Background: Natural fibres are getting substantial attention as reinforcement
in polymer composites. However, they are commonly recognised to have poor
compatibility with polymers. Hence, it is important to enhance the interfacial bonding
of natural fibres. Recent patents have highlighted several alternatives to improve the
Objective: In this study, the interfacial shear strength of untreated and 10wt% sodium
hydroxide (NaOH) treated bamboo fibre reinforced polyester composites was investigated.
Method: The bamboo fibre length was fixed at 7mm in both cases. The interfacial
shear strength was measured through single fibre pull-out test (SFPT) and subsequently analysed using
Weibull distribution plot. Results were also compared with the data from literature. Finally, scanning
electron micrographs (SEM) were captured to analyse the debonded surfaces of both matrix and fibre.
Results: Results showed that the interfacial shear strength of the treated fibre was improved by almost
three fold higher than the untreated fibre. In addition, Weibull analysis revealed that the Weibull moduli
were similar for both untreated and treated fibres. This suggested that surface impurities were formed on
the treated fibre due to the damage induced by sodium hydroxide. Furthermore, scanning electron micrographs
showed that alkalisation has modified the fibre surface morphology and improved the overall surface
quality for better interfacial bonding.
Conclusion: In conclusion, alkali treatment is a potential method to improve the interfacial characteristics
of bamboo fibre in unsaturated polyester. Recent patent suggested that coating with bacterial cellulose is a
green technique for better interfacial bonding behaviour.