Effect of extraction methods on the molecular structure and thermal stability of kenaf (Hibiscus cannabinus core) biomass as an alternative bio-filler for rubber composites

Nor Anizah Mohamad Aini; Nadras Othman; M Hazwan Hussin; Kannika Sahakaro; Nabil Hayeemasae

doi:10.1016/j.ijbiomac.2019.10.280

Effect of extraction methods on the molecular structure and thermal stability of kenaf (Hibiscus cannabinus core) biomass as an alternative bio-filler for rubber composites

Int J Biol Macromol. 2020 Jul 1:154:1255-1264. doi: 10.1016/j.ijbiomac.2019.10.280. Epub 2019 Nov 22.

Authors

Nor Anizah Mohamad Aini¹, Nadras Othman², M Hazwan Hussin³, Kannika Sahakaro⁴, Nabil Hayeemasae⁴

Affiliations

¹ School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, Engineering Campus, 14300 Nibong Tebal, Pulau Pinang, Malaysia.
² School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, Engineering Campus, 14300 Nibong Tebal, Pulau Pinang, Malaysia. Electronic address: srnadras@usm.my.
³ School of Chemical Science Universiti Sains Malaysia, 11800, Minden, Pulau Pinang, Malaysia.
⁴ Department of Rubber Technology and Polymer Science, Faculty of Science and Technology, Prince of Songkla University, Pattani Campus, Pattani 94000, Thailand.

PMID: 31765744
DOI: 10.1016/j.ijbiomac.2019.10.280

Abstract

Lignin from kenaf (Hibiscus cannabinus) core was investigated as an alternative filler for rubber. Three types of extraction methods were used to isolate lignin from kenaf, namely kraft, soda and organosolv process. The particle size, surface area, functionalities changes, molecular weight and thermal properties of the lignin were characterized. The results showed that Kraft lignin (KL) has the smallest particle size (40.41 μm) compared to soda lignin (SL) (63.85 μm) and organosolv lignin (OL) (66.85 μm). This is in good agreement with the BET surface area of 9.52 m²/g, 1.25 m²/g and 2.40 m²/g respectively. However, the smaller surface area of SL compared to OL is due to the smaller pore size and pore volume of SL. KL also showed high hydroxyl content with corresponding high thermal stability as confirmed by NMR and TGA. The thermal stability of the lignin correlates well with the molecular weight (MW). From the overall characteristics, it can be concluded that KL, SL and OL can be used as an alternative filler in rubber compounds to substitute common fillers like silica and carbon.

Keywords: Filler; Kenaf; Lignin; Rubber composites; Thermal behaviour.

MeSH terms

Biomass*
Chemical Fractionation / methods*
Hibiscus / chemistry*
Lignin / chemistry
Molecular Weight
Particle Size
Rubber / chemistry*
Rubber / isolation & purification*
Silicon Dioxide / chemistry
Surface Properties
Temperature*

Substances

Silicon Dioxide
Lignin
Rubber