Effect of calcium carbonate on the mechanical properties of polyethylene terephthalate/polypropylene blends with styrene-ethylene/butylene-styrene

The effect of CaCO 3 on the mechanical properties of polyethylene terephthalate/polypropylene (PET/PP) blends with styrene-ethylene/butylene-styrene (SEBS) as a compatibilizer was investigated. Samples with different compositions of PET/PP/CaCO 3 blend were prepared by injection molding method with CaCO 3 content of 0, 2, 4, 6, 8 and 10 wt%. The ratio of PET/PP was fixed at 90/10, while compatibilizer SEBS had a fixed ratio of 5%. The samples were formed according to the ASTM D638, ASTM D790, and ISO 868 standards. The results show that adding 2% of CaCO 3 helps to improve the mechanical properties of the plastic sample. Specifically, tensile strength and the flexural strength increase as CaCO 3 increases from 0 to 2%. With 2% of CaCO 3 , the tensile strength and the flexural strength gain the highest value of 34.79 MPa, and 60.59 MPa, respectively. However, if the sample content is more than 4% CaCO 3 , both the tensile strength and the flexural strength will experience a decline as the percentage of CaCO 3 rises. The SEM microstructure indicates that CaCO 3 particles are well dispersed on the PET substrate. Additionally, the number of particles increases when enhancing the CaCO 3 content in the blends.