Morphology and Properties of Polypropylene Blends Containing Phenolic Resin Produced from the Liquefaction of Empty Fruit Bunch Fibres

Phenol formaldehyde (PF) resin prepared from phenol-liquefied empty fruit bunch (EFB) fibres was blended with polypropylene (PP) using a co-rotating twin-screw extruder. The effects of the PF content (10, 20, 30 and 40 wt.%) blended with PP on the properties of the PP/PF board were investigated. SEM images depicted the formation of spherical protuberances and voids in the PP/PF board with the increasing PF content. The size of the protuberances was also increased with the PF content. The formation of void could be due to the release of water, ammonia and formaldehyde during the blending and hot-press processes. The density, moisture content and maximum water absorption of the PP/PF board increased with the increase of PF content. The TG curves of the PP/PF boards revealed that the PF and PP in the PP/PF board decomposed at different temperature ranges, i.e., 200–420 and 425–480 °C, respectively. The addition of PF to PP reduced the activation energy of the first stage thermal decomposition of the PP/PF boards. The addition of 10 wt.% PF was the optimum content to produce PP/PF board with optimum mechanical properties.