In recent years, poly(lactic acid) (PLA) foams have drawn considerable attention worldwide due to their environmental friendliness and excellent biocompatibility. However, it was a big challenge to prepare PLA foams with high volume expansion ratio owing to their poor crystallization properties and melt strength. In this work, the random copolymer of ethylene and glycidyl methacrylate as an efficient chain extender (CE) was chosen and employed to improve the crystallization behaviors and foamability of PLA. The chain extension reaction between PLA and CE was proved by torque curves, Fourier transform infrared spectra, gel fraction, and intrinsic viscosity measurements. Differential scanning calorimetry results and polarized optical microscope images showed that the crystallinity and spherocrystal number of various PLA samples increased notably as well as their spherocrystal size decreased with the CE content increasing. The viscoelasticity of various PLA samples was improved by the increment in the CE content. Various PLA samples were foamed by a batch foaming method at different foaming temperature with supercritical CO2 to research the influence of crystallization behaviors and/or rheological properties on the foaming behaviors of PLA. At the high foaming temperature, the cell density and volume expansion ratio (VER) of various PLA foams were affected by rheological properties significantly and their highest VER could reach to 42.41 ± 0.01 times. At the low foaming temperature, the cellular morphology of various PLA foams was improved notably, due to the increased melt strength induced by the cooling and the generation of crystallization region.
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Kuang T, Chen F, Chang L, Zhao Y, Fu D, Gong X, Peng X (2017) Facile preparation of open-cellular porous poly (L-lactic acid) scaffold by supercritical carbon dioxide foaming for potential tissue engineering applications. Chem Eng J 307:1017–1025
Zhou X, Yang R, Wang B, Chen K (2019) Development and characterization of bilayer films based on pea starch/polylactic acid and use in the cherry tomatoes packaging. Carbohyd Polym 222:114912
Kuang T, Chang L, Chen F, Sheng Y, Fu D, Peng X (2016) Facile preparation of lightweight high-strength biodegradable polymer/multi-walled carbon nanotubes nanocomposite foams for electromagnetic interference shielding. Carbon 105:305–313.
Geng L, Li L, Mi H, Chen B, Sharma P, Ma H, Hsiao B, Peng X, Kuang T (2017) Superior impact toughness and excellent storage modulus of poly (lactic acid) foams reinforced by shish-kebab nanoporous structure. ACS Appl Mater Interfaces 9:21071–21076
Wang X, Mi J, Wang J, Zhou H, Wang X (2018) Multiple actions of poly (ethylene octene) grafted with glycidyl methacrylate on the performance of poly (lactic acid). RSC Adv 8:34418
Ding W, Jahani D, Chang E, Alemdar A, Park CB, Sain M (2016) Development of PLA/cellulosic fiber composite foams using injection molding: Crystallization and foaming behaviors. Compos A Appl Sci Manuf 83:130–139
Zhou H, Zhao M, Qu Z, Mi J, Wang X, Deng Y (2018) Thermal and rheological properties of poly (lactic acid)/low-density polyethylene blends and their supercritical CO2. J Polym Environ 26:3564–3573
Di Y, Iannace S, Di Maio E, Nicolais L (2005) Reactively modified poly (lactic acid): Properties and foam processing. Macromol Mater Eng 290:1083–1090
Di Y, Iannace S, Maio ED, Nicolais L (2005) Poly (lactic acid)/organoclay nanocomposites: Thermal, rheological properties and foam processing. J Polym Sci, Part B: Polym Phys 43:689–698
Al-ltry R, Lamnawar K, Maazouz A (2012) Improvement of thermal stability, rheological and mechanical properties of PLA, PBAT and their blends by reactive extrusion with functionalized epoxy. Polym Degrad Stab 97:1898–1914
Ju J, Peng X, Huang K, Li L, Liu X, Chitrakar C, Chang L, Gu Z, Kuanga T (2019) High-performance porous PLLA-based scaffolds for bone tissue engineering: Preparation, characterization, and in vitro and in vivo evaluation. Polymer 180:121707
Nerkar M, Ramsay J, Ramsay B, Vasileiou A, Kontopoulou M (2015) Improvements in the melt and solid-state properties of poly (lactic acid), poly-3-hydroxyoctanoate and their blends through reactive modification. Polymer 64:51–61
Corre Y, Maazouz A, Duchet J, Reignier J (2011) Batch foaming of chain extended PLA with supercritical CO2: Influence of the rheological properties and the process parameters on the cellular structure. The Journal of Supercritical Fluids 58:177–188
Yu L, Toikka G, Dean K, Bateman S, Nguyen T (2013) Foaming behaviour and cell structure of poly (lactic acid) after various modifications. Polym Int 62:759–765
Mihai M, Huneault M, Favis B (2009) Crystallinity development in cellular poly (lactic acid) in the presence of supercritical carbon dioxide. J Appl Polym Sci 113:2920–2932
Wang J, Zhu W, Zhang H, Park C (2012) Continuous processing of low-density, microcellular poly (lactic acid) foams with controlled cell morphology and crystallinity. Chem Eng Sci 75:390–399
Taki K, Kitano D, Ohshima M (2011) Effect of growing crystalline phase on bubble nucleation in poly (L-lactide)/CO2 batch foaming. Ind Eng Chem Res 50:3247–3252
Li Y, Mi J, Fu H, Zhou H, Wang X (2019) Nanocellular foaming behaviors of chain-extended poly (lactic acid) induced by isothermal crystallization. ACS Omega 4:12512–12523
Tiwary P, Park C, Kontopoulou M (2017) Transition from microcellular to nanocellular PLA foams by controlling viscosity, branching and crystallization. Eur Polymer J 91:283–296
Kuang T, Mi H, Fu D, Jing X, Chen B, Mou W, Peng X (2015) Fabrication of poly (lactic acid)/graphene oxide foams with highly oriented and elongated cell structure via unidirectional foaming using supercritical carbon dioxide. Ind Eng Chem Res 54:758–768
Song J, Mi J, Zhou H, Wang X, Zhang Y (2018) Chain extension of poly (butylene adipate-co-terephthalate) and its microcellular foaming behaviors. Polym Degrad Stab 157:143–152
Wang X, Mi J, Zhou H, Wang X (2018) Transition from microcellular to nanocellular chain extended poly (lactic acid)/hydroxyl-functionalized graphene foams by supercritical CO2. J Mater Sci 54:3863–3877
Huang A, Kharbas H, Ellingham T, Mi H, Turng L, Peng X (2017) Mechanical properties, crystallization characteristics, and foaming behavior of polytetrafluoroethylene-reinforced poly(lactic acid) composites. Polym Eng Sci 57:570–580.
Liu H, Song W, Chen F, Guo L, Zhang J (2011) Interaction of microstructure and interfacial adhesion on impact performance of polylactide (PLA) ternary blends. Macromolecules 44:1513–1522
Zhang C, Wang W, Huang Y, Pan Y, Jiang L, Dan Y, Luo Y, Peng Z (2013) Thermal, mechanical and rheological properties of polylactide toughened by expoxidized natural rubber. Mater Des 45:198–205
Kasaai M (2012) Dilute solution properties and degree of chain branching for dextran. Carbohydr Polym 88:373–381
Huang A, Wang H, Peng X, Turng L (2018) Polylactide/thermoplastic polyurethane/polytetrafluoroethylene nanocomposites with in situ fibrillated polytetrafluoroethylene and nanomechanical properties at the interface using atomic force microscopy. Polym Testing 67:22–30
Wang X, Li Y, Jiao Y, Zhou H, Wang X (2019) Microcellular foaming behaviors of poly (lactic acid)/low-density polyethylene blends induced by compatibilization effect. J Polym Environ 27:1721–1734
Qu Z, Yin D, Zhou H, Wang X, Zhao S (2019) Cellular morphology evolution in nanocellular poly (lactic acid)/thermoplastic polyurethane blending foams in the presence of supercritical N2. Eur Polym J 116:291–301
Zhang K, Wang Y, Jiang J, Wang X, Hou J, Sun S, Li Q (2019) Fabrication of highly interconnected porous poly(ɛ-caprolactone) scaffolds with supercritical CO2 foaming and polymer leaching. J Mater Sci 54:5112–5126
Sun S, Li Q, Zhao N, Jiang J, Zhang K, Hou J, Wang X, Liu G (2018) Preparation of highly interconnected porous poly (ε-caprolactone)/poly (lactic acid) scaffolds via supercritical foaming. Polym Adv Technol 29:3065–3074
Chiou K, Chang F (2015) Reactive compatibilization of polyamide-6 (PA 6)/polybutylene terephthalate (PBT) blends by a multifunctional epoxy resin. J Polym Sci, Part B 38:23–33
Wang Z, Ding X, Zhao M, Wang X (2017) A cooling and two-step depressurization foaming approach for the preparation of modified HDPE foam with complex cellular structure. J Supercrit Fluids 125:22–30
Azizi H, Morshedian J, Barikani M, Wagner M (2011) Correlation between molecular structure parameters and network properties of silane-grafted and moisture cross-linked polyethylenes. Adv Polym Technol 30:286–300
Kijchavengkul T, Auras R, Rubino M, Alvarado E, Jose R, Rosales J (2010) Atmospheric and soil degradation of aliphatic-aromatic polyester films. Polym Degrad Stab 95:99–107
Milovanovic S, Markovic D, Mrakovic A, Kuska R, Zizovic I, Frerich S, Ivanovic J (2019) Supercritical CO2-ssisted production of PLA and PLGA foams for controlled thymol release. Mater Sci Eng C 99:394–404
Lagaron J, Lopez-Rubio A, Jose F (2016) Bio-based packaging. J Appl Polym Sci 133:42971
Gu X, Huang X, Wei H, Tang X (2011) Synthesis of novel epoxy-group modified phosphazene-containing nanotube and its reinforcing effect in epoxy resin. Eur Polymer J 47:903–910
Xue B, He H, Zhu Z, Li J, Huang Z, Wang G, Chen M, Zhan Z (2018) A facile fabrication of high toughness poly (lactic acid) via reactive extrusion with poly (butylene succinate) and ethylene-methyl acrylate-glycidyl methacrylate. Polymers 10:1401
Alokour M, Yilmaz E (2019) Photoinitiated synthesis of poly (poly (ethylene glycol) methacrylate-co-diethyl amino ethyl methacrylate) superabsorbent hydrogels for dye adsorption. J Appl Polym Sci 136:47707
Yin D, Mi J, Zhou H, Wang X, Fu H (2019) Microcellular foaming behaviors of chain extended poly (butylenes succinate)/polyhedral oligomeric silsesquioxane composite induced by isothermal crystallization. Polym Degrad Stab 167:228–240
Buccella M, Dorigato A, Pasqualini E, Caldara M, Fambri L (2014) Chain extension behavior and thermo-mechanical properties of polyamide 6 chemically modified with 1,1′-carbonyl-bis-caprolactam. Polym Eng Sci 54:158–165
Yang Y, Li X, Zhang Q, Xia C, Chen C, Chen X, Yu P (2019) Foaming of poly (lactic acid) with supercritical CO2: The combined effect of crystallinity and crystalline morphology on cellular structure. J Supercrit Fluids 145:122–132
Nofar M, Park C (2014) Poly (lactic acid) foaming. Prog Polym Sci 39:1721–1741
Hermansson E, Schuster E, Lindgren L, Altskar A, Strom A (2016) Impact of solvent quality on the network strength and structure of alginate gels. Carbohyd Polym 144:289–296
Jahani Y, Ghetmiri M, Vaseghi M (2015) The effects of long chain branching of polypropylene and chain extension of poly (ethylene terephthalate) on the thermal behavior, rheology and morphology of their blends. RSC Advances 5:21620–21628
Auras R, Harte B, Selke S (2004) An overview of polylactides as packaging materials. Macromol Biosci 4:835–864
Eslami H, Kamal M (2013) Effect of a chain extender on the rheological and mechanical properties of biodegradable poly (lactic acid)/poly [(butylene succinate)-co-adipate] blends. J Appl Polym Sci 129:2418–2428
Villani V, Lavallata V (2017) Unusual rheological properties of lightly crosslinked polydimethylsiloxane. Macromol Chem Phys 218:1700037
Najafi N, Heuzey M, Carreau P, Therriault D, Park C (2014) Rheological and foaming behavior of linear and branched polylactides. Rheol Acta 53:779–790
Nofar M, Zhu WL, Park C, Randall J (2011) Crystallization kinetics of linear and long-chain-branched polylactide. Ind Eng Chem Res 50:13789–13798
This work was supported by the National Science Foundation of China (51703004 and 51673004) and the Natural Science Foundation of Beijing (2164058 and 2162012).
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Li, Y., Zhou, H., Wen, B. et al. A Facile and Efficient Method for Preparing Chain Extended Poly(lactic acid) Foams with High Volume Expansion Ratio. J Polym Environ 28, 17–31 (2020) doi:10.1007/s10924-019-01572-2
- Poly (lactic acid)
- Chain extension
- Supercritical CO2
- Crystallization behaviors
- Rheological properties