Physicochemical Characterization of Two Polysulfon‐Amides in Dilute Solution

Abstract

AbstractSummary: As one class of high temperature resistant aromatic polymers, polysulfonamides (PSA) are widely used in industry, physicochemical properties and conformation in solution have not been disclosed yet. In this work, the dilute solution behaviour of poly(m‐diphenylsulphone terephthal amide) (m‐PSA) was investigated by laser light scattering (LLS) and viscometry. The results showed that the m‐PSA exists as single chains both in dimethylsulfoxide (DMSO) and dimethylformamide (DMF). The value of radius of gyration to hydrodynamic radius (s/Rh) indicats that the m‐PSA has a random coil conformation in solution. Both the persistence length a and the characteristic ratio C∞ indicate that the m‐PSA chain is flexible in solution. The Mark‐Houwink equation of m‐PSA in DMSO was determined as [η] = 1.62 × 10−5M, and the exponent of 0.87 supports the assumption that m‐PSA forms random coils in DMSO‐solution at 25 °C. It was found that the flexibility of the PSA was affected when 4,4'‐diphenylsulphone terephthalamide monomer was incorporated in backbone. The PSA random copolymer (r‐PSA) with a comonomer ratio of 3:1 (4,4′‐diaminodiphenyl‐ sulfone to 3,3′‐diaminodiphenylsulfone) also had a random coil conformation in DMF; the rigidity increased, while the mobility of the chain was maintained.