Abstract:
Moisture absorption and dimensional stability of materials is one major concern in any
engineering design, as well as in any environment. This is because moisture absorption and poor
dimensional stabilities in any material is capable of leading to the degradation and ultimate
failure of such a material. The purpose of this research however, was to study the moisture
absorption as well as dimensional stability properties of composites made from thermosetting
polymers, reinforced with diorite, sandstone, and cornstalk. Other objectives of the research were
to determine possible applications of the different composite materials as well as determine
which of the thermosetting polymer resins would be most applicable as matrix material. Moisture
absorption was carried out using the long term immersion procedure based on the ASTM D 570 -
98 standard. From the results of moisture absorption, the corn stalk-polyester composite was
found to absorb more moisture than the other synthesized composite. The diorite-polyester
composite absorbed the least moisture and results indicate that moisture decreases with
increasing amount of the diorite filler added. The dimensional stability tests indicate that the
sandstone-polyester composite is the most dimensionally stable of all the composite materials
made in this research, and comparism of this composite with the water based acrylic resinsandstone
composite indicates that the polyester composite is the preferable choice of polymer
resin as matrix material for the production of composites. This conclusion was based on facts
obtained from dimensional stability tests that indicate that the polyester resin is more stable
dimensionally when filled with sandstone. Finally, designs were made from the various
composites and this include table tops made from polyester-diorite composites, wall tiles made
from polyester-sandstone composite, artifacts made from polyester-cornstalk composite, and
wall tiles were also made using the water-based acrylic resin. A cost analysis was also carried
out and although cornstalk was estimated as possible material for production of cost effective
composites but its undesirable properties such as high moisture intake , made the sandstone a
preferable choice of filler material for production of cost effective materials.
