Publicado

2021-03-25

Ácido L-poliláctico (PLA) y nanotubos de carbono de pared múltiple (NTCPM) con potenciales aplicaciones industriales

L-polylactic acid (PLA) and multi-walled carbon nanotubes (CNTMW) with potential industrial applications

Ácido L-polilático (PLA) e nanotubos de carbono de paredes múltiplas (NTCPM) com possíveis aplicações industriais

DOI:

https://doi.org/10.15446/rev.colomb.quim.v50n1.89838

Palabras clave:

ácido poliláctico, nanotubos de carbono, nanomateriales compuestos, nanomateriales, polímeros biodegradables (es)
polylactic acid, carbon nanotubes, nanocomposites, nanomaterials, biodegradable polymers. (en)
ácido polilático, nanotubos de carbono, nanocompósitos, nanomateriais, polímeros biodegradáveis. (pt)

Autores/as

  • José Roberto Vega-Baudrit Laboratorio Nacional de Nanotecnología LANOTEC https://orcid.org/0000-0002-2002-1744
  • Fabian Murillo Vargas Universidad Nacional de Costa Rica
  • Guillermo Jiménez Villalta Universidad Nacional de Costa Rica
  • Marianelly Esquivel Alfaro Universidad Nacional de Costa Rica

En términos generales, es bien conocida la cualidad que poseen algunos polímeros de cambiar sus propiedades físicas y químicas finales mediante la adición de nanopartículas a la matriz polimérica para producir un material compuesto (MC). Esta investigación está basada en la obtención de un MC a partir de ácido poliláctico (PLA) y nanotubos de carbono de pared múltiple (NTCPM), muy empleado en la industria del envasado y dispositivos biomédicos, con el fin de ampliar su perfil industrial.

Se desarrollaron cuatro mezclas de PLA y NTCPM, y se empleó polietilenglicol (PEG) como plastificante. Se evaluaron sus propiedades morfológicas, térmicas, mecánicas, termo-mecánicas, espectroscópicas, ángulo de contacto y cristalográficas. Se observó que los MCs presentaron degradación térmica a temperaturas inferiores a la matriz sin NTCPM, así como un aumento en el módulo de flexión y tensión en algunas de las muestras. Así mismo, se observó que los NTCPM pueden aumentar la cristalinidad del material y que, en algunos casos, se incrementa su rigidez, actuando como un aditivo útil para aplicaciones de mayor esfuerzo mecánico que la matriz.

Del efecto de agregar PEG en los MC, se determinó que los NTCPM no restringen la movilidad de las cadenas poliméricas y se da un efecto plastificante, lo que permite mayor movilidad de la zona amorfa de las cadenas de polímero, como indica la literatura consultada. Finalmente, se concluyó que a mayores contenidos de NTCPM, se generan mejores valores en el módulo de flexión, esfuerzo máximo de flexión, módulo de elongación, esfuerzo de carga máxima y esfuerzo de ruptura, entre otras propiedades evaluadas.

The quality of some polymers to change their final physical and chemical properties by adding nanoparticles to the polymer matrix to produce a composite material (MC) is well known. This research is based on obtaining a MC from polylactic acid (PLA) and multi-walled carbon nanotubes (CNTMW), widely used in the packaging industry and biomedical devices, in order to expand its industrial profile.

Four mixtures of PLA and CNTMW were developed, and polyethylene glycol (PEG) was used as a plasticizer. Their morphological, thermal, mechanical, thermo-mechanical, spectroscopic, contact angle, and crystallographic properties were evaluated. It was observed that the composites showed thermal degradation at temperatures below the matrix without CNTMW, as well as an increase in the modulus of flexion and tension in some of the samples. Likewise, it was observed that the CNTMW can increase the crystallinity of the material and that, in some cases, its rigidity is increased, acting as a useful additive for applications of greater mechanical stress than the matrix.

From the effect of adding PEG in the composites, the CNTMW do not restrict the mobility of the polymer chains and a plasticizing effect occurs, which allows greater mobility of the amorphous zone of the polymer chains. In general terms, it was concluded that at higher CNTMW contents, better values ​​were generated in the flexural modulus, maximum flexural stress, elongation modulus, maximum load stress and rupture stress, among other evaluated properties.

Alguns polímeros têm a propriedade de alterar suas propriedades físicas e químicas finais, adicionando nanopartículas à matriz polimérica para produzir um composto. Esta pesquisa baseia-se na obtenção de composto partir de ácido polilático (PLA) e nanotubos de carbono de paredes múltiplas (MWCNT), amplamente utilizado na indústria de embalagens e dispositivos biomédicos, a fim de expandir seu perfil industrial.

Foram desenvolvidas quatro misturas de PLA e MWCNT e o polietilenoglicol (PEG) foi usado como plastificante. Foram avaliadas suas propriedades morfológicas, térmicas, mecânicas, termo-mecânicas, espectroscópicas, ângulo de contato e cristalográficas. Observou-se que os compostos apresentaram degradação térmica em temperaturas abaixo da matriz sem MWCNT, além de aumento no módulo de flexão e tensão em algumas das amostras. Da mesma forma, observou-se que o MWCNT pode aumentar a cristalinidade do material e que, em alguns casos, sua rigidez é aumentada, atuando como um aditivo útil para aplicações de maior tensão mecânica que a matriz.

A partir do efeito da adição de PEG nos compostos, determinou-se que o MWCNT não restringe a mobilidade das cadeias poliméricas e ocorre um efeito plastificante, que permite maior mobilidade da zona amorfa das cadeias poliméricas. Em termos gerais, concluiu-se que, com maiores teores de MWCNT, melhores valores foram gerados no módulo de flexão, tensão máxima de flexão, módulo de alongamento, tensão de carga máxima e tensão de ruptura, entre outras propriedades avaliadas.

Descargas

Los datos de descargas todavía no están disponibles.

Citas

M. Jamshidian, E. Tehrany, M. Imran, M. Jacquot & S. Desobry, “Poly-Lactic Acid: Production, Applications, Nanocomposites, and Release Studies”, Comprehensive Reviews in Food Science and Food Safety, n.o 9, pp. 552-571, 2010. DOI: https://doi.org/10.1111/j.1541-4337.2010.00126.x

Natureworksllc.com. 2020. Natureworks | About Natureworks. [Online] Available: https://www.natureworksllc.com/About-NatureWorks [Accessed: 8-Aug-2020].

O. Wolf, Techno-economic feasibility of large-scale production of bio-based polymers in Europe. Institute for Prospective Technological Studies, Madrid: European Communities, 2005, pp. 50-64.

J. Lim, S. Kim, S. Lim & Y. Kim, “Improvement of flexural strengths of poly(L-lactic acid) by solid-state extrusión, 2: extrusión through rectangular die”, Macromolecular Materials and Engineering, n.o 288, pp. 50-57, 2003. DOI: https://doi.org/10.1002/mame.200290033

T. Furukawa, H. Sato, R. Murakami, J. Zhang, Y. Duan, I. Noda, S. Ochiai & Y. Ozaki, “Structure, dispersibility, and crystallinity of poly(hydroxybutyrate)/poly(L-lactic acid) blends studied by FT-IR microspectroscopy and differential scanning calorimetry”, Macromolecules, n.o 38, pp. 6445-6454, 2005. DOI: https://doi.org/10.1021/ma0504668

S. Vainionpaa, P. Rokkanen & P. Tormall, “Surgical application of biodegradable polymers in human tissues”, Prog Polym Sci., n.o 14, pp. 679-716, 1989. DOI: https://doi.org/10.1023/B:BILE.0000004398.38799.29

T. Ohkita & S. Lee S., “Thermal degradation and biodegradability of poly(lacticacid)/cornstarch biocomposites”, Journal of Applied Polymer Science, n.o 100, pp. 3009-3017, 2006. DOI: https://doi.org/10.1002/app.23425

D. Williams, “Enzymatic hydrolysis of polylactic acid”, Engineering in Medicine, n.o 10, pp. 5-7, 1981. DOI: https://doi.org/10.1243/EMED_JOUR_1981_010_004_02

Y. Oda, A. Yonetsu, T. Urakami & K. Tonomura, “Degradation of polylactide by commercial proteases”, Journal of Polymers and the Environment, n.o 8, pp. 29-32, 2000. DOI: https://doi.org/10.1023/A:1010120128048

H. Lim, T. Raku & Y. Tokiwa, “Hydrolysis of polyesters by serine proteases”, Biotechnology Letters, n.o 27, pp. 459-64, 2005. DOI: https://doi.org/10.1007/s10529-005-2217-8

K. Masaki, N. Kamini, H. Ikeda & H. Iefuji, “Cutinase-like enzyme from the yeast Cryptococcus sp. strain. S-2 hydrolyses polylactic acid and other biodegradable plastics”, Applied Environmental Microbiology, n.o 7, pp. 7548-7550, 2005. DOI: https://dx.doi.org/10.1128%2FAEM.71.11.7548-7550.2005

P. Jiménez, M. Sibaja & J. Vega-Baudrit, “Síntesis y caracterización de poli (ácido L-láctico) por Policondensación Directa Obtenido del Fermento de Desechos Agroindustriales de Banano (Musa Acuminata Aaa Variedad Cavendish Cultivar Gran Naine) en Costa Rica”, Revista Iberoamericana de Polímeros, n.o 13, pp. 52-59, 2013.

Cdn.intechopen.com, 2020. [Online]. Available: http://cdn.intechopen.com/pdfs-wm/26368.pdf. [Accessed: 08-Aug-2020].

YTC America Inc 2020. [Online]. Available: http://www.ytca.com/biodegradable_plastics_and_composites. [Accessed: 08-Aug-2020].

S. Ramaswamy, “Study of Morphological, Mechanical and Electrical properties of Electrospun Poly(lactic acid) Nanofibers incorporated with Multiwalled Carbon Nanotubes as a Function of Thermal Bonding”, Repository.lib.ncsu.edu, 2020. [Online]. Available: http://repository.lib.ncsu.edu/ir/bitstream/1840.16/656/1/etd.pdf. [Accessed: 08-Aug-2020].

A. Abdal-hay, S. Park, G. Abdel-Jaber & J. Lim, “Biodegradable Poly(Lactic Acid)/Multiwalled Carbon Nanotube Nanocomposites Fabrication Using Casting And Hot Press Techniques”, International Journal of Innovative Research in Science, Engineering and Technology, n.o 2, pp. 7976-7981, 2013. ISSN: 2319-8753.

B. Chieng, N. Ibrahim, W. Yunus & M. Hussein, “Poly(lactic acid)/Poly(ethylene glycol) Polymer Nanocomposites: Effects of Graphene Nanoplatelets”, Polymers, vol. 6, n.o 1, pp. 93-104, 2014. https://doi.org/10.3390/polym6010093

R. Khare & S. Bose, “Carbon Nanotube Based Composites- A Review”, Journal of Minerals & Materials Characterization & Engineering, n.o 4, pp. 31-46, 2005. DOI: http://dx.doi.org/10.4236/jmmce.2005.41004

B. Kumar, M. Castro, J. Feller, “ Poly (lactic acid)-multi-wall carbon nanotube conductive biopolymer nanocomposite vapour sensors”, Sensors and Actuators B: Chemical, n.o 161, pp. 621-628, 2012. DOI: https://www.researchgate.net/deref/http%3A%2F%2Fdx.doi.org%2F10.1016%2Fj.snb.2011.10.077

R. Moradian & A. Fathalian, “Effects of inter wall hopping on the electronic properties of double-wall carbon nanotubes”, Solid State Communications, n.o 149, pp. 491-495, 2009. DOI: https://www.researchgate.net/deref/http%3A%2F%2Fdx.doi.org%2F10.1016%2Fj.ssc.2008.12.028

M. Obarzanek-Fojt, Y. Elbs-Glatz, E. Lizundia, L. Diener, S. Sarasua, A. Bruinink, “From implantation to degradation — are poly (L-lactide)/multiwall carbon nanotube composite materials really cytocompatible?”, Nanomedicine: Nanotechnology, Biology, and Medicine, n.o 10, pp. 1041-1051, 2014. DOI: http://dx.doi.org/10.1016/j.nano.2013.12.012

F. Mai, Y. Habibi, J. Raquez, P. Dubois, J. Feller, T. Peijs & E. Bilotti, “Poly(lactic acid)/carbon nanotube nanocomposites with integrated degradation sensing”, Polymer, n.o 54, pp. 6818-6823, 2013. DOI: http://dx.doi.org/10.1016/j.polymer.2013.10.035

A. Coats & J. Redfern, “Thermogravimetric Analysis: A review”, The Analyst (Royal Society of Chemistry), n.o 88, pp. 906-924, 1963. DOI: http://dx.doi.org/10.1016/j.polymer.2013.10.035

“ASTM E1131 - 20 Standard Test Method for Compositional Analysis by Thermogravimetry”, Astm.org, 2020. [Online]. Available: http://www.astm.org/Standards/E1131.htm. [Accessed: 08-Aug-2020].

T. DeBorde, J. Joiner, M. Leyden & E. Minot, “Identifying Individual Single-Walled and Double-Walled Carbon Nanotubes by Atomic Force Microscopy”, Nanoletters, n.o 8, pp. 3568-3571, 2008. DOI: https://doi.org/10.1021/nl801106p

M. Zdrojekl, W. Gebicki1, C. Jastrzebski1, C. Melin & A. Huczko, “Studies of multiwall carbon nanotubes using Raman spectroscopy and atomic force microscopy”, Solide State Phenomena, n.o 99, pp. 265-269, 2004. DOI: https://doi.org/10.4028/www.scientific.net/SSP.99-100.265

G. Maurin, I. Stepanek, P. Bernier, J. Colomer, J. Nagy & F. Henn, “Segmented and opened multi-walled carbon nanotubes”, Carbon, n.o 39, pp. 1273-1278, 2000. DOI: https://doi.org/10.1016/S0008-6223(00)00250-5

D. Leclere, Fourier Transform Infrared Spectroscopy in the Pulp and Paper Industry, 1st ed. R.A. Myers, 2000, pp. 8361-8388.

L. Bokobza & J. Zhang, “Raman spectroscopic characterization of multiwall carbon nanotubes and of composites”, Express Polymer Letters, n.o 6, pp. 601-608, 2012. DOI: https://10.3144/expresspolymlett.2012.63

G. Maurin, I. Stepanek, P. Bernier, J. Colomer, J. Nagy & F. Henn, “Segmented and opened multi-walled carbon nanotubes”, Carbon, n.o 39, pp. 1273-1278, 2000. DOI: https://www.researchgate.net/deref/http%3A%2F%2Fdx.doi.org%2F10.1016%2FS0008-6223(00)00250-5

“ASTM D790 - 17 Standard Test Methods for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials”, Astm.org, 2020. [Online]. Available: http://www.astm.org/Standards/D790.htm. [Accessed: 8-Aug-2020].

Z. Antar, J. Feller, H. Noël, P. Glouannec & P. Elleuch, “Thermoelectric behaviour of melt processed carbon nanotube/graphite/poly (lactic acid) conductive biopolymer nanocomposites (CPC)”, Materials Letters, n.o 67, pp. 210-214, 2012. DOI: https://10.1016/j.matlet.2011.09.060

M. Chiu & E. Prenner, “Differential scanning calorimetry: An invaluable tool for a detailed thermodynamic characterization of macromolecules and their interactions”, Journal of Pharmacy and Bioallied Sciences, n.o 3, pp. 39-59, 2011. DOI: https://10.4103/0975-7406.76463

X. Cao, A. Mohamed, S. Gordon, J. Willett & D. Sessa, “DSC study of biodegradable poly (lactic acid) and poly(hydroxy ester ether) blends”, Thermochimica Acta, n.o 406, pp. 115-127, 2003. DOI: https://10.1016/S0040-6031(03)00252-1

B. Stuart, Polymer Analysis, 1st ed. London: John Wiley and sons, 2002, p. 227.

“ASTM D638 - 14 Standard Test Method for Tensile Properties of Plastics”, Astm.org, 2020. [Online]. Available: http://www.astm.org/Standards/D638.htm. [Accessed: 8-Aug-2020].

[Online]. Available: http://scholar.lib.vt.edu/theses/available/etd-71498-94026/unrestricted/etd_Chapt_6.pdf. [Accessed: 08-Aug-2020].

“ASTM D7028 - 07(2015) Standard Test Method for Glass Transition Temperature (DMA Tg) of Polymer Matrix Composites by Dynamic Mechanical Analysis (DMA)”, Astm.org, 2020. [Online]. Available: http://www.astm.org/Standards/D7028.htm. [Accessed: 8-Aug-2020].

U. Kim, C. Furtado, X. Liu, G. Chen & P. Eklund, “Raman and IR Spectroscopy of Chemically Processed Single-Walled Carbon Nanotubes”, Journal of the American Chemical Society, 2005, n.o 127, pp. 15437-15445. DOI: https://doi.org/10.1021/ja052951o

Pubs.acs.org, 2020. [Online]. Available: http://pubs.acs.org/doi/pdf/10.1021/ba-1964-0043.ch001. [Accessed: 8-Aug-2020].

R. Rasal, R. Bradley, G. Bohannon & D. Hirt, “Effect of the Photoreaction Solvent on surface and Bulk Properties of Poly (lactic acid) and Poly(hydroxyalkanoate) Films”, Wiley InterScience, n.o 85, pp. 564-572, 2007. DOI: https://doi.org/10.1002/jbm.b.30980

“Earth & Planetary Sciences | The University of New Mexico”, Epsunm.edu, 2020. [Online]. Available: http://epswww.unm.edu/xrd/xrdbasics.pdf. [Accessed: 08-Aug-2020].

Industrial Materials Institute: http://www.speautomotive.com/SPEA_CD/SPEA2006/PDF/c/c2.pdf [Accesed: 23-Jun-2014].

C. Damian, S. Garea, E. Vasile, H. Iovu, “Covalent and non-covalent functionalized MWCNTs for improved thermo-mechanical properties of epoxy composites”, Composites Part B: Engineering., n.o 43, pp. 3507-3515, 2012. DOI: https://doi.org/10.1016/j.compositesb.2011.11.052

B. Scheibe, E. Borowiak-Palen & R. Kalenczuk, “Oxidation and reduction of multiwalled carbon nanotubes — preparation and characterization”, Materials Caracterization, n.o 61, pp. 185-191, 2010. DOI: https://doi.org/10.1016/j.matchar.2009.11.008

H. Yu, C. Lu, T. Xi1, L. Luo, J. Ning & C. Xiang, “Thermal decomposition of the carbon nanotube/SiO2”, Journal of Thermal Analysis and Calorimetry, n.o 82, pp. 97-101, 2005. DOI: https://doi.org/10.1007/s10973-005-0847-7

A. Mahajan, A. Kingon, A. Kukovecz, A. Konya & P. Vilarinho, “Studies on the thermal decomposition of multiwall carbon nanotubes under different atmospheres”, Materials Letters, n.o 90, pp. 165-168, 2013. DOI: https://doi.org/10.1016/j.matlet.2012.08.120

M. Dresselhaus, A. Jorio, M. Hofmann, G. Dresselhaus & R. Saito, “Perspectives on Carbon Nanotubes and Graphene Raman Spectroscopy”, Nanoletters, n.o 10, pp. 751-758, 2010. DOI: https://doi.org/10.1021/nl904286r

L. Bokobza & J. Zhang, “Raman spectroscopic characterization of multiwall carbon nanotubes and of composites”, eXPRESS Polymer Letters, n.o 6, pp. 601-608, 2012. DOI: https://10.3144/expresspolymlett.2012.63

C. Singh, M. Shaffer, K. Koziol, I. Kinlock & A. Windle, “Towards the production of large-scale aligned carbon nanotubes”, Chemical Physics Letters, n.o 372, pp. 860-865, 2003. DOI: https://doi.org/10.1016/S0009-2614(03)00531-1

P. Tan, S. Zhang, K. Yue, F. Huang, Z. Shi, X. Zhou & Z. Gu, “Comparative Raman Study of Carbon Nanotubes Prepared by D.C. Arc Discharge and Catalytic Methods”, Journal of Raman Spectroscopy, n.o 28, pp. 369-372, 1997. DOI: https://doi.org/10.1002/(SICI)1097-4555(199705)28:5%3C369::AID-JRS107%3E3.0.CO;2-X

N. Kouklin, M. Tzolov, D. Straus, A. Yin & J. Xu, “Infrared absorption properties of carbon nanotubes synthesized by chemical vapor”, Applied Physics Letters, n.o 85, pp. 4463-4465, 2004. DOI: https://doi.org.10.1063/1.1812837

A. Cao, C. Xu, J. Liang, D. Wu & B. Wei, “X-ray diffraction characterization on the alignment degree of carbon nanotubes”, Chemical Physics Letters, n.o 344, pp. 13-17, 2001. DOI: https://doi.org/10.1016/S0009-2614(01)00671-6

B. Dunlap, “Relating carbon tubules”, Physical Review B., n.o 49, pp. 5943-5650, 1994. DOI: https://doi.org/10.1103/PhysRevB.49.5643

I. Dubnikova, E. Kuvardina, V. Krasheninnikov, S. Lomakin, I. Tchmutin & S. Kuznetsov, “The Effect of Multiwalled Carbon Nanotube Dimensions on the Morphology, Mechanical, and Electrical Properties of Melt Mixed Polypropylene-Based Composites”, Journal of Applied Polymer Science, n.o 117, pp. 259-272, 2010. DOI: https://doi.org/10.1002/app.31979

J. Yoon, Y. Jeong, S. Lee & B. Min, “Influences of poly (lactic acid)-grafted carbon nanotube on thermal, mechanical, and electrical properties of poly (lactic acid)”, Polymers Advanced Technologies, n.o 20, pp. 631-638, 2008. DOI: https://doi.org/10.1002/pat.1312

D. Wu, L. Wu, W. Zhou, Y. Sun & M. Zhang, “Relations Between the Aspect Ratio of Carbon Nanotubes and the Formation of Percolation Networks in Biodegradable Polylactide/Carbon Nanotube Composites”, Journal of Polymer Science: Part B: Polymer Physics, n.o 48, pp. 479-489, 2010. DOI: https://doi.org/10.1002/polb.21909

D. Zhou, E. Anoshkina, L. Chow & G. Chai, “Synthesis of carbon nanotubes by electrochemical deposition at room temperature”, Carbon., n.o 44, pp. 1013-1016, 2006. DOI: https://doi.org/10.1016/j.carbon.2005.11.006

A. Osikoya, D. Wankasi, R. Vala, A. Afolabi & E. Dikio, Synthesis, characterization and adsorption studies of fluorine–doped carbon nanotubes”, Digest Journal of Nanomaterials and Biostructures, pp. 1187-1197, 2014. DOI: https://www.researchgate.net/profile/Adeniyi_Osikoya/publication/266201742_Synthesis_Characterization_and_adsorption_studies_of_fluorine-doped_carbon_nanotubes/links/54298f800cf27e39fa8e6263.pdf

S. Rahman, M. Islam & K. Shorowordí, “Electrodeposition and Characterization of Cooper Oxide Thin Films for Solar Cell Applications”, Procedia Engineering, n.o 105, pp. 679-685, 2015. DOI: https://doi.org/10.1016/j.proeng.2015.05.048

M. Gaillard, C. Kübel, C. Boulmer-Leborgne, D. Wang, N. Semmar, A. Petit & E. Millon, “High-resolution transmission electron microscope observations of multiwalled carbon nanotube microstructures grown by plasma enhanced chemical vapor deposition”, Journal of Vacuum Science & Technology B., n.o 31, pp. 031805, 2013. DOI: https://doi.org/10.1116/1.4804543

M. Terrones & H. Terrones, “The carbon nanocosmos: novel materials for the twenty-first century”, Philosophical Transactions of the Royal Society of London A., n.o 361, pp. 2789-2806, 2003. DOI: https://doi.org/10.1098/rsta.2003.1262

P. Ajayan, T. Ebbesen, T. Ichihashi, S. Iijima, K. Tanigaki & H. Hiura, “Opening carbon nanotubes with oxygen and implications for filling”, Letters of Nature, n.o 362, pp. 522-525, 1993. DOI: https://doi.org/10.1038/362522a0

B. Chieng, N. Ibrahim, V. Yunus & M. Hussein, “Plasticized Poly (lactic acid) with Low Molecular Weight Poly (ethylene glycol): Mechanical, Thermal, and Morphology Properties”, Journal of Applied Polymer Science, n.o 130, pp. 4576-4580. 2013. DOI: https://doi.org/10.1002/app.39742

ASTM D883. [Online]. Available: https://www.astm.org/Standards/D883.htm [Accesed: 25-april-16].

D. Battegazzore, S. Bocchini & A. Frache, “Crystallization kinetics of poly (lactic acid)-talc composites”, eXPRESS Polymer Letters., n.o 5, pp. 849-858, 2010. DOI: https://doi.org/10.3144/expresspolymlett.2011.84

K. Sungsanit, N. Kao & S. Bhattacharya, “Properties of Linear Poly (Lactic Acid)/Polyethylene Glycol Blends”, Polymer Engineering and Science, n.o 52, pp. 108-116, 2016. DOI: https://doi.org/10.1002/pen.22052

A. Mohapatra, S. Mohanty & S. Nayak, “Effect of PEG on PLA/PEG Blend and Its Nanocomposites: A Study of Thermo-Mechanical and Morphological Characterization”, Polymer Composites, n.o 35, pp. 283-293. 2014. DOI: https://doi.org/10.1002/pc.22660

X. Liu, M. Dever, N. Fair & R. Benson, “Thermal and Mechanical Properties of Poly (lactic Acid) and Poly(ethylene/butylene Succinate) Blends”, Journal of Environmental Polymer Degradation, n.o 5, pp. 225-235, 1997. DOI: https://doi.org/10.1007/BF02763666

http://www.ptonline.com/articles/tips-and-techniques-boosting-extrusión-productivitypart-iii-of-iii-trim-your-material-energy-costs [Accesed: 30-Jul-2017].

I. Pillin, N. Montrelay & Y. Grohens, “Thermo-mechanical characterization of plasticized PLA: Is the miscibility the only significant factor?”, Polymer, n.o 47, pp. 4676-4682, 2006. DOI: https://doi.org/10.1016/j.polymer.2006.04.013

V. Orozco, W. Brostow, W. Chonkaew & B. López, “Preparation and Characterization of Poly(Lactic Acid)-g-Maleic Anhydride + Starch Blends”, Macromolecular Symposia, n.o 277, pp. 69-80, 2009. https://doi.org/10.1002/masy.200950309

Oliveira, J., Zucolotto, V., Mattoso, L. & Medeiros, E. Multi-Walled Carbon Nanotubes and Poly (lactic acid) Nanocomposite Fibrous Membranes Prepared by Solution Blow Spinning. Journal of Nanoscience and Nanotechnology, n.o 11, pp. 1-9, 2011. DOI: https://doi.org.10.1166/jnn.2012.5730

C. Wu & H. Liao, “Study on the preparation and characterization of biodegradable polylactide/multi-walled carbon nanotubes nanocomposites”, Polymer, n.o 48, pp. 4449-4458, 2007. DOI: https://doi.org/10.1016/j.polymer.2007.06.004

S. Kim, K. Shin, S. Lee, K. Kim, & J. Youn. “Unique Crystallization Behavior of Multi-Walled Carbon Nanotube Filled Poly (lactic acid)”, Fibers and Polymers, n.o 11, pp. 1018-1023, 2010. DOI: https://doi.org/10.1007/s12221-010-1018-4

W. Lin, Y. Shih, C. Lin, C. Lee & Y. Yu, “The preparation of multi-walled carbon nanotube/poly (lactic acid) composites with excellent conductivity”, Journal of the Taiwan Institute of Chemical Engineers, n.o 44, pp. 489-496, 2013. DOI: https://doi.org/10.1016/j.jtice.2012.12.012

S. Bastida, J. Eguiazábal, M. Gaztelumendí & J. Nazábal, “On the Thickness Dependence of the Modulus of Elasticity of Polymers”, Polymer Testing, n.o 17, pp. 139-145, 1998. DOI: https://doi.org/10.1016/S0142-9418(97)00042-1

Rua.ua.es, 2020. [Online]. Available: https://rua.ua.es/dspace/bitstream/10045/3624/1/tema3RUA.pdf. [Accessed: 8-Aug-2020].

S. Yellampalli, Carbon nanotubes. Rijeka: InTech, 2011.

F. Li, S. Zhang, J. Liang & J. Wang, “Effect of polyethylene glycol on the crystallization and impact properties of polylactide-based blends”, Polymers Advanced Technologies, n.o 26, pp. 465-475, 2015. DOI: https://doi.org/10.1002/pat.3475

A. Kern & I. Madsen, Quantifying Amorphous Phases. Dordrecht: Springer, 2012, pp. 219-231.

T. Suzuki, K. Takahashi, H. Uehara & T. Yamanobe, “Application and analysis of a DSC-Raman spectroscopy for indium and poly (lactic acid)”, Journal of Thermal Analysis and Calorimetry, n.o 113, pp. 1543-1549, 2013. DOI: http://dx.doi.org/10.1007%2Fs10973-013-3098-z

J. Koenig & A. Angood, “Raman Spectra of Poly (ethy1ene Glycols) in Solution”, Journal of Polymer Science, n.o 8, pp. 1787-1796, 1970. DOI: https://doi.org/10.1002/pol.1970.160081013

J. A. Jansen, Failure Analysis and Prevention (ASM International), volume 11; Failure Analysis and Prevention: United States, 2002, pp. 437-459.

T. Ono, Fracture Analysis, a Basic Tool to Solve Breakage Issues, Corning, 2002, pp. 1-9.

A. Bhattacharyya, T. Sreekumara, T. Liu, S. Kumar, L. Ericson, R. Hauge & R. Smalley, “Crystallization and orientation studies in polypropylene/single wall carbon nanotube composite”, Polymer, n.o 44, pp. 2373-2377, 2003. DOI: https://doi.org/10.1016/S0032-3861(03)00073-9