Nucleophilic aromatic substitution (SNAr) reactions are exploited to prepare poly(arylene sulfide)s (PAS's) via the reaction of bis-thiolates and dibrominated pyromellitic diimide (PMDI) derivatives. Small-molecule model studies reveal the reaction is well-defined and proceeds in quantitative yield in practical times at room temperature. Variation in comonomer feed ratios allowed some control over target polymer molecular weights in the step polymerization, but control was likely limited by the relatively poor polymer solubility in the dipolar aprotic solvents typically employed to promote SNAr reactions. One substitution pattern produces a steric “pocket” around the PMDI units, inducing a peculiar solubility trend in halogenated solvents; that is, greatly reduced solubility in CHCl3 relative to CH2Cl2 and C2H2Cl4. One example small-molecule readily dissolves in CHCl3 at room temperature, then rapidly grows poorly soluble crystals revealed by single-crystal XRD to contain CHCl3 molecules in the steric pockets. Finally, the recently demonstrated depolymerization of phthalonitrile-based PAS's via ipso substitution with monothiolates as chain scission agents yields quantitative molecular weight reduction to monomeric species from the polymers reported here.
|Number of pages||6|
|Journal||Journal of Polymer Science|
|State||Published - Jun 15 2022|
Bibliographical noteFunding Information:
This work is the outcome of a Course‐Based Undergraduate Research Experience (CURE). As such this work was funded by student lab fees for the course CHE 533, Advanced Organic Chemistry Laboratory, and by the University of Kentucky, Department of Chemistry. We thank Professors Jack Selegue and Arthur Cammers, both of the University of Kentucky, for helpful discussions.
© 2022 The Authors. Journal of Polymer Science published by Wiley Periodicals LLC.
- nucleophilic aromatic substitution
- poly(arylene sulfide)s
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Polymers and Plastics
- Materials Chemistry