شكل شناسي و خواص ريولوژيكي ، گرمايي و گرمامكانيكي آميخته هاي پلي پروپيلن و پلي اتيلن ترفتالات

Morphology and Rheological, Thermal and Thermomechanical Properties of PP/PET Blends

Preparation of maleic anhydride-grafted polypropylene (PP-g-MA) as compatibilizer and the preparation of the blends of polypropylene and polyethylene terephthalate by catalyzed reactive blending in a co-rotating twin screw extruder using para-toluene sulphonic acid as catalyst were investigated. IR spectroscopy and titration results confirmed the successful melt grafting. The effects of compatibilizer on rheological, thermal, and thermomechanical properties and the morphology of PP/PET blends were also studied. The percentage of PET in all blends was fixed at 20% and the compatibilizer content was changed 5-15%. Rheological studies showed that the viscosity of PP was decreased upon melt grafting. This is due to chain scission and decrease in molecular weight. The non-compatibilized and compatibilized blends Theologically behave very similar to PET (lower viscosity component). It means that the viscosity of blends decreased on the addition of the compatibilizer. The DSC results showed that melt grafting has a significant effect on increasing the PP crystallinity. Thermomechanical studies showed that by grafting MA on PP, the storage modulus was increased, whereas, the loss modulus decreased. The SEM micrographs showed that the inter-facial interactions significantly were improved by addition of small amounts of the compatibilizer. A sharp decrease in the size of minor phase inclusions was also observed. The interface was saturated with 10% compatibilizer. The compatibilizer was very successful in improving the properties of blends.