Mechanical and Thermal Properties of PLA Melt Blended with High Molecular Weight PEG Modified with Peroxide and Organo-Clay

Abstract:

The thermal and mechanical properties of poly (lactic acid) blended with high molecular weight PEG, i.e. PEG1000 and PEG6000 were compared. The contents of PEG added were 10, 12.5 and 15 % by weight, with respect to PLA. The PLA/PEG blends were modified by addition of organic peroxide in order to induced crosslinking. Addition of organic modified montmorrillonite (Cloisite 30B, C30B) was also performed in order to modify mechanical performance of PLA/PEG blends. C30B was prepared via master batch in PLA. Morphology, crystallization, thermal stability and mechanical properties of the blends were investigated using SEM, DSC, TGA and universal testing macine, respectively. Morphology of cryogenic fracture surface showed smooth brittle surface. PEG1000 well plasticized PLA where as PEG6000 shows better thermal stability and mechanical properties. The presence of PEG induced PLA to perform cold crystallization. T_m in PLA was slightly changed whereas degree of crystallinity of PLA was improved by PEG but slightly decreased by peroxide. The thermal stability of PLA was enhanced with the addtion of PEG6000. The toughening of PLA was confirmed by the increment of elongation at break. The exfoliation of C30B was interfered by the crosslink PLA. Then tensile strength of PLA/PEG/C30B/Luperox101 was then suppressed. The optimum properties, in term of toughening and thermal stability, were found at PEG content of 10 % rather than 15% by weight, for both PEG1000 and PEG6000.

• Periodical: Key Engineering Materials (Volume 751)
• Pages: 337-343
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.751.337
• Online since: August 2017
• Authors: Chanchai Thongpina*, Chaiwat Tippuwanan, Kwanchai Buaksuntear, Teerani Chuawittayawuta
• Keywords: High Molecular Weight PEG, Mechanical Properties, Organo-Clay Cloisite30B, Thermal Properties

References

[1] F. Hassouna, J.M. Raquez, F. Addiego, P. Dubois, V. Toniazzo and D. Ruch, New approach on the development of plasticized polylactide (PLA): Grafting of poly(ethylene glycol) (PEG) via reactive extrusion. European Polymer Journal. 47 (11) (2011).

DOI: 10.1016/j.eurpolymj.2011.08.001

[2] B. Li, F.X. Dong, X.L. Wang, J. Yang, D.Y. Wang and Y.Z. Wang, Organically modified rectorite toughened poly(lactic acid): Nanostructures, crystallization and mechanical properties. European Polymer Journal. 45 (11) (2009) 2996-3003.

DOI: 10.1016/j.eurpolymj.2009.08.015

[3] E. Piorkowska, Z. Kulinski, A. Galeski and R. Masirek, Plasticization of semicrystalline poly(l-lactide) with poly(propylene glycol). Polymer. 47 (20) (2006) 7178-7188.

DOI: 10.1016/j.polymer.2006.03.115

[4] K. Pongtanayut, C. Thongpin and O. Santawitee, The effect of rubber on morphology, thermal properties and mechanical properties of PLA/NR and PLA/ENR blends, Energy Procedia 34 (2013) 888-897.

DOI: 10.1016/j.egypro.2013.06.826

[5] A.K. Mohapatra, S. Mohanty andS.K. Nayak, Effect of PEG on PLA/PEG Blend and Its Nanocomposites: A study of thermo-mechanical and morphological characterization, Polymer Composites. 35 (2014) 283–293.

DOI: 10.1002/pc.22660

[6] K. Sungsanit, N. Kao, S.N. Bhattacharya, Properties of linear poly(lactic acid)/polyethylene glycol, Polymer engineering & science. volume 52 (1) (2012) 108–116.

DOI: 10.1002/pen.22052

[7] A.K. Mohapatra, S. Mohanty and S.K. Nayak, Properties and characterization of biodegradable poly(lactic acid)(PLA)/poly(ethylene glycol) (PEG) and PLA/PEG/organoclay: A study of crystallization kinetics, rheology, and compostability, Thermoplastic Composite Materials, (2014).

DOI: 10.1177/0892705713518812

[8] O. Martin, L. Averous, Poly(lactic acid): Plasticization and properties of biodegradable multiphase systems, Polymer. 42 (2001) 6209-6219.

DOI: 10.1016/s0032-3861(01)00086-6

[9] B.S. Park, J.C. Song, D.H. Park and K.B. Yoon, PLA/Chain-Extended PEG Blends with Improved Ductility, Journal of Applied Polymer Science, 123 (2012) 2360-2367.

DOI: 10.1002/app.34823

[10] N. Fu, G. Li, Q, Zhang, N. Wang and X. Qu, Preparation of functionalized core-shell structured polymer by seeded emulsion polymerization and investigation on toughening poly(butylenes terephthalate), RSC Advances, 4 (2014) 1067-1073.

DOI: 10.1039/c3ra44163f

[11] Y. Huang, C. Zhang, Y. Pan, W. Wang, L. Jiang and Y. Dan, Study on the effect of dicumyl peroxide on structure and properties of poly(lactic acid)/natural rubber blend, Journal of Polyumer Environment, 21 (2013) 375-387.

DOI: 10.1007/s10924-012-0544-0

[12] M. Khodabandelou, M.K.R. Aghjeh and M.M. Mazidj, Fracture toughness and failure mechanisms in unvulcanized and dynamically vulcanized PP/EPDM/MECNT blend-nanocomposites, RSC Advances, 5 (2015) 70817-70831.

DOI: 10.1039/c5ra12087j

[13] N. Lopattananon, J. Julyanon, A. Masa, A. Kaesaman, C. Thongpin and T. Sakai, The role of nanofillers on (natural rubber)/(ethylene vinyl acetate)/clay nanocomposite in blending and foaming, Journal of Vinyl and Additive Technology, 21 (2015).

DOI: 10.1002/vnl.21368

[14] G. Ozkoc and S. Kemaloglu, Morphology, Biodegradability, mechnical and thermal properties of nanocomposite films based on PLA and plasticized PLA.

DOI: 10.1002/app.30772

[15] A. Al-Itry, K. Lamnawar and A. Maazouz, Improvement of thermal stability , rheological and mechanica; properties of PLA, PBAT and their blends by reactive extrusion with functionalized epoxy, Polymer Degradation and Stability, 97 (2012).

DOI: 10.1016/j.polymdegradstab.2012.06.028