Bismuth Metallo(co)polymers as Tailored High Refractive Index and Thermoplastic Materials

This study investigated the synthesis and characterization of bismuth metallo(co)polymers of 4-(di-p-tolylbismuth)styrene (DTBS) and 4-(diphenylbismuth)styrene (DPBS) with 4-methylstyrene and 4-bromostyrene. The copolymers derived from DTBS have improved solubility in organic solvents relative to DPBS copolymers; the low solubility is a common limitation of metallopolymer-based materials. The refractive indices of the copolymers were proportional to the content of the bismuth-bearing monomer, with a maximum value of 1.67 at 589 nm corresponding to the DTBS homopolymer. The synthesized copolymers had low Mw values ranging from 1.6 to 5.5 kDa. The materials showed good thermal stability up to 199 °C. The synthesized copolymers are suitable for optical applications due to good solubility, high refractive index, and thermal stability.