Polyary

Polyary is a term used in polymer chemistry to denote a class of polymers whose backbone is dominated by aryl units. In practice, polyary refers to polymers built from aryl-based repeating units linked through carbon–carbon bonds or via short bridging groups, yielding rigid, highly conjugated chains. The term is often used interchangeably with polyarylene in the literature, and encompasses subfamilies such as polyarylenes and related polyaryl polymers.

Structures typically consist of benzene or other aryl rings connected directly or via short linkers, giving a rigid, conjugated backbone. Physical properties commonly include high glass-transition temperatures and thermal stability, good chemical resistance, and low solubility, which can hinder solution processing but enhance mechanical stiffness and barrier performance. The conjugated backbone can also impart interesting optical and electronic characteristics, though these depend strongly on substitution patterns and the presence of heteroatoms or spacers.

Synthesis methods vary. Steps-growth polymerizations of difunctional aryl monomers using palladium- or nickel-catalyzed cross-coupling (for example Suzuki–Miyaura or Yamamoto-type processes) are common routes, as are oxidative coupling strategies of di-aryl precursors. The choice of substituents on the aryl rings allows tuning of solubility, processability, and electronic properties.

Applications and research directions for polyary polymers include high-temperature engineering plastics, dielectric materials for electronics, and selective membranes. They are also explored as components in organic electronics, such as transistors and optoelectronic devices. Ongoing challenges focus on improving processability without compromising performance, controlling conjugation defects, and reducing synthesis costs. See also polyarylene, polyarylene ether, and conjugated polymers.