Architecturally and Chemically Modified Poly(1,3‐cyclohexadiene)

Abstract

Star‐shaped, star‐block‐linear, and hyperbranched poly(1,3‐cyclohexadiene) (PCHD) (co)polymers were synthesized through a convergent living anionic polymerization process or via addition of divinylbenzene. Chemical modification of star‐shaped PCHDs, including aromatization, hydrogenation, fluorination, and sulfonation, was carried out in order to manipulate the physical and thermal properties of these materials. The obtained (co)polymers were characterized by gel permeation chromatography, 1H NMR, DSC, and thermal gravimetric analysis in order to elucidate their molecular weights, molecular weight distributions, chemical nature, and physical and thermal properties. The synthetic approaches described herein offer routes to novel structure and functionality in PCHD‐based materials.magnified image

How well can renewable resources mimic commodity monomers and polymers?

“…Anionic, free-radical, and transition metal catalyzed polymerizations are common methods for polymerizing 1,3-CHD. [90][91][92][93][94][95] Anionic polymerization methods result in microstructures with 1,2 and 1,4-linkages whereas certain metal-based catalysts can produce predominately 1,4-linkages. The presence of 1,4-sequences in the polymer can serve as a precursor to polyparaphenylene.…”

Hydrocarbon-based fuel cell membranes: Sulfonated crosslinked poly(1,3-cyclohexadiene) membranes for high temperature polymer electrolyte fuel cells

“…The in-chain six-member ring structure of PCHD imparts a semi-flexible character to PCHD, with higher glass transition temperatures (>100 C) and better thermal stability as compared with typical polydienes [15e18]. The double bonds in the ring structure of PCHD can be chemically modified through a host of reactions including hydrogenation [19], aromatization [20], sulfonation [21] and even fluorination [22]. These chemical modifications allow for tuning key performance properties such as proton transport, hydrophilicity, gas permeability, mechanical properties, morphology, thermal stability, crystallinity, and cost.…”

Synthesis and Polymerization of Renewable 1,3‐Cyclohexadiene Using Metathesis, Isomerization, and Cascade Reactions with Late‐metal Catalysts

“…[1][2][3][4][5][6] Much of the interest in polycyclohexadiene (polyCHD) stems from the excellent physical properties that cyclic monomers impart to polymers and the ability to transform polyCHD into conducting polymers and proton conductors. [7,8] Numerous synthetic methods have been reported for the synthesis of 1,3-CHD that utilize dehydrohalogenation, dehydration, and oxidation reactions. In comparison, reduction reactions of benzene usually produce 1,4-cyclohexadiene (1,.…”