Influence of Blending on Mechanical Behavior of Low-Density Polyethylene, Polypropylene, Polyvinylchloride

Abstract

Three thermoplastic polymers, low-density polyethylene (LDPE), polypropylene(PP), and polyvinyl chloride (PVC),were synthesized from their raw pellets.Three blends of 1:1 wt.% of low-density polyethylene/polypropylene, low-density polyethylene/polyvinylchloride, polypropylene/polyvinylchloride, and one blend of 1:1:1 wt.% of low-density polyethylene/polypropylene/polyvinylchloride were produced via compression mould method using Two-roll Mill machine and Compression Mould machine. Using the Tensile Strength Tester machine, the pristine polymer and the blends were cut into dumbbell shapes for mechanical testing. The resultsobtained are 9.8MPa and 67.5% maximum stress and strain, respectively, for LDPE, 29MPa, and 12.4% maximum stress and strain, respectively, for neat PP. 25.8MPa and 35% maximum stress and strain respectively for pristine PVC, 19.2MPa and 44% maximum stress and strain respectively for LDPE/PVC blend, 19MPa and 29% maximum stress and strain respectively for LDPE/PP blend, 27.5MPa and10.75% maximum stress and strain respectively for PP/PVC, 21MPa and 10.4% maximum stress and stain respectively for LDPE/PP/PVC blend. The force at peak and the respective peak elongation are; 85.612N and 0.008387m for pristineLDPE, 344.810N and 0.004810m for pristinePP, 264.976N and 0.005496m forpristine PVC, 188.288N and 0.005980m for LDPE/PVC blend, 174.755N and 0.005109m for LDPE/PP blend, 250.196N and0.004287m for PP/PVC blend, 275.175N and 4.009mm for LDPE/PP/PVC blend. The maximum energies expended to have maximum extension are 0.71802784J (LDPE), 2.04578339J (PP), 1.70308635J (PVC), 1.12596224J (LDPE/PVC),0.8928233J (LDPE/PP), 1.50129025J (PP/PVC) and 1.10317658J (LDPE/PP/PVC). These results show improvement in the mechanical properties of the blends when compared with those of the constituent polymers. It also indicatesthat polymeric properties modification via an immiscible polymer blend is possible and easy to achieve.