Thermo-mechanical properties of the blend syndiotactic/atactic polystyrene after crystallization of the syndiotactic polystyrene

Crystallization, Melting and Morphology of Syndiotactic/Atactic Polystyrene Blends: Molecular Weight Effects of Atactic Polystyrene

“…Recently, a number of publications1–5 have focused on the structural characterization of syndiotactic polystyrene (sPS) due to its potential application as an advanced engineering plastic. Although miscibility of sPS with its atactic counterpart (atactic polystyrene, aPS) has been reported and confirmed previously,6–11 work on the effect of aPS molecular weight (MW) on the crystallization behavior of sPS is quite limited. Most articles have focused on sPS systems blended with high MW aPS (50–300k) 6–11.…”

“…Although miscibility of sPS with its atactic counterpart (atactic polystyrene, aPS) has been reported and confirmed previously,6–11 work on the effect of aPS molecular weight (MW) on the crystallization behavior of sPS is quite limited. Most articles have focused on sPS systems blended with high MW aPS (50–300k) 6–11. Previous reports have shown that the aPS component (MW ≈300k) will be segregated to the interfibrillar region of the spherulites,10,11 retarding the sPS crystallization rate,10,12 but does not change the crystalline form of sPS 10,11.…”

Influence of PS‐b‐PEO diblock copolymers on the compatibility of syndiotactic polystyrene modified epoxy blends

“…On one hand, as it was published in our previous study,18 during curing of sPS‐(DGEBA/MCDEA) systems at 220°C, both crystallization of sPS and epoxy polymerization reaction can induce phase separation (CIPS and RIPS, respectively). On the other hand, the addition of PS‐ b ‐PEO results in the compatibilization between sPS and epoxy‐rich phase, because hydrogen bonds are formed between the hydroxyl groups of MCDEA cured epoxy and ether groups of PEO block37, 38 but also as a consequence of partial miscibility between PS block and sPS 11–14. Taking this into account, less spherulites of sPS phase can be produced during phase separation, which occurs mostly by RIPS leading to more amorphous phase of sPS.…”

“…sPS has gained increasing academic and industrial interests since its first successful synthesis in 1985 using a titanium metallocene catalyst as reported by Ishihara et al2 However, because sPS has some disadvantages such as low strength3 and high processing temperature,4 it has been restricted to a few applications. One way to overcome these problems is blending sPS with other thermoplastic polymers, such as poly(vinyl methyl ether) (PVME),5–7 poly(2,6‐dimethyl‐1,4‐phenyle oxide) (PPO),8, 9 poly( p ‐phenylene sulfide) (PPS),10 atactic polystyrene (aPS),11–14 or with epoxy/amine systems 15–19. Blending of polymers provide an efficient way of developing new materials with tailored properties but most of polymer blends are immiscible at molecular level.…”

“…In the present study, a poly(styrene‐ b ‐ethylene oxide) (PS‐ b ‐PEO) diblock copolymer has been used as compatibilizer. It was chosen taking into account both the difficulty in synthesis of diblock copolymer containing sPS block and miscibility between sPS and aPS 11–14…”