Effect of Short Fiber Reinforcement on Mechanical Properties of Hybrid Phenolic Composites

Abstract

Fiber plays an important role in determining the hardness, strength, and dynamic mechanical properties of composite material. In the present work, enhancement of viscoelastic behaviour of hybrid phenolic composites has been synergistically investigated. Five different phenolic composites, namely, C1, C2, C3, C4, and C5, were fabricated by varying the weight percentage of basalt and aramid fiber, namely, 25, 20, 15, 10, and 5% by compensating with barium sulphate (BaSO4) to keep the combined reinforcement concentration at 25 wt%. Hardness was measured to examine the resistance of composites to indentation. The hardness of phenolic composites increased from 72.2 to 85.2 with increase in basalt fiber loading. Composite C1 (25 wt% fiber) is 1.2 times harder than composite C5. Compression test was conducted to find out compressive strength of phenolic composites and compressive strength increased with increase in fiber content. Dynamic mechanical analysis (DMA) was carried out to assess the temperature dependence mechanical properties in terms of storage modulus (E′), loss modulus (E′′), and damping factor (tan δ). The results indicate great improvement of E′ values and decrease in damping behaviour of composite upon fiber addition. Further X-ray powder diffraction (XRD) and energy-dispersive X-ray (EDX) analysis were employed to characterize the friction composites.

Dynamic Mechanical Analysis of Treated and Untreated Sugar Palm Fibre-based Phenolic Composites

“…On the other hand, no notable changes were shown with respect to the rubbery state of the SPF/PF composites for all filler loadings. The results that were obtained were in agreement with the findings of other researchers (Bachtiar et al 2012;Essabir et al 2016;Jawaid et al 2013;Manoharan et al 2014).…”

“…The high values of Tg could be associated with the decreased mobility of the matrix chain caused by the addition of the SPF filler and indicate a good interaction between the SPFs and the phenolic matrix. Moreover, the highest value of the Eʺ maximum was observed for 30% vol., suggesting that an increased fibre loading would increase the internal friction and improve the energy dissipation (Manoharan et al 2014). The results that were obtained were also in line with the findings of other researchers (Sreekala et al 2005;Saba et al 2016b).…”

“…Figure 3 illustrates the variation in the loss modulus of the SPF filler in the phenolic composites with temperature. The glass transition occurred when the storage modulus decreased rapidly and the loss modulus reached a maximum value (Bachtiar et al 2012;Manoharan et al 2014;Saba et al 2016a). All loss modulus curves reached the maximum values for the dissipation of the mechanical energy and decreased at higher temperatures as a result of the free movement of the polymer chain.…”

“…The interlocking bonding of the fibre-matrix and composites' curing behaviour can be analysed from the damping factor (Manoharan et al 2014). Figure 4 displays the effect of the SPF filler in the phenolic composites on the damping factor.…”

“…The temperature at which polymer materials change from a glassy to a rubbery state is defined as the glass transition temperature. The homogeneous, heterogeneous, and changes in material structure occurring in polymer composites can be described by a Cole-Cole plot (Goriparthi et al 2012;Manoharan et al 2014).…”