Structure-property correlation of an impact- modified random polypropylene copolymer

Abstract

The combination of rheological and interfacial properties is utilized in this work to explain the thermal and mechanical properties of a random polypropylene copolymer (RPP) toughened with an ethylene-propylene copolymer (EPR). RPP/EPR blends are directly prepared by injection molding. The EPR exhibits higher viscosity in comparison with the RPP over the evaluated shear rate, while the RPP/EPR blends show similar viscosities at high shear rates. The interfacial properties indicate a strong interaction between the RPP and EPR domains. Differential scanning calorimetry analyses indicate that the EPR does not act as a nucleating agent for the RPP, with the RPP crystallinity only decreasing at high EPR contents, suggesting that the EPR can modify the RPP crystallite size. Scanning electron micrographs of the blends demonstrate a ductile fracture surface, indicating that EPR can increase the RPP tenacity. The RPP impact strength is improved by up to 102% in the RPP/EPR 90/10 wt.% blend, while the RPP deformation at break is increased from 183% to 246% after the incorporation of 10% EPR. The tensile strengths of the RPP and RPP/EPR blends are very similar, indicating that the RPP achieves a good balance between stiffness and toughness after being blended with the EPR.

Evaluation of the SEBS copolymer in the compatibility of PP/ABS blends through mechanical, thermal, thermomechanical properties, and morphology

“…Polypropylene (PP) is a thermoplastic widely used in the polymer processing industry to manufacture plastic cups, toys, industrial containers, soft drink lids, packaging, plastic chairs, injection syringes, bags for grain and fertilizers, cutlery, and automotive parts (battery case) 8,9 . The low density, easy processability, recyclability, good mechanical properties, chemical resistance, and low‐cost properties contribute to a diversity of applications 10,11 . However, PP has low impact strength, limiting its application in products that demand high impact effort 12 .…”

Defining the Effect of a Polymeric Compatibilizer on the Properties of Random Polypropylene/Glass Fibre Composites

“…However, the characteristic low impact resistance, poor dimensional stability and relatively low maximum service temperature often limit its suitability for highly demanding applications. Copolymerization of PP with small volumes of different olefin monomers has been seen to greatly benefit the impact strength [10,11] and the thermal properties of polypropylene [12]. Thus, random polypropylene (PP R ) contains up to 10 wt.% ethylene units randomly dispersed into the PP matrix and exhibits high elasticity, good impact and creep resistance and increased longevity.…”

Effect of hydrophobic nano‐silica/β‐nucleating agent on the crystallization behavior and mechanical properties of polypropylene random copolymers

“…Due to the characteristics of high modulus and high rigidity, hydrophobic nano-SiO 2 can be used to improve the strength and scratch resistance of composite materials. [28][29][30][31][32][33][34][35] Although most of the literature deals with the modification of PP-R, the modifications are too homogeneous. Either nucleating agents alone or nanoparticles alone are used, and little attention has been paid to combining nucleating agents with nanoparticles for studying PP-Rs.…”

“…Adding a small amount to PP‐R can change the material properties. Due to the characteristics of high modulus and high rigidity, hydrophobic nano‐SiO 2 can be used to improve the strength and scratch resistance of composite materials 28–35 . Although most of the literature deals with the modification of PP‐R, the modifications are too homogeneous.…”