ABSTRACT: Click chemistry has been used to prepare a range of novel polymers with pendant carboxylic acid side groups. Four azido carboxylic acids, either mono- or difunctional and aliphatic or aromatic, have been prepared and thoroughly characterized. Extensive model reactions with 1-ethyl-4-hydroxybenzene, the simplest model for poly(4-hydroxystyrene), and the four azido carboxylic acids have been conucted to establish the proper reaction conditions and provide an analytical frame for the corresponding polymers. Poly(4-hydroxystyrene) moieties in three different polymers—poly (4-hydroxystyrene), poly(4-hydroxystyrene-co-methyl methacrylate), and poly(4-hydroxy- styrene-b-styrene)-----have been quantitatively transformed into oxypropynes by the use of either Williamson nr Mitsunobu strategies and subsequently reacted with the azido carboxylic acids. Detailed differential scanning calorimetry investigations of ali the polymers in general exhibit [when poly(4-hydroxystyrene) is a subetantial parti significant changes in the glass-transition temperature from the polar poly(4-hydroxystyr- ene) (120—130 “C) to the much less polar alkyne polymers (46—60 DC). A direct correlation between the nature of the pendant groups in the derivatized polymers and the glass-transition temperature has emerged: the aromatic carboxylic acids give high glass-transition temperatures (90—120 DC), and the aliphatic carboxylic acids give lower glass-transition temperatures (50—65 DC).
|Journal||Journal of Polymer Science|
|Publication status||Published - 2006|
- Click Chemistry
- Carboxylic Acids
- Block Copolymers
- Glass Transition
- Functionalization of Polymers