Polypropylene and Aliphatic Polyester Flax Fibre Composites
Composite materials have been prepared from hydrophobic and hydrophilic polypropylene with flax fibres, where the flax fibres have been used with and without silane surface treatment. Other comparable composites have been prepared from poly(lactic acid) and poly(ethylene succinate), recently developed biodegradable polymers with promising mechanical properties. The polar polymers were found to provide better wetting of the surface of the flax, regardless of the surface treatment. Differential scanning calorimetry (DSC) was used to study the crystallisation and melting of the composites compared with the pure polymers. The surface wetting of the fibres and morphology of the composites was studied by scanning electron microscopy (SEM) and optical microscopy. Mechanical properties were studied using dynamic mechanical analysis (DMA). It was found that the relatively low density flax fibres provide efficient reinforcement compared with that expected from analogous glass fibre composites. The influence of the transcrystalline interphase on the dynamic storage modulus was found to be important.