Polymeric Blends Based on Syndiotactic Polystyrene

Polimeri Europa SpA Istituto Donegani, Novara, Italy 

To improve the ultimate properties of sPS, blending with other polymeric materials is a commonly applied technique and the literature on this topic has steadily increased in recent years. In this chapter the physical and mechanical properties of blends based on sPS and the patents relevant to their preparation and applications are reviewed and discussed. 

Some typical physical and mechanical properties of sPS are reported below some reported values, e.g. the melting temperature [3], can vary slightly for 

Modern Styrenic Polymers Polystyrene and Styrenic Copolymers. Edited by J. Scheirs and D. B. Priddy t 2003 John Wiley Sons Ltd 

Izod impact strength (notched) Tensile strength Tensile modulus Elongation at break Flexural modulus Flexural strength 

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Poly(cyclohexyl acrylate) was shown to be miscible with PS with ucst behavior [720]. Random copolymers of cyclohexyl acrylate with n-butyl acrylate showed miscibility with PS above 50% cyclohexyl acrylate[721]. Poly(cyclohexyl methacrylate)/isotactic PS blends showed miscibility based on calorimetry and NMR studies [722]. The NMR results showed homogeneous behavior at a scale of 2.5-3.5 nm. Poly(4-trimethylsilyl styrene) miscibility with polyisoprene was observed with a lest behavior (critical temperature = 172 ° C at degree of polymerization of 370) [723]. The interaction parameter, showed the following relationship = 0.027—9.5/T. Isotactic and syndiotactic polystyrene both exhibit crystallinity, whereas atactic polystyrene is amorphous. Atactic PS/isotactic PS blends exhibited crystallization kinetics, which decreased linearly with atactic PS addition indicating miscibility [724]. The TgS of aPS and iPS are identical, thus Tg methods could not be employed to assess miscibility. Atactic PS/syndiotactic PS blends were also noted to be miscible with rejection of atactic PS in the interfibrillar region between the lamellar stacks of sPS [725]. 

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