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

Sanna Virtanen (Corresponding Author), Lisa Wikström, Kirsi Immonen, Upi Anttila, Elias Retulainen

Research output: Contribution to journalArticleScientificpeer-review

8 Citations (Scopus)

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.
Original languageEnglish
Pages (from-to)756-769
JournalAIMS Materials Science
Volume3
Issue number3
DOIs
Publication statusPublished - 2016
MoE publication typeA1 Journal article-refereed

Fingerprint

Kraft pulp
Cellulose
Moisture
Acids
Fibers
Softwoods
Composite materials
Natural fibers
Processing
Degradation
poly(lactic acid)
Mechanical properties
Polyolefins
Polymer matrix
Atmospheric humidity
Drying
Polymers
Oils
Molecular weight
Economics

Keywords

  • poly(lactic acid)
  • bleached softwood kraft pulp
  • degradation
  • mechanical properties
  • compounding
  • injection moulding

Cite this

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title = "Cellulose kraft pulp reinforced polylactic acid (PLA) composites: effect of fibre moisture content",
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.",
keywords = "poly(lactic acid), bleached softwood kraft pulp, degradation, mechanical properties, compounding, injection moulding",
author = "Sanna Virtanen and Lisa Wikstr{\"o}m and Kirsi Immonen and Upi Anttila and Elias Retulainen",
note = "SDA: SHP: Bioeconomy",
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doi = "10.3934/matersci.2016.3.756",
language = "English",
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pages = "756--769",
journal = "AIMS Materials Science",
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Cellulose kraft pulp reinforced polylactic acid (PLA) composites: effect of fibre moisture content. / Virtanen, Sanna (Corresponding Author); Wikström, Lisa; Immonen, Kirsi; Anttila, Upi; Retulainen, Elias.

In: AIMS Materials Science, Vol. 3, No. 3, 2016, p. 756-769.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Cellulose kraft pulp reinforced polylactic acid (PLA) composites: effect of fibre moisture content

AU - Virtanen, Sanna

AU - Wikström, Lisa

AU - Immonen, Kirsi

AU - Anttila, Upi

AU - Retulainen, Elias

N1 - SDA: SHP: Bioeconomy

PY - 2016

Y1 - 2016

N2 - 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.

AB - 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.

KW - poly(lactic acid)

KW - bleached softwood kraft pulp

KW - degradation

KW - mechanical properties

KW - compounding

KW - injection moulding

U2 - 10.3934/matersci.2016.3.756

DO - 10.3934/matersci.2016.3.756

M3 - Article

VL - 3

SP - 756

EP - 769

JO - AIMS Materials Science

JF - AIMS Materials Science

SN - 2372-0468

IS - 3

ER -