Project Abstract

Fibre-reinforced Cellulose Acetate Composites

Janny Ke and Karen Yu
Sir Winston Churchill Secondary School, Grade 11

Plastics made almost completely of garbage: is it possible? Our natural fibre-reinforced cellulose acetate composites can potentially replace current non-biodegradable and harmful plastics and minimize the amount of garbage in landfill by using agricultural and household wastes. We wanted to determine how the type of reinforcement fibre --hemp, flax, pomelo skins, onion peels and hair -- reinforced with anisotropic short fibre method at 5%, 25%, or 45% by composite mass, affected the tensile, flexural strength, and conductivity of the composite. Our samples were made by dissolving cellulose acetate fabrics in acetone and mixing in the fibres.

We found that by comparing samples of the same total mass (different mass content for the matrix), the reinforcement fibres actually reduced the overall tensile strength as well as maximum bending stress of the cellulose acetate. However, the samples that contained the reinforcement material was less brittle and required multiple fractures to break completely, perhaps due to the fibres bridging stress across the broken part of cellulose acetate matrix. The flexural tests showed that composites seem to be more resilient and be able to withstand constant distortion. Not the composites nor the cellulose acetate were electricity conductors, showing their potential in electronic equipments.

The pomelo skin and onion peel weakened the matrix strength dramatically and binds poorly with it. Among the composites, the hair reinforcement performed the best, followed by flax and hemp. Our results suggest that the flax, hemp, and hair composites may be able to equal if not excel the tensile and properties had the matrix mass between different samples be the same.