Doctor Thesis
DESIGN, PROCESSING AND CHARACTERIZATION OF JUTE AND
PALM NATURAL FIBERS SANDWICH COMPOSITE PANELSAHMED ELSAYED ABDELFATTAH ELBADRY
Abstract
The strict environmental regulations have faced the composite industry to findalternatively eco-friendly reinforcements and resin systems to produce environmentallyfriendly composite materials. Therefore, the objectives of this work are to investigate
the effect of jute and glass skin layers on the mechanical, impact properties and notch
sensitivity of jute and palm mats reinforced unsaturated matrix composites. Theobjectives of chapter 2 and 3 were to investigate the effect of jute fiber weight contents
of jute mat composites (JMC) on the mechanical properties including the tensile,bending, impact properties and the notch sensitivity. Moreover, the effect of the scratchwith different scratch loads on the drop weight impact properties of JMC compared toglass mat composites (GMC) has been investigated and the fracture behavior of thecomposites was also examined. The results showed that as the jute fiber weight content
increases, the mechanical and impact properties of JMC increase. The impact energy ofJMC and GMC is improved by adding scratch to the tension side of the specimen. The
fracture surface of JMC indicates that the radial matrix cracks are trapped and arrested
and constraint to propagate a long a weak preferable path (scratch path) and so suppress
any tendency of crack branching out of the scratch path. By adding the scratch to thetension side of GMC for different scratch loads, the crack deflection and delamination
propagate along the weak preferable path (scratch path) and so the area of the crack
increases and this dissipates most of the impact energy and so the impact energy isimproved. Moreover, the notch sensitivity of JMC composites decreases by increasing
the fiber weight content and the characteristic distance which represents the distancefrom the hole boundary at which the brittle fracture starts to occur is validated to be
substitute for the material properties for JMC instead of fracture toughness value.
Chapter 4 and 5 investigate the effect of skin fabrics (jute and glass fabrics) on themechanical properties and notch sensitivity of hybrid composites. The results indicatedthat by adding the jute and glass cloths as skin layers, the tensile and bending properties

of hybrid composites were significantly improved compared to those of neat resin andJMC while the notch sensitivity of hybrid composites increases compared to that ofJMC. Moreover, Moreover, by adding the jute and glass cloths as outer and inner skinlayers, the izod impact strength and the total impulse impact energy were improved
compared to those of neat resin and JMC. Chapter 6 investigate the mechanicalproperties of palm mat composites (PMC) composites and the effect of skin fabrics (juteand glass fabrics) on the mechanical and impact properties of palm mat composites. The
results indicated that the mechanical properties of PMC are very weak compared tothose of the neat resin because the interfacial properties between the palm fiber and thematrix are very weak due to the presence of SBR binder which prevents the palm fiber
to be wetted by the matrix for different fiber weight contents. Moreover, by adding thejute and glass cloths as outer and inner skin layers, the mechanical properties wereimproved compared to those of PMC and the neat resin. Moreover, the effect of thepalm fiber has more significant effect on the improvement of the impact properties of
PMC than that of tensile and bending properties compared to those of neat resin and byadding jute and glass cloth as skin layers the total impulse impact energy and the izod
impact strength were significantly improved compared to those of neat resin and PMC.