospheres. In: Composites UK—10th annual conference: innovation in composites 2010. Birmingham, UKGoogle Scholar
  38. 38.
    Bunsell AR, Renard J (2005) Fundamentals of fibre reinforced composite materials. IOP Publishing Ltd., UKGoogle Scholar
  39. 39.
    Litherland KL, Oakley DR, Proctor BA (1981) The use of accelerated ageing procedures to predict the long term strength of GRC composites. Cem Concr Res 11(3):455–466CrossRefGoogle Scholar
  40. 40.
    Deng M et al (2008) A study on in vitro degradation behavior of a poly(glycolide-co-l-lactide) monofilament. Acta Biomater 4(5):1382–1391CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2015

Authors and Affiliations

  • Reda M. Felfel
    • 1
    • 2
    Email author
  • Kazi M. Zakir Hossain
    • 1
  • Andrew J. Parsons
    • 1
  • Chris D. Rudd
    • 1
  • Ifty Ahmed
    • 1
  1. 1.Division of Materials, Mechanics and Structures, Faculty of EngineeringUniversity of NottinghamNottinghamUK
  2. 2.Physics Department, Faculty of ScienceMansoura UniversityMansouraEgypt

Personalised recommendations