Reductive Arylation of PVC by Dual-Metal Catalyzed Cross-Electrophile Coupling

Area of Science:

• Polymer Chemistry
• Materials Science
• Organic Synthesis

Background:

• Poly(vinyl chloride) (PVC) is a widely used thermoplastic whose properties rely on additives.
• These additives are often noncovalent and prone to migration and leaching, compromising material integrity.
• Current methods for covalently attaching additives to PVC are limited and do not allow for arylation.

Purpose of the Study:

• To develop a novel, mild, and controllable method for the arylation of PVC.
• To enable the covalent attachment of aromatic additives, such as colorants, antioxidants, and flame retardants, to the PVC backbone.
• To improve the chemical resistance and durability of PVC materials by preventing additive leaching.

Main Methods:

• Electroreductive arylation of PVC using aryl bromides.
• Catalysis of the reaction using a combination of Cobalt (Co) and Nickel (Ni) complexes.
• Application of the method to postconsumer PVC on a multigram scale.

Main Results:

• Successful on-bond arylation of PVC with various functional aromatic architectures.
• The transformation was achieved without causing chain scission in the PVC backbone.
• Arylated PVC materials demonstrated excellent chemical resistance.
• No leaching of the covalently attached aromatic additives was observed.

Conclusions:

• The developed electroreductive arylation provides a versatile and effective route for modifying PVC.
• This method overcomes the limitations of previous grafting techniques, enabling the incorporation of diverse aromatic additives.
• The resulting arylated PVC exhibits enhanced stability and durability due to the prevention of additive leaching, offering improved performance for commercial applications.