Mechanical Properties, Morphological Characterization and Melt Dripping Studies of Polypropylene (PP) + High Density Polyethylene (HDPE) + Polystyrene (PS) Ternary Polymer Blends: Non-Isothermal Degradation Kinetics of Compatibilized and Uncompatibilized Blends

Polymer composites have been widely used due to its light weight, performance with good mechanical properties, corrosion resistant, solvent resistance and it becomes an important part of the industries. Polypropylene (PP), polystyrene (PS) and high-density polyethylene (HDPE) are applied to various commercial as well as automobile spare parts. In this study PP, PS and HDPE were melt mixed together to form a ternary polymer blend and mechanical, morphological, thermogravimetric analysis were conducted to determine its potential applications. The compatibilization of the blend was achieved by the combination of ethylene-propylenediene- monomer (EPDM) and styrene-ethylene-butylene-styrene (SEBS). Model free methods like Flynn Wall Ozawa (FWO), Kissinger-Akahira- Sunose equation (KAS) and Friedman methods were applied to estimate the activation energy values at different heating rates of 5, 10 and 15 ºC/min. The compatibilized blend of 80PP/5PS/15HDPE with 5% SEBS/EPDM showed better tensile strength compared to uncompatibilized. Freidman method produced a higher value of average activation energy as 203.4 kJ/mol. The melt dripping characteristics was also analyzed were the time to ignition and time for first drip was found to be in the range of 6 to 9 s and 14-16 s. Pure and compatibilized blends showed a very low limiting oxygen index (LOI) values as in the range of 18.7 to 18.9. Elastomeric/rubber blend compatibilization was achieved and the material can be applied to light weight automobile applications. From morphological characterization, it was understood that compatibilized blends are more durable and easily transfer the stress uniformly through the interface. This compatibilized blend can also be used in low temperature regions.