✍ Scribed by Hergenrother, P. M.
No coin nor oath required. For personal study only.
Hydroxy‐terminated polysulfones (PSs) of number‐average molecular weights from 3000 to 26,000 g/mol were converted to the corresponding 4‐ethynylbenzoate–terminated PS through a three‐step synthesis. The initial step involved the reaction of the hydroxy precursor with 4‐bromobenzoyl chloride followed by displacement of the bromo group with trimethylsilylacetylene using a palladium catalyst. The trimethylsilyl group was subsequently cleaved with a weak base to afford the ethynylbenzoate‐terminated PS. A more direct route to the ethynylbenzoate‐terminated PS involved the reaction of the hydroxy‐terminated PS with 4‐ethynylbenzoyl chloride. The trimethylsilylethynyl and ethynyl groups undergo a thermally induced reaction to provide modified PS with better solvent resistance and higher apparent glass transition temperatures than an unmodified linear PS. The physical properties of the modified PS are compared with those of a linear PS.
📜 SIMILAR VOLUMES
## Abstract Polysulfone has been carboxylated, via a metalated intermediate, by reaction of a THF solution of polymer with __n__‐butyllithium and then treatment with carbon dioxide. The polymer reactions with __n__‐butyllithium were close to quantitative and did not require the use of a tertiary am
This study concerns the synthesis of anhydride terminated oligoimides (ANTOI) and allyl terminated oligoimides (ALTOI), in acetic acid medium, which allows a very fast reaction and an easy working out. For the preparation of ALTOIs, two methods are compared: the first one consists of adding the mono