Cellulose kraft pulp reinforced polylactic acid (PLA) composites: effect of fibre moisture content

Sanna Virtanen; Lisa Wikström; Kirsi Immonen; Upi Anttila; Elias Retulainen; Sanna Virtanen; Lisa Wikström; Kirsi Immonen; Upi Anttila; Elias Retulainen

doi:10.3934/matersci.2016.3.756

AIMS Materials Science

2016, Volume 3, Issue 3: 756-769. doi: 10.3934/matersci.2016.3.756

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Research article Topical Sections

Cellulose kraft pulp reinforced polylactic acid (PLA) composites: effect of fibre moisture content

1.
Department of Fibres and Biobased Materials, VTT Technical Research Centre of Finland Ltd, Sinitaival 6, P.O. Box 1300, Tampere FI-33101, Finland
2.
Department of Fibres and Biobased Materials, VTT Technical Research Centre of Finland Ltd, Koivurannantie 1, P.O. Box 1603, FI-40101 Jyväskylä, Finland

Received: 31 May 2016 Accepted: 28 June 2016 Published: 30 June 2016

PLA offers a competitive and CO₂ neutral matrix to commonly used polyolefin polymer based composites. Moreover, the use of PLA reduces dependency on oil when producing composite materials. However, PLA has a tendency of hydrolytic degradation under melt processing conditions in the presence of moisture, which remains a challenge when processing PLA reinforced natural fibre composites. Natural fibres such as cellulose fibres are hygroscopic with 6–10 wt% moisture content at 50–70% relative humidity conditions. These fibres are sensitive to melt processing conditions and fibre breakage (cutting) also occur during processing. The degradation of PLA, moisture absorption of natural fibres together with fibre cutting and uneven dispersion of fibres in polymer matrix, deteriorates the overall properties of the composite.
In the given research paper, bleached softwood kraft pulp (BSKP) reinforced PLA compounds were successfully melt processed using BSKP with relatively high moisture contents. The effect of moist BSKP on the molecular weight of PLA, fibre length and the mechanical properties of the composites were investigated. By using moist never-dried kraft pulp fibres for feeding, the fibre cutting was decreased during the melt compounding. Even though PLA degradation occurred during the melt processing, the final damage to the PLA was moderate and thus did not deteriorate the mechanical properties of the composites. However, comprehensive moisture removal is required during the compounding in order to achieve optimal overall performance of the PLA/BSKP composites. The economic benefit gained from using moist BSKP is that the expensive and time consuming drying process steps of the kraft pulp fibres prior to processing can be minimized.
- poly(lactic acid),
- bleached softwood kraft pulp,
- degradation,
- mechanical properties,
- compounding,
- injection moulding
Citation: Sanna Virtanen, Lisa Wikström, Kirsi Immonen, Upi Anttila, Elias Retulainen. Cellulose kraft pulp reinforced polylactic acid (PLA) composites: effect of fibre moisture content[J]. AIMS Materials Science, 2016, 3(3): 756-769. doi: 10.3934/matersci.2016.3.756

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Abstract

PLA offers a competitive and CO₂ neutral matrix to commonly used polyolefin polymer based composites. Moreover, the use of PLA reduces dependency on oil when producing composite materials. However, PLA has a tendency of hydrolytic degradation under melt processing conditions in the presence of moisture, which remains a challenge when processing PLA reinforced natural fibre composites. Natural fibres such as cellulose fibres are hygroscopic with 6–10 wt% moisture content at 50–70% relative humidity conditions. These fibres are sensitive to melt processing conditions and fibre breakage (cutting) also occur during processing. The degradation of PLA, moisture absorption of natural fibres together with fibre cutting and uneven dispersion of fibres in polymer matrix, deteriorates the overall properties of the composite.
In the given research paper, bleached softwood kraft pulp (BSKP) reinforced PLA compounds were successfully melt processed using BSKP with relatively high moisture contents. The effect of moist BSKP on the molecular weight of PLA, fibre length and the mechanical properties of the composites were investigated. By using moist never-dried kraft pulp fibres for feeding, the fibre cutting was decreased during the melt compounding. Even though PLA degradation occurred during the melt processing, the final damage to the PLA was moderate and thus did not deteriorate the mechanical properties of the composites. However, comprehensive moisture removal is required during the compounding in order to achieve optimal overall performance of the PLA/BSKP composites. The economic benefit gained from using moist BSKP is that the expensive and time consuming drying process steps of the kraft pulp fibres prior to processing can be minimized.

References

[1]	ABC’s of FRP Materials, Automotive Composites Alliance, American Composites Manufacturers Association (2016) Available from: http://www.autocomposites.org/ composites101/abc.cfm.
[2]	Bledzki AK, Jaszkiewicz A (2010) Mechanical performance of biocomposites based on PLA and PHBV reinforced with natural fibres – A comparative study to PP. Compos Sci Technol 70: 1687–1696. doi: 10.1016/j.compscitech.2010.06.005
[3]	Hossain KMZ, Parsons AJ, Rudd CD (2014) Mechanical, crystallisation and moisture absorption properties of melt drawn polylactic acid fibres. Eur Polym J 53: 270–281. doi: 10.1016/j.eurpolymj.2014.02.001
[4]	Document on crystallization and drying of PLA, NatureWorks LLC, 2016. Available from: www.natureworksllc.com.
[5]	Oever MJAVD, Beck B, Müssig J (2010) Agrofibre reinforced poly(lactic acid) composites: Effect of moisture on degradation and mechanical properties. Compos Part A–Appl S 41: 1628–1635. doi: 10.1016/j.compositesa.2010.07.011
[6]	Penjumras P, Rahman RA, Talib RA (2015) Mechanical properties and water absorption behaviour of durian rind cellulose reinforced Poly(lactic acid) biocomposites. Int J Sci Engg Tech 5:343–349.
[7]	Ganster J, Fink HP, Pinnow M (2006) High-tenacity man-made cellulose fibre reinforced thermoplastics – injection moulding compounds with polypropylene and alternative matrices. Compos Part A–Appl S 37: 1796–1804.
[8]	Jonoobi M, Harun J, Mathew AP (2010) Mechanical properties of cellulose nanofiber (CNF) reinforced polylactic acid (PLA) prepared by twin screw extrusion. Compos Sci Technol 70: 1742–1747. doi: 10.1016/j.compscitech.2010.07.005
[9]	Sippola M, Immonen K, Miettinen A (2015) Predicting stiffness and strength of birch pulp- Polylactic acid composites. J Compos Mater.
[10]	Huda MS, Drzal LT, Misra M (2006) Wood–fiber-reinforced poly(lactic acid) composites: evaluation of the physicomechanical and morphological properties. J Appl Polym Sci 102: 4856–4869. doi: 10.1002/app.24829
[11]	Oksman K, Skrifvars M, Selin JF (2003) Natural fibres as reinforcement in polylactic acid (PLA) composites. Compos Sci Technol 63: 1317–1324. doi: 10.1016/S0266-3538(03)00103-9
[12]	Anuar H, Zuraida A, Fuad F (2010) Biodegradable PLA-Kenaf Fibre Biocomposite for Cleaner Environment. In: Malaysian Science and Technology Congress (MSTC 2010), Crystal Crown Hotel, Petaling Jaya, Malaysia.
[13]	Laxmeshwar SS, Viveka S, Madhu Kumar DJ, et al. (2012) Preparation and properties of composite films from modified cellulose fibre-reinforced with PLA. Der Pharma Chem 4: 159–168.
[14]	Fujiura T, Sakamoto K, Tanaka T (2015) A study on preparation and mechanical properties of long jute fiber reinforced polylactic acid by the injection molding process. In: Syngellakis S, Composites: Advances in Manufacture and Characterisation, WIT Transactions on State of the Art in Science and Engineering, WIT Press, 109–118.
[15]	Fu SY, Mai YW, Ching ECY (2002) Correction of the measurement of fiber length of short fiber reinforced thermoplastics. Compos Part A Appl S 33: 1549–1555. doi: 10.1016/S1359-835X(02)00114-8
[16]	Ariño R, Boldizar A (2013) Barrier screw compounding and mechanical properties of EEA copolymer and cellulose fiber composite. Int Polym Process XXVIII 4: 421–428.
[17]	Baillif ML, Oksman K (2009) The effect of processing on fiber dispersion, fiber length, and thermal degradation of bleached sulphite cellulose fiber polypropylene composites. J Thermoplast Compos Mater 22: 115–133. doi: 10.1177/0892705708091608
[18]	Peltola H, Pääkkönen E, Jetsu P (2014) Wood based PLA and PP composites: Effect of fibre type and matrix polymer on fibre morphology, dispersion and composite properties. Compos Part A–Appl S 61: 13–22. doi: 10.1016/j.compositesa.2014.02.002
[19]	Peltola H, Laatikainen E, Jetsu P (2011) Effects of physical treatment of wood fibres on fibre morphology and biocomposite properties. Plast Rubber Compos 40: 86–92. doi: 10.1179/174328911X12988622801016
[20]	Sykacek E, Hrabalova M, Frech H (2009) Extrusion of five biopolymers reinforced with increasing wood flour concentration on a production machine, injection moulding and mechanical performance. Compos Part A–Appl S 40: 1272–1282. doi: 10.1016/j.compositesa.2009.05.023
[21]	Peltola H, Madsen B, Joffe R (2011) Experimental study of fiber length and orientation in injection molded natural fiber/starch acetate composites. Adv Mater Sci Eng 891940: 1–7.
[22]	Barkoula NM, Garkhail SK, Peijs T (2010) Effect of compounding and injection molding on the mechanical properties of flax fiber polypropylene composites. J Reinf Plast Compos 29: 1366–1385. doi: 10.1177/0731684409104465
[23]	Karmarkar A, Chauhan SS, Modak JM (2007) Mechanical properties of wood–fiber reinforced polypropylene composites: effect of a novel compatibilizer with isocyanate functional group. Compos Part A–Appl S 38: 227–233. doi: 10.1016/j.compositesa.2006.05.005
[24]	Amash A, Zugenmaier P (2000) Morphology and properties of isotropic and oriented samples of cellulose fibre–polypropylene composites. Polymer 41: 1589–1596. doi: 10.1016/S0032-3861(99)00273-6
[25]	Stamboulis A, Baillie CA (2000) Environmental durability of flax fibres and their composites based on polypropylene matrix. Appl Compos Mater 7: 273–294. doi: 10.1023/A:1026581922221
[26]	Doan T, Gao S, Mäder E (2006) Jute/polypropylene composites I. Effect of matrix modification. Compos Sci Technol 66: 952–963.
[27]	Fernandes Diniz JMB, Gil MH, Castro JAAM (2004) Hornification – its origin and interpretation in wood pulps. Wood Sci Technol 37: 489–494. doi: 10.1007/s00226-003-0216-2
[28]	Smook GA (1990) Hornification (keyword), In: Wilde A, Handbook of pulp and paper terminology, Vancouver: Angus Wilde 135.
[29]	Minor JL (1994) Hornification – its origin and meaning. Progr Pap Recycling 3: 93–95.
[30]	Retulainen E, Martikainen P, Timofeev O (2015) Drying tension and shrinkage in paper and board: Part 1 Single ply sheets of chemical and mechanical furnishes. Appita J 68: 51–54.
[31]	Weise U (1997) Characterization and mechanisms of changes in wood pulp fibres caused by water removal. Acta Polytechnica Scandinavica, Chemical Technology Series No. 249, Laboratory of Paper Technology, Department of Forest Products Technology, Helsinki University of Technology, 1–141.
[32]	Herrera N, Mathew AP, Oksman K (2015) Plasticized polylactic acid/cellulose nanocomposites prepared using melt-extrusion and liquid feeding: mechanical, thermal and optical properties. Compos Sci Technol 106: 149–155.
[33]	Nikkilä M, Ture T (2014) Method and apparatus for the manufacturing of composite material. WO 2014/181036 A1.
[34]	Eshuis PG, van der Weele K, van der Meer D (2005) Granular Leidenfrost effect: Experiment and theory of floating particle clusters. Phys Rev Lett 95: 258001. doi: 10.1103/PhysRevLett.95.258001
[35]	Eshuis K, van der Weele D, van der Meer D, Lohse D (2005) The granular Leidenfrost effect, In: Garcia-Rojo R, Herrmann HJ, McNamara S, Powders and Grains, Leiden: Balkema Publication, 1155–1158.
[36]	Eshuis P, van der Weele K, van der Meer D (2007) Phase diagram of vertically shaken granular matter. Phys Fluids 19: 123301. doi: 10.1063/1.2815745
[37]	Eshuis P, van der Meer D, Alam M (2010) Onset of convection in strongly shaken granular matter. Phys Rev Lett 104: 038001. doi: 10.1103/PhysRevLett.104.038001
[38]	Masutani K, Kimura Y (2014) Chapter 1: PLA Synthesis. From the Monomer to the Polymer, In: Jiménez A, Peltzer M, Ruseckaite R, Poly(lactic acid) Science and Technology: Processing, Properties, Additives and Applications, RSC Polymer Chemistry Series No. 12, 1–36.
[39]	Garlotta D (2001) A Literature Review of Poly(Lactic Acid). J Polym Environ 9: 63–84. doi: 10.1023/A:1020200822435
[40]	Kuhasalo A, Niskanen J, Paltakari J (2000) Introduction to paper drying and principles and structure of a dryer section, In: Karlsson M, Papermaking Part 2: Drying, Papermaking Science and Technology Series 9, Fapet Oy, Helsinki, 16−53.
[41]	Reduced energy consumption in plastics engineering (2005) European benchmarking survey of energy. Available from: http://ec.europa.eu/energy/intelligent/projects/sites/iee-projects/files/ projects/documents/recipe_benchmarking_report.pdf.

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