Nanocomposite enhanced radiation resistant effects in polyurethane Elastomer with low fraction of polydoapmine nanoparticles

Abstract Polyurethane (PU) is a widely used polymer material, but continuous use in radiation environments make it age rapidly. To improve the service life of PU under irradiation, polydopamine nanoparticles (PDAPs) were used as free radical scavengers to prepare PU/PDAPs nanocomposites by the solution casting method. PU/PDAPs nanocomposites with different PDAPs contents were irradiated by 60Co γ-ray. The cross section of pure PU has obvious cracks after radiation at 200 kGy, whereas almost no cracks were observed after addition of only 1% PDAPs. When added to PU in low amounts (1 wt%), polydopamine caused a dramatic increase (by approximately 50 °C) in its corresponding temperature of maximum decomposition rate. Moreover, DTG curves of PU/PDAPs nanocomposites before and after irradiation was almost the same. These results indicated that polydopamine induced thermal stabilization and radiation resistance on PU. The mechanical properties of PU/PDAPs nanocomposites also have a significant improvement even at 200 kGy radiation. The breaking strength of PU increased from 1.48 MPa (pure PU) to 5.48 MPa (5% PDAPs). The elongation at break of pure PU decreased by about 33.9% after being exposed to 200 kGy irradiation, where the PU added with PDAPs increased by approximately 6.5% (1% PDAPs), 3.7% (2.5% PDAPs) and 19.3% (5% PDAPs). The mechanism of radiation resistance of PU/PDAPs nanocomposites is described. Therefore, PDAPs can be used as an effective anti-irradiation filler to improve the life and stability of polyurethane in radiation environment.