Abstract
Plasma polymerisation was used to treat glass fibres to improve their interfacial bond to polypropylene. After the glass fibres were treated with a coupling agent, four different monomers were polymerised onto the fibre surfaces with a plasma. The plasma polymers changed the surface morphology and surface free energy of the fibres. The experimental results indicate that a particle-like surface induces a transcrystalline layer to form on the fibre surface and improves the polypropylene/glass fibre interfacial shear strengthrelative to glass fibres treated with coupling agent only. Glass fibres treated with coupling agent and then with acrylonitrile and styrene showed an increase in the interfacial bond strength between polypropylene and glass fibres of 65% and 81% respectively. Those glass fibre surfaces treated with particle-like organosilicon, plasma polymerised tetramethylsilane (PP/TMS) and hexamethyldisiloxane (PP/HMDSO), induced a transcrystalline layer to form and there was an increase in the interfacial shear strength of 196% and 160% respectively, i.e. it was 70% and 49% higher than that for samples treated with coupling agent only.