| Autor: |
in 't Veld, P.J.A., Wei-Ping, Ye, Klap, Richard, Dijkstra, Pieter J., Feijen, Jan |
| Přispěvatelé: |
Faculty of Science and Technology, Biomaterials Science and Technology |
| Jazyk: |
angličtina |
| Rok vydání: |
1992 |
| Předmět: |
|
| Zdroj: |
Makromolekulare Chemie, 193(8), 1927-1942. Wiley-VCH Verlag |
| ISSN: |
0025-116X |
| Popis: |
Novel biodegradable poly(ester-amide)s were prepared by ring-opening copolymerization of -caprolactone and 3- and/or 6-alkyl-substituted morpholine-2,5-dione derivatives. The copolymerizations were carried out in the bulk using stannous octoate as an initiator. Molecular weights of the copolymers ranged from 1,0 · 104 to 8,3 · 104 and decreased with increasing mole fractions of morpholine-2,5-dione derivatives in the feed. 13C NMR sequence analysis indicated that the copolymers had a random distribution of -oxycaproyl and depsipeptide units, which resulted from the occurrence of transesterification reactions during copolymerization. The results of the DSC measurements and 13C NMR sequence analysis showed a close relationship between the crystallinity and average length of ε-oxycaproyl blocks. Copolymers with a mole fraction of depsipeptide units smaller than 0,20 were semi-crystalline, whereas incorporation of larger amounts of depsipeptide units resulted in amorphous copolymers. The melting point depression as a function of the molar composition of the semi-crystalline copolymers was in good agreement with the melting point depression predicted by the Baur equation, which indicated the rejection of depsipeptide units from crystals consisting of ε-oxycaproyl units. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
|
Plný text