Structure and properties of nanosilica reinforced biodegradable polyester elastomers

Silica/poly(sebacate-glycerol-citrate) nanocomposites, in which nanosilica content varied from 0 phr to 20 phr, were prepared by in-situ polymerization and surface modification. The influence of nanosilica contents on the structure and properties was studied. The composites with different silica contents exhibited excellent comprehensive properties relative to unfilled elastomers. The tensile strength improved from 0.9 MPa to 5.3 MPa. SEM and TEM photos showed that the nanosilica dispersed as nano-scale network in the matrix, and the modified nanosilica exhibited good interfacial bonding with the matrix. XRD measurement was applied to investigate the changes in structure on a short-range molecular level, which suggested that the existence of nanosilica limited the formation of ordered structure. The DSC curves demonstrated that the glass transitions of the composites inclined moving toward a lower temperature as the nanosilica content increased. Results of the in vitro degradation test suggested that nanosilica content could adjust the degradation speed of the composites.