Abstract
Poly(l-lactic acid) (PLLA)/graphene nanoplatelets (GnP) nanocomposites were prepared through solvent casting and coagulation methods. The better dispersion of graphene was achieved by ultrasounds and its effect on crystallinity, thermomechanical and electrical properties of PLLA were studied and compared in both methods. Differential scanning calorimetry (DSC) was used to investigate the crystallinity of PLLA and its composites. Field emission gun scanning electron microscope (FEG-SEM) and wide-angle X-ray scattering (WAXS) were employed to characterize the microstructure of PLLA crystallites. Dynamic mechanical thermal analysis (DMTA) was performed to study the thermomechanical properties of the nanocomposites. FEG-SEM images illustrated finer dispersion of GnP in samples obtained by coagulation method with respect to solvent casting method. Graphene imparted higher electrical conductivity to nanocomposites obtained by solvent casting under ultrasound due to better formation of graphene network. DSC thermograms and their resulting data showed positive effects of GnP on crystallization kinetics of PLLA in both methods enhanced by the nucleating effect of graphene particles. Meanwhile, the effect of GnP, as nucleating agent, was more prominent in samples produced by coagulation method without utilization of ultrasounds. WAXS patterns represented the same characteristic peaks of PLLA in nanocomposite specimens suggesting similar crystalline structure of PLLA in presence of graphene, and the intensified peaks of nanocomposites compared to neat PLLA confirmed the DSC results regarding its improved crystallinity. Graphene increased storage modulus in rubbery region and glass transition temperature of nanocomposites in the coagulation method due to restricted mobility of PLLA chains.
Similar content being viewed by others
References
Kim H, Abdala AA, Macosko CW (2010) Graphene/polymer nanocomposites. Macromolecules 43:6515–6530
Georgakilas V, Otyepka M, Bourlinos AB, Chandra V, Kim N, Kemp KC, Hobza P, Zboril R, Kim KS (2012) Functionalization of graphene: covalent and non-covalent approaches, derivatives and applications. Chem Rev 112:6156–6214
Tang Z, Kang H, Wei Q, Guo B, Zhang L, Jia D (2013) Incorporation of graphene into polyester/carbon nanofibers composites for better multi-stimuli responsive shape memory performances. Carbon 64:487–498
Wang H, Qiu Z (2011) Crystallization behaviors of biodegradable poly(l-lactic acid)/graphene oxide nanocomposites from the amorphous state. Thermochim Acta 526:229–236
Pan P, Zhu B, Kai W, Dong T, Inoue Y (2008) Polymorphic transition in disordered poly(l-lactide) crystals induced by annealing at elevated temperatures. Macromolecules 41:4296–4304
Norazlina H, Kamal Y (2015) Graphene modifications in polylactic acid nanocomposites: a review. Polym Bull 72:931–961
Lim L-T, Auras R, Rubino M (2008) Processing technologies for poly(lactic acid). Prog Polym Sci 33:820–852
Lasprilla AJR, Martinez GAR, Lunelli BH, Jardini AL, Filho RM (2012) Poly-lactic acid synthesis for application in biomedical devices: a review. Biotechnol Adv 30:321–328
Chen J, Zhang ZX, Huang WB, Li JI, Yang JH, Wang Y, Zhou ZW, Zhang JH (2015) Carbon nanotube network structure induced strain sensitivity and shape memory behavior changes of thermoplastic polyurethane. Mater Des 69:105–113
Cao Y, Feng J, Wu P (2010) Preparation of organically dispersible graphene nanosheet powders through a lyophilization method and their poly(lactic acid) composites. Carbon 48:3834–3839
Murariu M, Dechief AL, Bonnaud L, Paint Y, Gallos A, Fontaine G, Bourbigot S, Dubois P (2010) The production and properties of polylactide composites filled with expanded graphite. Polym Degrad Stab 95:889–900
Sabzi M, Jiang L, Liu F, Ghasemi I, Atai M (2013) Graphene nanoplatelets as polylactic acid modifier: linear rheological behavior and electrical conductivity. J Mater Chem A 1:8253–8261
Pinto AM, Moreira S, Gonçalves IC, Gama FM, Mendes AM, Magalhaes FD (2013) Biocompatibility of poly(lactic acid) with incorporated graphene-based materials. Colloid Surf B 104:229–238
Manafi P, Ghasemi I, Karrabi M, Azizi H (2014) Effect of graphene nanoplatelets on crystallization kinetics of poly(lactic acid) effect of graphene nanoplatelets on crystallization kinetics of poly(lactic acid). Soft Mater 12:433–444
Manafi P, Ghasemi I, Karrabi M, Azizi H, Manafi MR, Ehsaninamin P (2015) Thermal stability and thermal degradation kinetics (model-free kinetics) of nanocomposites based on poly(lactic acid)/graphene: the influence of functionalization. Polym Bull 72:1095–1112
Hielscher T (2005) Ultrasonic production of nano-size dispersions and emulsions. In: 1st work, Nano Technology Transfer ENS Paris
Garlotta D (2002) A literature review of poly(lactic acid). J Polym Environ 9:63–84
Tkalya EE, Ghislandi M, de With G, Koning CE (2012) The use of surfactants for dispersing carbon nanotubes and graphene to make conductive nanocomposites. Curr Opin Colloid Interf Sci 17:225–232
Chen Y, Yao X, Pan Z, Gu Q (2011) Preparation and isothermal crystallization behavior of poly(lactic acid)/graphene nanocomposites. Adv Mater Res 284–286:246–252
Nabipour Chakoli A, Sui J, Amirian M, Cai W (2011) Crystallinity of biodegradable polymers reinforced with functionalized carbon nanotubes. J Polym Res 18:1249–1259
Huang H-D, Ren P-G, Xu J-Z, Xu L, Zhong GJ, Hsiao BS, Li ZM (2014) Improved barrier properties of poly(lactic acid) with randomly dispersed graphene oxide nanosheets. J Membr Sci 464:110–118
Xiao H, Yang L, Ren X, Jiang T, Yeh JT (2010) Kinetics and crystal structure of poly(lactic acid) crystallized nonisothermally: effect of plasticizer and nucleating agent. Polym Compos 31:2057–2068
Yan B, Gu S, Zhang Y (2013) Polylactide-based thermoplastic shape memory polymer nanocomposites. Eur Polym J 49:366–378
Mavinakuli P, Wei S, Wang Q, Karki AB, Dhage S, Wang Z, Young DP, Guo Z (2010) Polypyrrole/silicon carbide nanocomposites with tunable electrical conductivity. J Phys Chem C 114:3874–3882
Xu J, Shi W, Pang W (2006) Synthesis and shape memory effects of Si–O–Si cross-linked hybrid polyurethanes. Polymer 47:457–465
Wunderlich B (2005) Basics of thermal analysis. Thermal analysis of polymeric materials. Springer, Berlin
Landel RF, Nielsen LE (1993) Mechanical properties of polymers and composites, 2nd edn. Taylor & Francis, New York
Huang X, Jiang P, Kim C, Ke Q, Wang G (2008) Preparation, microstructure and properties of polyethylene aluminum nanocomposite dielectrics. Compos Sci Technol 68:2134–2140
Acknowledgments
The authors would like to thank Prof. Roberto Giovanardi for his help on electrical conductivity measurements and Dr. Mauro Zapparoli (for FEG-SEM images) and Dr. Massimo Tonelli (for WAXD analysis) in the CIGS center of University of Modena and Reggio Emillia.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Lashgari, S., Karrabi, M., Ghasemi, I. et al. Graphene nanoplatelets dispersion in poly(l-lactic acid): preparation method and its influence on electrical, crystallinity and thermomechanical properties. Iran Polym J 25, 193–202 (2016). https://doi.org/10.1007/s13726-015-0413-5
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s13726-015-0413-5