Isotactic polypropylene (iPP) is one of the most widely used general-purpose plastics due to its excellent properties. However, the low impact strength limits its extensive application in the engineering field. Pressureinduced flow (PIF) processing, regarded as an effective and economical technique for improving the mechanical property of polymer materials has been used to prepare iPP/propylene-ethylene copolymer (iPP/PEC) blends with 0, 5 and 20 wt% PEC contents, respectively. With assistance of the PIF processing at 120 ?C with no constraint direction, the iPP/PEC 80/20 blend shows the highest notched Izod impact strength of 66 kJ/m2, about 30 times of that for neat iPP (2.2 kJ/m2), and the tensile strength and Young’s modulus are simultaneously improved to 31 and 890 MPa, respectively. The measurement results from differential scanning calorimetry, scanning electron microscopy, small-angle X-ray scattering, wide-angle X-ray diffraction and dynamic mechanical analysis reveal the effects of the orientation degrees of the iPP crystalline lamellar stacks and the PEC phase domains, reductions in interparticle distance and crystal sizes on improving the impact and tensile strengths. The PIF processing with no constraint direction as reported in this work sounds a promising technique for preparing high-performance polymer blends.

https://doi.org/10.1016/j.polymer.2025.128663