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Composites of high-temperature thermomechanical pulps and polylactic acid

Research output: Contribution to journalArticleScientificpeer-review

Details

Original languageEnglish
Pages (from-to)1125-1140
Number of pages16
JournalBioResources
Volume11
Issue number1
DOIs
Publication statusPublished - 2016
Publication typeA1 Journal article-refereed

Abstract

High-temperature thermomechanical pulps (HT-TMP, defibrated at 150 to 170 °C) were compared to a reference TMP (defibrated at 130 °C) as a reinforcement for polylactic acid (PLA). Composites were prepared by melt compounding, followed by injection molding, gradually increasing the used fiber content from 0 to 20 wt.%. The injection-molded specimens were characterized by tensile and impact strength tests, scanning electron microscopy, water absorption tests, and differential scanning calorimetry. The TMP fiber damage was also characterized before and after melt compounding by optical analysis. At 20% fiber content, the Young's modulus increased significantly, while the tensile strength remained unchanged and the impact strength decreased slightly. All fibers suffered damage during melt compounding, but the tensile strength remained about the same as in pure PLA. All types of TMP were able to increase the PLA rate of crystallization. The HT-TMP fibers were dispersed more evenly in PLA than the 130 °C TMP. The 170 °C TMP produced composites of lower water absorption than the other two TMP types, probably because of its lower hemicellulose content and its higher surface coverage by lignin.

Keywords

  • High-temperature thermomechanical pulp, Hydrophobic fibers, Mechanical properties, Polylactic acid, Thermal properties, Wood fiber composites

Publication forum classification

Field of science, Statistics Finland