Studies on the Properties of Sisal Fibre/Phenol Formaldehyde Resin In-situ Composites

In this paper sisal fibre (SF) was pretreated by alkali, KH-550, and steam explosion. Then sisal fibre/phenol formaldehyde (SF/PF) composites were prepared through compression molding. The effects of the sisal fibre addition mode and sisal/glass (SF/GF) hybrid phenol formaldehyde composites with glass/sisal weight ratio on mechanical properties, thermal properties, water absorption properties and electrically insulating properties were studied. Meanwhile, the effects of sisal treatments were also examined. Results indicate that polymerization-filling is a novel synthesizing method and KH-550 treatment is an ideal method for the modification of SF. The SF/PF composites made by the polymerization-filling method increased by 17.61%, 7.16% and 12.25% in impact strength, bending strength and bending modulus respectively compared with using the conventional physical blending method. SF/GF/PF composites showed higher mechanical properties when SF/GF was 1/1, and thermal properties improved with the addition of GF; sisal fibre and glass fibre exhibited positive hybrid effect in water absorption properties while negative hybrid effect in insulating properties. A study of fibre-matrix interaction and fracture behavior of the fractured surfaces of the composites was also made by scanning electron micrographs.