Synergistic toughening of polypropylene by thermoplastic starch acetate andSEBS‐MAH

Abstract

The plasticized starch exhibits flexible properties, similar to that of elastomer. In this paper, thermoplastic starch acetate (TPAS) and maleic anhydride grafted poly[styrene-b-(ethylene-co-butylene)-b-styrene] (SEBS-MAH) were used to toughen polypropylene (PP) through melt blending. It is found TPAS and SEBS-MAH have a synergistic toughening effect on PP, especially the notched impact strength of PP/TPAS/SEBS-MAH (70/15/15) blend is as high as 83.4 kJ/m 2 , but only 7.2 kJ/m 2 of that for PP/TPAS/SEBS (70/15/15) blend. The structure-property relationship of the PP/TPAS/SEBS-MAH blends was investigated. Compared with PP/TPAS/SEBS (70/15/15) blend, the TPAS domains are dispersed homogeneously in the PP/TPAS/SEBS-MAH (70/15/15)blend with the domain size of TPAS less than 0.2 μm. The incorporation of SEBS-MAH not only improves the compatibility between PP and TPAS but also facilitates the formation of a core-shell structure with TPAS as the core and SEBS-MAH as the shell. Thus formed core-shell particles play an important role in toughening PP. The spreading coefficient of the multiphase blend reveals that only when the SEBS-MAH content is higher than TPAS, the coreshell structure can be formed. Otherwise, TPAS and SEBS-MAH will disperse separately and the toughness will not be improved. This work provides a new insight into polymer toughening with TPAS.

A Strategy to Develop Homo-polypropylene Composites with High Impact and High Rigidity

“…For example, the core–shell structure of toughened PP can use PE as the core and EPR as the shell, , silicon dioxide-EPDM core–shell particles, and so on. − The addition of core–shell particles and the formation of a ternary blend system, according to the theoretical model proposed by Wu, can simultaneously improve the toughness and reduce the modulus loss in composite materials. Meanwhile, the particular core–shell structure provides more possibilities in selecting the core and shell. − As a typical two-phase modifier, it opens a new path for designing and synthesizing stiffness–toughness balanced materials. Pure inorganic particles have a reinforcing effect on thermoplastic materials, but they do not significantly improve toughness. − To decrease stiffness loss and increase toughness, the preferred method is to use core–shell structures consisting of inorganic particles and elastomers or rubbers to modify thermoplastic polymers.…”

Synergistic effects of in situ fibrillated polytetrafluoroethylene and polystyrene–butadiene block on the microcellular foaming behaviors of polyphenylene oxide modified by high‐impact polystyrene

“…Many studies showed the excellent toughening effect of SEBS in polymer blends. [24][25][26] Jiang et al studied the flame retardant mechanism of SEBS/PPO blends and showed that SEBS could improve their thermal stability by incorporating PPO. 27 Tang et al studied the synergistic reinforcement and toughening of PPO/HIPS materials with GFs as a reinforcing agent and polystyrene butadiene block (SEBS) as a toughening agent.…”