Influence of extender oil composition on flowing property, thermal stability, and morphology of styrene‐b‐ethylene‐co‐butylene‐b‐styrene copolymer/polypropylene/oil blends

Abstract

In this study, a series of styrene-b-ethylene-co-butylene-b-styrene copolymer (SEBS)/polypropylene (PP)/oil blends with different kinds of oil composition was developed through melt blending. The effect of oil with different composition and properties on its phase equilibrium and "redistribution" in multiphasic SEBS elastomer was systematically studied for the first time. Moreover, an integral influencing mechanism of oil composition on the structure and properties of SEBS/PP/oil blends was also put forward. The mineral oil was mainly distributed in ethylene/butylene (EB)/PP phase, which greatly enhanced the processing flowability of SEBS/PP/oil blends. With increasing oil C N content, a redistribution of oil appeared and excess naphthenic oil (NO) entered the interphase of soft and hard phases. The dynamic mechanical thermal analysis (DMTA) analysis indicated that the polystyrene (PS) phase was plasticized, which also helped to improve the processing fluidity of blends. However, the plasticizing of physical cross-linking point PS resulted in a decrease in mechanical strength and thermal stability. Small-angle X-ray scattering (SAXS) and transmission electron microscope (TEM) results showed that PS phase (45 nm to 55 nm) cylindrically distributed in EB/PP/oil matrix, the excess NO in the interphase enlarged the distance between PS phase and widen the escape channel for oil migration. At over 45% oil C N content, the electron density difference between soft and hard phases reduced to the minimum, same as T gPS , indicating a deeper plasticizing effect. The PS phase swelled and exhibited elastic behavior; thus, the force could be uniformly transferred between two phases. Importantly, a recover in strength and thermal stability was observed in O-5 blend.This work significantly filled the gap of studies in oil-extended thermoplastic elastomers (TPEs), exhibiting great theoretical guiding significance and application value.

Structure and performance of hydrogenated styrenic block copolymers/polypropylene/oil (HSBCs/PP/oil) composites

“…The lowest migration rate and the highest initial decomposition temperature of SEEPS, the reason was also related to its structure. It is known that oil molecules are distributed in the soft phase, 35 SEEPS composite has the largest soft phase (48.7 nm), the oil molecules have more space without being squeezed out. Besides, PP crystals zone (39.9% crystallinity) will also hinder the migration of oil molecules.…”

“…As is well known, the d-spacing is related to phase spacing. 35 The larger the dspacing value, the bigger the size of the soft phase.…”

Synthesis of novel polycarbonate‐based thermoplastic polyurethane elastomers compatibilizers with octadecyl side chains and their application in PC/PP blends

“…Polymer blending is a useful method to overcome the performance defects of a single polymer and obtain low‐cost polymeric materials with excellent properties 1‐4 . As one of the most common engineering plastics, polycarbonate (PC) has been widely used in numerous fields, such as automobile manufacturing, mechanical equipment, electronic and electrical equipment, medical equipment, and precision instruments, due to its good mechanical properties, high‐temperature resistance, transparency, dimensional stability, and other excellent characteristics 5‐7 .…”

Elastic melt-blown nonwoven fabrication of styrene‐ethylene/butylene‐styrene copolymer and polypropylene blends: a study of morphology and properties

“…21,27 The poly(ethylene/butylene) domain has a similar molecular structure to PP, which provides partial compatibility. 27,28 At present, the research into SEBS has been mainly focused on improving the toughness of PP or the compatibility between PP and other polymers as the modifier or compatibilizer. 29,30 However, there are few papers devoted to the spinnability and the preparation of elastic melt-blown nonwovens based on SEBS and PP blends.…”

“…21 Styrene-ethylene/butylene-styrene copolymer (SEBS) is a kind of SBC that has been researched for several decades due to its excellent properties, which include good elasticity, ultraviolet (UV) light resistance, ease of processability, and high thermal stability. 21,27 The poly(ethylene/butylene) domain has a similar molecular structure to PP, which provides partial compatibility. 27,28 At present, the research into SEBS has been mainly focused on improving the toughness of PP or the compatibility between PP and other polymers as the modifier or compatibilizer.…”