Department: Chemical Engineering
Odera, S. R.
Onukwuli, D. O.
Raffia palm fibre polymer-modified cement mortar composites for roofing sheet application was developed.The cement mortar composite was produced following standard method by varying the raffia palm fiber (RPF) and raffia palm fiber ash particles (RPFAp) from 0.0 to 25% volume, and 5.0% volume polyester and polyvinylalcohol (PVA) were used to modify the cement. The density, water absorption, X-ray diffraction analysis, atomic force microscopy, scanning electron microscopy, compressive strength, tensile and flexural strength, DTA/TGA were evaluated. Factorial design (FD) was used to analyze the fiber treatment, water absorption and compressive strength of the cement mortar. The results obtained showed that the maximum strength of the pretreated fiber (89.844N/mm2) was achieved at a NaOH concentration of 0.25M for 1hr. This study showed that a concentration of 80% ethanol in H2O with silane on the mercerized fibers produced the best results; with water absorbance of plant fiber drastically reduced to 3% which is an improvement of 91% when compared to that of the raw fiber (34.83%). The density of the composites decreased as the volume fraction of raffia palm fiber increased in the formulation. This means that light weight roofing sheets and other construction materials can be made with this formulation. The water absorption decreased with increasing numbers of days of curing while the compressive strength increased as the volume fraction of raffia palm fiber addition increased in the formulation. The low value(s) of water absorption recorded in this work for the polyester modified cement mortar after curing for 28 days is within the recommend standard of 0 to 2% for roofing sheet application.Thermal analysis results showed that the RPFAp composites still retained above 80% of its weight at temperature around 900oC while that of RPF composites still retained above 9% of its weight at temperature around 900oC. Factorial design of the experiment was successfully employed to describe the water absorption and compressive strength of the cement mortar; the developed linear equation model was used in predicting the water absorption and compressive strength of the composites within the selected experimental conditions. Model validation experiments show good correspondents between the actual (4.5%, 3.8% PVA and 4.6%, 3.7% polyester) and predicted (4.8%, 3.6% PVA and 4.5%, 3.7% polyester) water absorption for RPF and RPFAp respectively. This work established that polymer modified raffia palm fiber composites should be used for roofing sheets and that the volume percent of the (RPF and RPFAp) should not exceed 0.2% volume fraction