Abstract
Effects of incorporation of ionic groups and ionic interactions to a model polypeptide, poly(γ-benzyl-L-glutamate) (PBLG), are studied. Partial conversion of γ-benzyl-L-glutamate residues to glutamic acid residues does not change molecular conformation (α-helix) and shows little change in properties. By contrast, partial conversion to sodium glutamates (ionic groups) leads to conversion from a rigid rod to a semi-flexible rod at low ion contents and causes significant changes in thermal stability and birefringence. In solution, lyotropic liquid crystalline behavior of PBLG is lost at ion content as low as 3.2 mol %. In solid, birefringence is still observed at this ion content, suggesting thermotropic liquid crystallinity of this ionic PBLG. Molecular composites made of ionic PBLG as a reinforcer and poly(4-vinylpyridine) (PVP) as a matrix polymer show significant enhancement in strength and toughness as a result of ion-dipole interactions between the component polymers.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 4890-4898 |
| Number of pages | 9 |
| Journal | Polymer |
| Volume | 55 |
| Issue number | 19 |
| DOIs | |
| State | Published - Sep 15 2014 |
ASJC Scopus subject areas
- Organic Chemistry
- Polymers and Plastics
- Materials Chemistry
Keywords
- Ionic groups
- PBLG
- Thermotropic liquid crystalline