Synthesis and characterization of benzoylated syndiotactic polystyrene

Gold-Catalyzed Precise Bromination of Polystyrene

Modification of commodity aromatic polymers is highly desirable for accessing materials with new properties. The long-standing challenge for such approaches lies in the development of catalytic methods that can functionalize the aromatic polymers with high precision while preserving the molecular weight and distribution of the starting polymers without any alteration. Herein, we report a highly efficient AuCl₃-catalyzed site-selective aromatic C-H halogenation of polystyrene. The most important feature of this method is that the degree of halogenation can be precisely controlled by simply changing the loading of the halogenating agent, thus allowing the tuning of functional group density in an accurate and predictable manner. Various functional groups, including NH₂ and Bpin, can be installed through effective derivatization of the resultant brominated polystyrene, thus making the method a valuable strategy for the synthesis of value-added materials with tailored properties.

Syndiospecific Coordination Polymerization of Si-H-Containing Styrenes Catalyzed by Scandium Complex and Synthesis of Styrene-Based Triblock Copolymers

The controlled syndiospecific polymerization of three Si-H-containing styrenes, that is, 4-(methylhydrosilyl)styrene (FSt-1), 4-(dimethylhydrosilyl)styrene (FSt-2) and 4-(diisopropylhydrosilyl)styrene (FSt-3), is realized in the presence of (C₅ Me₄ SiMe₃ )Sc (CH₂ C₆ H₅ )₂ (THF)/[Ph₃ C][B(C₆ F₅ )₄ ]. Then a series of FSt-b-styrene-b-FSt triblock copolymers (FSt-St-FSt) are synthesized facilely via a sequential monomer feeding process (FSt-2, styrene, and FSt-2, respectively) during the polymerization. The syndiotactic polystyrene (sPS) block in the middle endows the copolymer with high melting point above 250 °C, whereas the Si-H groups on monomer FSt-2 introduce functional pendants to the end-blocks (with Si-H content of 31-63 mol%). Finally by a mild and high-effective hydrosilylation reaction, novel polar-group functionalized sPS is obtained.

Copolymerization of propylene with styrene and ethylene by a THF-containing half-sandwich scandium catalyst: efficient synthesis of polyolefins with a controllable styrene content

A novel family of multi-block propylene–styrene copolymers with syndiotactic styrene–styrene blocks and random propylene–ethylene–styrene terpolymers with a broad composition range were obtained by using (C₅Me₄SiMe₃)Sc(CH₂SiMe₃)₂(THF).

Recent progress in the chemical modification of syndiotactic polystyrene

This review provides a snapshot of recent progress in the chemical modification of syndiotactic polystyrene.