Preparation and properties of thermally stable lignin-based copolymer/PP blends by melt process

Goeun Kim, In Kyung Park, Sung Hoon Kim, Youngjun Kim, Hee Won Seo, Ju Ho Yun, Soo Hyun Kim, Dong Kwan Kim, Jae Do Nam

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


Lignin-based polycaprolactone (LigPCL) copolymer was synthesized by both the ring opening reaction of ϵ-caprolactone with the hydroxyl groups in the lignin and the concomitant polymerization of ϵ-caprolactone. FTIR spectra showed C=O (1755 cm-1) and C-O (1202 cm-1) peaks confirming that the esterification reaction took place successfully between lignin and ϵ:-caprolactone. T2, at which the weight loss of 2% occurs, of pristine lignin and LigPCL were measured as 63 and 211 °C, respectively, and so the synthesized LigPCL had superior thermal stability to the lignin. PP/Lig-PCL blends were prepared at various contents of LigPCL up to 30 wt% by a melt extrusion process. In proportion to the content of the LigPCL, tensile strengths, flexural strengths, and tensile modulus of PP/LigPCL blends greatly decreased, but elongations at break of those greatly increased. To improve the compatibility between PP and LigPCL, maleic anhydride-grafted polypropylene (PP-g-MA) was added. SEM images for the fracture surfaces of the blends showed that the PP-g-MA was effective in reducing the domain size of dispersed phase. Thus, T2, tensile strength, tensile modulus, and elongation at break of a 70/30 blend of PP/LigPCL were enhanced by 6 °C, 17%, 31%, and 79%, respectively, by the addition of PP-g-MA. This work clearly demonstrates that thermoplastic LigPCL could be desirably synthesized and applied for value added and eco-friendly products through common melt processes used for polymer blend or composites manufacturing.

Original languageEnglish
Pages (from-to)313-320
Number of pages8
JournalPolymer (Korea)
Issue number2
Publication statusPublished - 2016 Mar

Bibliographical note

Publisher Copyright:
© 2016 The Polymer Society of Korea. All rights reserved.


  • Bioplastics
  • Compatiblizer
  • Lignin polymer
  • Mechanical properties
  • Thermal stability

ASJC Scopus subject areas

  • General Chemical Engineering
  • Polymers and Plastics
  • Materials Chemistry


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