polydimethylsiloxane modification of segmented thermoplastic polyurethanes and polyureas
In addition, the syntheses of primary and secondary aminoalkyl functional PDMS based segmented polyureas are described herein. Two-phase morphology was observed for all the polyurea samples, even when the hard segment concentration was as low as 6wt%. All these polyureas formed clear transparent films that exhibited good mechanical properties even with very high PDMS content, up to 94wt%. They also demonstrated similar thermal stability, independent of the PDMS end group. However, the nature of the end group, i.e. primary or secondary aminoalkyl, had a dramatic effect on mechanical and morphological properties of these PDMS based polyureas, which was interpreted in terms of the level of hydrogen bonding.
- Doctoral Dissertations