Effect of octene content in poly(ethylene‐co‐1‐octene) on the properties of poly(propylene)/poly(ethylene‐co‐1‐octene) blends

Abstract

Ethylene-octene random copolymer (EOC) is one of the most commonly employed elastomers for PP, and as such its rubber toughening efficiency has been extensively studied. However, most existing studies employ EOC containing an octene comonomer of about 8 mol %. Therefore, in this study, we investigated the effect of EOC octene comonomer content on the morphology and thermal and mechanical properties of PP-ethylene random copolymer (PP-CP)/EOC (80/20 wt %/wt %) blends. It was clearly shown that the properties of the blends are significantly affected by the octene content. The rubber particle size of the blends decreased as the octene content in the EOC was increased, which was a consequence of the reduced interfacial tension between PP-CP and EOC. Impact strength of the blends as a function of octene content displayed a brittle-ductile transition. The tensile yield strength and modulus of the PP-CP/ EOC blends were decreased by addition of EOC, owing to incorporation of the soft EOC into the hard PP-CP. The tensile yield strength and modulus of PP-CP/EOC blends decreased monotonically with the octene content in the EOC. The melting temperature as well as the crystallinity of the PP-CP phase were not affected significantly by the addition of EOC whereas a notable shift in melting and crystallization temperatures was observed for the EOC phase.

Thermoplastic elastomers blends based on linear low density polyethylene, ethylene-1-octene copolymers and ground rubber tire

“…Copolymers with more than 20 wt% of octene are elastomeric and due to the chemical similarity and easy processability can be widely used to toughen polyolefin polymers [17] . There is evidence in the literature that the comonomer content of the metallocene ethylene-α -olefin copolymers has a strong effect on the properties of high impact polypropylene/LDPE blends and on the properties of polypropylene-ethylene random copolymer / EOCs blends [18] . The grades of EOCs used in this work present the same MFI values and different comonomer content (Table 1).…”

“…Lee et al [18] verified in a study of polypropyleneethylene random copolymer (PP-CP) and EOC blends that the rubber particle size decreased as the octene content in the ethylene-α-olefin random copolymer increased. As the rheological properties of all EOCs and PP-CP/ EOC blends were identical, they inferred that interfacial interaction between PP-CP and EOCs increases as the octene content in EOC increases.…”

Extruder‐made TPO nanocomposites. II. Effect of maleated poly(propylene)/organoclay ratio on morphology and thermal expansion behavior

“…Addition of an elastomer, especially metallocene or single‐site catalyzed ethylene‐co‐octene copolymers (EOR), can lead to an improvement in the toughness of poly(propylene) (PP); however, the presence of the elastomer also reduces stiffness and increases CTE . In our previous article, we have shown that PP can be toughened with the elastomer using an organoclay to control elastomer particle size; these extruder‐made TPO nanocomposites can have a good balance of toughness and stiffness .…”

Extruder‐made TPO nanocomposites. I. Effect of maleated polypropylene and organoclay ratio on the morphology and mechanical properties

“…Polypropylene (PP) and organoclay based nanocomposites containing maleated polypropylene have shown significant improvement in the mechanical properties and decreased thermal expansion 2–7. PP toughened with an elastomer, especially metallocene or single‐site catalyzed ethylene‐ co ‐octene copolymers (EOR), leads to an improvement in the toughness; however, the presence of the elastomer reduces the stiffness of the blend 8–35. Blends of PP and elastomer are generally referred to as “thermoplastic olefin” or TPO.…”