Waste nitrile rubber powders enabling tougher 3D printing photosensitive resin composite

UV-curing 3D printing has shown extensive applications, but its crucial photosensitive resin is still challenged by poor toughness and high brittleness . This study is to improve the toughness of 3D printing resin by modified waste nitrile rubber powders (WNRP). Component analysis of WNRP indicates that volatile compounds , rubber polymers and inorganic fillers are 11, 44 and 43 wt%, respectively. The thiol contents grafted on WNRP range from 18 to 58 μmol/g via thiol-ene reaction. The incorporation of modified WNRP into 3D printing photosensitive resin slightly improves viscosity and decreases conversion, but it still can be printed out high-precision items. A little of modified WNRP significantly improves the toughness from 1.9 to 3.4 kJ/cm 2 by 80%, depending on cavitation and deformation effect. This strategy not only greatly improve the toughness of 3D printing resin, but also reutilize waste rubber powders enabling to decrease resource waste.