Short methylene segment crosslinks in degradable aliphatic polyanhydride: Network formation, characterization, and degradation

✍ Scribed by Ann-Christine Albertsson; Maria Eklund

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 904 KB
• Volume: 34
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(199606)34:8<1395::aid-pola2>3.0.co;2-#

✦ Synopsis

SYNOPSIS

Crosslinked poly(adipic anhydride) has been obtained in this study of the synthesis of a rapidly hydrolyzable crosslinked polymer system. The thermal, mechanical, and degradative behavior was markedly affected by the ratio of reactants, using 0-50 mol % of the crosslinking agent. Optimum properties were reached a t 20-30 mol %. Methylene segment crosslinks were obtained by copolymerizing oxepan-2,7-dione (adipic anhydride) with 1,2,7,8-diepoxyoctane. The crosslinking reaction resulted in polyester bonds but the material had a significant amount of poly(adipic anhydride) homosequences. These are crucial for a rapid degradation. The network formation is dependent on the functionality of the reactants, on the reactivities of the functional groups and on the reaction pathways. In this study, the most important factor affecting the structure of main chains is the higher reactivity of the anhydride compared to that of the epoxide leading to homopolymer sequences. This was also evident in the model reaction between oxepan-2,7-dione and 1,2-epoxybutane. The initial degradation profile of the crosslinked polymer corresponds to the linear counterpart of the polymer. The remaining polyester network has a longer degradation rate. 0 1996