Journal of Polymer Science Part A: Polymer Chemistry, Vol.40, No.12, 2049-2054, 2002
Star-shaped and photocrosslinked poly(1,5-dioxepan-2-one): Synthesis and characterization
New star-shaped and photocrosslinked poly(1,5-dioxepan-2-one) (PDXO) has been synthesized through ring-opening polymerization initiated by SnOct(2)/pentaerythritol. The star-shaped PDXO was end-functionalized by acrolyol chloride to form acrylate end groups. The end-functionalized PDXO was photocrosslinked initiated by 2,2-dimethoxy-2-phenylacetophenone. The gel content ranged from 80 to 99%, indicating a high degree of crosslinking. The thermal properties of the star-shaped PDXO and the photocrosslinked PDXO were analyzed by differential scanning calorimetry. The glass-transition temperature was determined to approximately -32 degreesC for the crosslinked PDXO. The viscosity numbers were determined for star-shaped PDXO, with reference to linear homologues. The star-shaped PDXO had lower viscosity numbers than the linear counterparts, The crosslinked PDXO showed a rather hydrophilic surface as compared with other resorbable polyesters. The advancing contact angle was 64 +/- 2, and the receding angle was 57 +/-4.
Keywords:crosslinking;elastomers;hydrophilic polymers;photopolymerization;poly(1,5-dioxepane-2-one);ring-opening polymerization