Preparation and property on seawater-degradable Fe3O4@PVA/PLGA composite films

Fe3O4@PVA microcapsule catalyst with dissolution as trigger condition was synthesized by utilizing nano Fe3O4 catalyst as core material and water-soluble polyvinyl alcohol as shell material. The microcapsule catalyst was loaded in poly(lactic-co-glycolic acid)(PLGA) membrane to prepare the freshwater/seawater degradable Fe3O4@PVA/PLGA composite films.Transmission electron microscopy (TEM) and dynamic light scattering (DLS) particle size distribution were used to test the morphology of Fe3O4@PVA. The shell thickness of Fe3O4@PVA core-shell particles is 2-3 nm. The structural characteristics, magnetic and mechanical properties of Fe3O4@PVA core-shell particles and Fe3O4@PVA/PLGA composite membrane were determined by FTIR, XPS, TG, VSM and electronic universal material tests. The degradation properties of Fe3O4@PVA/PLGA composite films in freshwater, seawater, air, darkness and low temperature environments were discussed. The results show that the maximum degradation ratio of Fe3O4@PVA/PLGA composite films is 97.79% at 120 days in seawater and 99.75% at 120 days in freshwater. Fe3O4@PVA/PLGA composite films are degraded in the seawater and the mass average molecular weight decreases from 28440 to 1396.