Natural fiber

Fibre-reinforced plastic

Composite number

Engineering

Materials science

Cellulose

Fiber-reinforced composite

Cellulose fiber

Chemical engineering

Organic chemistry

SISAL

Composite material

Fiber

Synthetic fiber

Chemistry

Kenaf

Coir

Lignin

Composite Interfaces

The aim of this paper was to review the recent advances in treatment strategies for natural fibers before their utilization in a reinforced composite in the last 5 years. More focus was placed on experimental methodology and how the treatment affects the final composite properties. The review was conducted to determine the important treatment steps, identify the empirical methodology in terms of process parameters, draw some fundamental conclusions on the topic, identify knowledge gaps, and discuss future perspective in the area of research. About 70% of research studies on fiber treatment for plastic composite development used NaOH as the reagent. For most processes, room temperature (25°C) was utilized. However, some studies have raised the temperature for their process to weaken the interactions between the cellulose strands in the lignin and help the reagent gain quick access into the fibers. The concentration of the treatment chemical usually did not exceed 20 wt% but lies between 1 and 10 wt% most of the time. A long process time was only used when concentration is low. Natural fibers commonly treated and used to reinforce composites include kenaf, banana, jute, sisal, hemp, coir, pineapple leaf, luffa, flax amongst others. Treated fibers showed enhanced interfacial bonding between the fibers and great improvement in their mechanical properties. In the future, it is expected that more interest will be paid to develop novel techniques of fiber treatment that will improve the properties beyond what we already have today.

An empirical review of the recent advances in treatment of natural fibers for reinforced plastic composites