| Popis: |
Current challenges highlight the need for polymer research using renewable natural sources as a substitute for petroleum-based polymers. In this study, consequently, the fabrication of green polyurethane (PU) foams and its composites is to be demonstrated dependent on synthesis in the laboratory scale of hydroxylated bio-epoxy (B) and petroleum-based synthetic-epoxy (E), crosslinker and wood fillers. Polyurethane foams were modified with two type of wood fiber fillers, powder (P) and flakes (L) with specific percentage ratios of 0, 5, 10, 15 and 20 %wt. Bio-epoxy (B) and synthetic-epoxy (E) foam and its composite were exposed to UV irradiation for a period of 2000 hours and 4000 hours by UV Whetherometer apparatus. The morphology structure and viscoelastic properties such as storage modulus, E’, damping behavior, tan δ and loss modulus, E’’ of E0-5L, E0-20P, B0-20L and B0-20P were measured. The damping behaviour was found to decrease as a function of filler loading and this was attributed to the restricted movement of the polymer segments. It has been observed that the storage modulus and loss modulus of E20L with highest filler ratio achieved the highest value of storage modulus and loss modulus (0.6114 MPa), (0.0812 MPa) respectively, among other filler ratio and different exposure time to UV irradiation. Increasing storage modulus of the composite with the addition filler due to the enhancement in stiffness of the synthetic-epoxy PUs foam. Among others, the bio-epoxy PUs foam (B20P) has the highest storage value (9.077 MPa) and loss modulus (2.452 MPa) showing that bio-epoxy PU foams can dissipate energy faster than syntheticepoxy polymer foams. |
