Engineering of Syndiotactic and Isotactic Polystyrene-Based Copolymers via Stereoselective Catalytic Polymerization

Abstract

This contribution presents an updated overview of the different copolymers containing stereoregular polystyrene blocks. Special emphasis is placed on syndiospecific and isospecific copolymerization of styrene with co-monomers (ethylene and α-olefins, conjugated and non-conjugated dienes, styrene derivatives, etc.). The catalytic systems involved are described and the polymerization mechanisms are discussed. Alternative approaches (simultaneous, living, chain-transfer and graft copolymerization) and the resulting detailed structures and characteristics of the copolymers are also reported.

Stereochemical enhancement of polymer properties

“…The modulation of stereochemistry for polystyrene-polybutadiene (SB) based polymers is well described for both the PB segment (cis/trans) and styrenic section (tacticity), but full characterisation that seeks to relate material properties to microstructure and stereochemistry is often absent. 241 There are a number of reports on stereocontrolled SB based polymers that describe thermal properties, but these studies are particularly aimed at altering polymer properties according to microstructure and/or relative block length as opposed to changing the stereochemistry of the respective block(s). 229,[242][243][244][245][246][247][248] Furthermore, a description of mechanical properties is missing for these systems.…”

Stereoselective Copolymerization of Styrene with Terpenes Catalyzed by an Ansa-Lanthanidocene Catalyst: Access to New Syndiotactic Polystyrene-Based Materials

“…However, its processability is limited by its high melting point and its brittleness. Syndioselective copolymerization of styrene with small amounts of a second monomer is one of the most common ways to tune the properties of sPS, and thus to improve its processability [9][10][11]. A few examples of styrene-myrcene polymers have already been reported, mostly via anionic or radical copolymerizations [12][13][14].…”

Syndioselective Polymerization of Vinylnaphthalene

“…Precise control over stereo‐configurations of synthetic polymer chains has attracted considerable research interest of polymer chemists from both academia and industries, because the stereoregulated polymers possess different chemical and physical properties from their atactic analogues . For instance, syndiotactic polystyrene becomes one kind of engineering plastic featuring high melting point ( T m = 270 °C), extremely high crystallization rate, and excellent chemical resistance, endowed by the syndiotactic configuration of polymer backbone . Thanks to the invention of the half‐sandwich titanium catalyst that realizes high catalytic activity and syndioselectivity for styrene polymerization .…”

“…[1][2][3][4][5][6][7][8][9][10][11][12][13] For instance, syndiotactic polystyrene becomes one kind of engineering plastic featuring high melting point (T m = 270 °C), extremely high crystallization rate, and excellent chemical resistance, endowed by the syndiotactic configuration of polymer backbone. [4,[14][15][16] Thanks to the invention of the half-sandwich titanium catalyst that realizes high catalytic activity and syndioselectivity for styrene polymerization. [17,18] Since then, extensive studies have been devoted to develop efficient "single-site" catalytic systems for stereospecific polymerization of styrene and its derivatives, and various homogeneous metallocene, half-metallocene, and non-metallocene group 3 and 4 metal-based catalysts have been invented.…”