SBS and SEBS block copolymers as impact modifiers for polypropylene compounds

Abstract

Blends of polypropylene (PP) and thermoplastic elastomers (TPE), namely SBS (styrene-butadienestyrene) and SEBS (styrene-ethylene/1-butene-styrene) block copolymers, were prepared to evaluate the effectiveness of the TPE type as an impact modifier for PP and influence of the concentration of elastomer on the polymer properties. Polypropylene homopolymer (PP-H) and ethylene-propylene random copolymer (PP-R) were evaluated as the PP matrix. Results showed that TPEs had a nucleating effect that caused the PP crystallization temperature to increase, with SBS being more effective than SEBS. Microstructure characterization tests showed that in most cases PP/ SEBS blends showed the smallest rubber droplets regardless of the matrix used. It was seen that SEBS is a more effective toughening agent for PP than SBS. At 0°C the Izod impact strength of the PP-H/SEBS 30% b/w blend was twofold higher than the SBS strength, with the PP-R/SEBS 30% b/w blend showing no break. A similar behavior on tensile properties and flexural modulus were observed in both PP/TPE blends. Yield stress and tensile strength decreased and elongation at break increased by expanding the dispersed elastomeric phase in the PP matrix.

Influence of a nucleating agent on the crystallization behaviour of isotactic polypropylene and elastomer blends

“…It has also been observed in iPP blends with other elastomers such as EPR, although in this case the nucleation was related to partial compatibility between components [32,40]. In a very recent study [18], DSC results showed that the presence of SBS and SEBS had a nucleating effect causing an increase in the crystallization temperature of iPP, in agreement with our results. On the other hand, the iPP/EO blends showed a decrease in crystallization rate for each T c compared with pure iPP (Fig.…”

Enhancing the PLA Crystallization Rate and Mechanical Properties by Melt Blending with Poly(styrene-butadiene-styrene) Copolymer

“…Blends of high-impact polystyrene (HIPS) and SBS have been studied with recycling in view, and HIPS/SBS 90/10 blends exhibited the most favorable mechanical properties [13] . Forte et al used thermoplastic elastomers (TPEs), namely SBS and SEBS (styrene-ethylene/1-butene-styrene) block copolymers, as impact modifiers for polypropylene (PP) compounds, and the results indicated that TPEs increased the impact strength of PP and produced a nucleating effect that caused the PP crystallization temperature to increase, with SBS being more effective than SEBS [14] . Pessan et al studied the toughening process of poly(butylene terephthalate) (PBT) by blending it with SBS in the presence of poly(styrene-ran-glicydil methacrylate)(PS-GMA) as the reactive compatibilizer.…”

Thermal behaviors and flame retardancy of novel flame‐retardant, oil‐filled styrene–ethylene–butadiene–styrene block copolymer–polypropylene materials

“…O‐SEBS–PP can be used to prepare automotive interiors. It satisfies the lightweight requirements of automobiles and meets the soft‐touch requirements of high‐level automotive interiors . However, O‐SEBS–PP material is easily burned.…”

“…It satisfies the lightweight requirements of automobiles and meets the soft-touch requirements of high-level automotive interiors. [6][7][8] However, O-SEBS-PP material is easily burned. However, the molten material drips during the combustion process, and this produces a large amount of smoke.…”