*Dynamic Mechanical Behaviour of Coir and Coconut Husk Particulate Reinforced Polymer… DOI: http://dx.doi.org/10.5772/intechopen.82889*

strength of the composites reduced with an increase in exposure time with the effect of exposure to the alkaline solution more pronounced than that noticed for the acidic solution. Stamenović et al. [22] investigated the influence of corrosive environments (acidic and alkaline) on the tensile characteristics of glass FRP pipes. It was shown that increasing the pH value of the alkaline solution further degraded the mechanical integrity of the pipe samples, while the samples subjected to the acidic solution provoked an increase in tensile strength and modulus, and decreasing pH values led to a more significant increase. These results from the study of Stamenović et al. [22] corroborate findings of Sindhu et al. [17], where the effects of various corrosive conditions on the mechanical properties of GFRP were investigated. The tensile strength and modulus increased as residence time in acidic solution increased.

On the other hand, Tripathy [23] studied the mechanical properties and interfacial properties of jute fiber filled epoxy resin. It was observed that the moisture intake by natural fibers, insufficient adhesion between untreated fibers and the polymer matrix, led to fiber pull-out with time [24]. Gilbert and Lee [25] investigated the influence of environmental conditions on the mechanical properties of short fiber reinforced composites. The relationship between moisture, acid, and alkali attacks were determined and the chemical properties were evaluated. Potts et al. [26] investigated the tensile properties of short coir reinforced composites. The tensile characteristics were found not to be dependent of fiber length, although the ultimate tensile strength showed some improvement at 10 mm fiber length.

Despite the volume of fiber reinforced polymer composites under investigation, most of the research efforts have been focused on either the characteristics of these polymers or the basic properties of the different phases that make up the composite [12, 27–29]. In our previous work [12, 30], we identified a coir length which enhanced the mechanical and dynamic mechanical (viscoelastic) properties of our developed coconut husk filled composites. Hence, the present work focused mainly on the evaluation of the dynamic mechanical characteristics of the fabricated composite on exposure to an acidic environment. We have considered dynamic mechanical properties of the samples at low temperatures where polymer molecules are tightly compressed and where the first solid-state transitions occur.
