Investigation of the effects of water uptake on the mechanical properties of wood dust particle filled Prosopis Juliflora reinforced phenol formaldehyde hybrid polymer composites

The water uptake behavior of Wood Dust (WD)/Prosopis Juliflora Fiber (PJF)/Phenol-Formaldehyde (PF) hybrid composites which are immersed in distilled and seawater environments was evaluated. Three different composite samples were fabricated by reinforcing WD and PJF with PF resin. The fabricated specimens were immersed in sea and distilled water to note down the moisture content absorption of the specimens for different time intervals from 0 to 240 h. The dry and wet specimens underwent mechanical properties testing as per ASTM standards and the findings for wet and dry specimens have been compared and analyzed. It is observed that the specimens which are immersed in sea (salt) water absorb more moisture content than the specimen immersed in distilled water and the PJF-rich (30 wt% of PJF & 10 wt % of WD) specimen absorbs more water than the other specimens. The water uptake behavior of the WD/PJF/PF hybrid composite follows a non-Fickian behavior. The mechanical performance (tensile, flexural, and impact) of the 10 wt % of WD 30 wt % of PJF specimen was better than that of other specimens at dry (before immersion) conditions and lost strength when immersed in sea and distilled water. SEM analysis was also done on the broken surface of the tested specimens which were exposed to the water environment.