Cyclic ketene acetal esters derived from acetylsalicylic acid with various substituents on their aromatic rings were investigated. Substitution by two tert-butyl groups improved the stability of the monomer against moisture. Furthermore, the polymer solubility was increased by the flexible substituents, and the glass transition temperature was significantly increased owing to restricted bond rotation. The bulkiness of the tert-butyl group reduces the monomer reactivity, resulting in an almost ideal alternating copolymer with dimethyl maleate.
- Yasuhiro Kohsaka
- Hanae Torisawa
- Akane Kazama
