Comparison of Effects of Plasma Surface Modifications of Bamboo and Hemp Fibers on Mechanical Properties of Fiber-Reinforced Epoxy Composites

Pornchai Rachtanapun; Choncharoen Sawangrat; Thidarat Kanthiya; Kannikar Kaewpai; Parichat Thipchai; Nuttapol Tanadchangsaeng; Patnarin Worajittiphon; Jonghwan Suhr; Pitiwat Wattanachai; Kittisak Jantanasakulwong

doi:10.3390/polym16233394

Comparison of Effects of Plasma Surface Modifications of Bamboo and Hemp Fibers on Mechanical Properties of Fiber-Reinforced Epoxy Composites

Polymers (Basel). 2024 Nov 30;16(23):3394. doi: 10.3390/polym16233394.

Authors

Affiliations

¹ Faculty of Agro-Industry, Chiang Mai University, Chiang Mai 50100, Thailand.
² Center of Excellence in Materials Science and Technology, Chiang Mai University, Chiang Mai 50200, Thailand.
³ Center of Excellence in Agro Bio-Circular-Green Industry, Faculty of Agro-Industry, Chiang Mai University, Chiang Mai 50100, Thailand.
⁴ Department of Industrial Engineering, Faculty of Engineering, Chiang Mai University, Chiang Mai 50200, Thailand.
⁵ Office of Research Administration, Chiang Mai University, Chiang Mai 50200, Thailand.
⁶ Science and Technology Park (STeP), Chiang Mai University, Chiang Mai 50100, Thailand.
⁷ Nanoscience and Nanotechnology, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.
⁸ College of Biomedical Engineering, Rangsit University, Pathumthani 12000, Thailand.
⁹ Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.
¹⁰ School of Mechanical Engineering, Sungkyunkwan University, Suwon-si 16419, Republic of Korea.
¹¹ Department of Civil Engineering, Faculty of Engineering, Chiang Mai University, Chiang Mai 50200, Thailand.

Abstract

In this study, we investigated the behaviors of epoxy composites reinforced with bamboo (BF) and hemp (HF) fibers. Both fibers were treated using dielectric barrier discharge (DBD) plasma for various durations (2.5 to 20 min). Epoxy resin (ER) was mixed with BF or HF with and without plasma treatment. The Fourier-transform infrared spectra of the plasma-treated fibers showed an enhanced peak intensity of carboxyl groups. ER/BF treated for 20 min exhibited a high tensile strength (up to 56.5 MPa), while ER/HF treated for 20 min exhibited a more significant increase in elongation at break (6.4%). Flexural tests indicated that the plasma treatment significantly improved the flexural strength of the hemp composites (up to 62.2 MPa) compared to the bamboo composites. The plasma treatment increased the fiber surface roughness and interfacial bonding in both composites. The thermal stability and wettability were improved by the DBD plasma treatment. The DBD plasma treatment enhanced the interfacial adhesion between fibers and ER matrix, which improved the mechanical, thermal, and wettability properties of the composites.

Keywords: bamboo; epoxy composites; hemp; plasma; surface modification.

Grants and funding

This research has received funding support from the NSRF via the Program Management Unit for Human Resources and Institutional Development, Research, and Innovation (grant number B16F640206). This research work was partially supported by Chiang Mai University. The present study was partially supported by the Thailand Research Fund (TRF) Research Team Promotion Grant, RTA, Senior Research Scholar (N42A671052). This research and innovation activity was funded by the National Research Council of Thailand (NRCT) under the “Hub of Talents in Bioplastics for Use in Medical Applications” (Grant No. N34E670071).