Abstract:
Natural fibers have drawn a lot of interest for the use of reinforcing materials in composites as a
sustainable and renewable resource. By adopting a compression molding technique and varying
fiber contents (5, 10, 15, 20 and 25 wt%), short date palm mat (DPM) fiber reinforced HDPE and
polystyrene (PS) composites were prepared. Physical, mechanical, structural, thermal,
morphological, and biodegradation properties were examined. 10% DPM fiber reinforced
composites exhibited optimum mechanical properties. The DPM fibers were subjected to
different percentages of NaOH treatment to enhance the fiber-matrix adhesion. The maximum
value of mechanical properties was attained for the composites treated with 5% NaOH. ZnO
nanoparticles as nano filler was also used to improve the mechanical properties of the
composites. The composites with 3% ZnO nanoparticles showed highest mechanical properties.
The produced optimized samples were exposed to various gamma radiation doses, and the results
for all types of composites were best when exposed to 5 kGy of gamma radiation. Further, three
fire retardant additives namely, monosodium phosphate, monoammonium phosphate and
magnesium hydroxide were used in the composites and monoammonium phosphate displayed
best fire retardant properties. A biodegradable composite was developed using various
percentages of DPM fiber and polylactic acid (PLA). 10% DPM fiber reinforced PLA composite
presented highest results. A hybrid composite was made using date palm mat (DPM) and
palmyra palm fruit (PPF) fiber with HDPE matrix. A hybrid composite with 5% fiber content
achieved better properties. Crystalline nanocellulose were extracted from DPM fibers and used
to prepare nanocomposite films. 9% crystalline nanocellulose containing nanocomposite films
revealed highest mechanical properties. The characteristics of these newly created composites
indicate potential applications in various fields.
Description:
A Thesis Submitted to the Department of Applied Chemistry and Chemical Engineering, University of Dhaka, in Partial Fulfilment of the Requirements for the Degree of Doctor of Philosophy (PhD).
