In-situ compatibilization, thermal properties and dynamic rheological behavior of PS/LLDPE blends

Polystyrene(PS) and linear low density polyethylene(LLDPE) blends were in-situ compatibilized by the Friedel-Crafts alkylation reaction, and the blends were characterized via Fourier transform infrared spectroscopy analysis, thermal gravimetric analysis and dynamic rheology. The results show that adding 0.4% AlCl3 to PS/LLDPE (80/20, mass ratio)blends can help to produce more PS-g-LLDPE copolymer, and the grafting-percent-ratio is high to 30.9%. The mechanical properties of the compatibilized blends are improved notably compared to that of the mechanical blends, for example, the tensile strength is increased from 14.1 MPa to 20.0 MPa and its elongation at break increases from 4.2% to 12.1%. The thermogravimetric analysis shows the temperature of maximum rate of degradation of the compatibilized blends is raised 11°C. The dynamic rheological properties show that at the low frequency (ω) range, the dynamic storage modulus (G′), loss modulus (G″) and complex viscosity (η*) of the blends by in-situ compatibilization are higher than of the mechanical blends, while the loss tangent (tanδ) is lower than of mechanical blends.