Mechanical Behavior of Polyurethane Composite Foams from Kenaf Fiber and Recycled Tire Rubber Particles

Abstract

In the present work polyurethane foams containing various content loadings of kenaf fiber and recycled tire rubber particulates were prepared and studied, with the objective of developing alternative composite rigid foams. The influence of the filler content on the foam microstructure and its physical and mechanical behavior has been studied for three different polyurethane resin densities. Microstructural observation on fracture surface of composites was carried out using scanning electron microscopy. It has shown closed spherical cells with reduced size when the fillers are added. Nevertheless, the incorporation of kenaf fiber and recycled tire rubber particulates that refined at 80 mesh led to higher mechanical properties than that unfilled polyurethane foam. A 6% filler content loading exhibited the optimum compression stress and compression modulus, while further increase of filler content loading resulted in decline in mechanical behavior. The presence of larger filler content deteriorated the polyurethane system cellular structure and lead to poor composites strength. Overall, the use of kenaf fiber and recycled tire rubber particulates gives composite foams with comparable mechanical behavior for the studied filler reinforcement level.

Effect of partial replacement of kenaf by empty fruit bunch (EFB) on the properties of natural rubber latex foam (NRLF)

“…The density of kenaf is 1.62 g/cm³, which is higher than EFB (1.52 g/cm³) (Anuar et al 2018). Subramaniyan et al (2013) reported that the density of the filler affects the density of the foam. The foam filled with kenaf had a higher density than the one filled with EFB.…”

“…The stem and bark of the kenaf have distinct qualities and can be used in various products, for example, car accessories, animal feed, biofuels, and paper-based products (Ismai et al 2011). Kenaf has been established in Malaysia as a new industrial crop with high potential for product development (Subramaniyan et al 2013).…”

Phase morphology, mechanical, and thermal properties of fiber-reinforced thermoplastic elastomer: Effects of blend composition and compatibilization

“…As shown in Figure 2(a), the rHDPE pellets were introduced through the main feeder (zone 1), while the RR particles (35,50,65, and 80 wt.%) were introduced via a side-stuffer located in zone 4 of the extruder to limit thermal degradation. Then, different concentrations of RR particles (15,30,45, and 60 wt.%) were dry-blended with RTF (20 wt.%) after being oven-dried at 70°C for 12 h. Again, the rHDPE was fed to the extruder in the first zone (main feed), while the RR/RTF mixtures were fed via the side feeder (zone 4). The processing temperature was fixed at 175°C with a screw speed of 120 r/min and a flow rate of 4 kg/h.…”

“…Again, the materials were cooled in a water bath and pelletized. Then, these pellets (RR/MAPE masterbatch) were introduced in the main feeder at different concentrations (15,30,45, and 60 wt.%) along with rHDPE (65, 50, 35, and 20 wt.%) in a second extrusion step, while the RTF (20 wt.%) was introduced via the side-stuffer located at zone 4. All the formulations with codes are presented in Table 2.…”

“…13 But the low affinity of short fiber and crosslinked rubber particles toward several polymer matrices contribute to high surface energy and phase incompatibility leading to poor elongation at beak and impact strength due to insufficient interfacial bonding. 14,15 Once good adhesion is obtained, the incorporation of fibers can lead to increased tensile and flexural properties of the composites. 7 For example, Kakroodi et al 16 observed that the tensile modulus of recycled polypropylene (rPP)/GTR (80/20) blends was improved by 25% (from 320 to 400 MPa) after the incorporation of 20 wt.% birch wood flour.…”