Effect of antioxidant/light stabilizer on properties of 3D printed photochromic wood-plastic composites

Functional photochromic wood-plastic composites (PWPC) have great application potential in interior decoration and other fields. However, the lifespan of PWPC is usually short. In this paper, antioxidant 1010 and light stabilizer 770 were introduced into PWPC to improve the mechanical properties and photofatigue-resist of composites. The wood flour/polylactic acid (WF/PLA) based photochromic composites were prepared via melt blending and printed by fusion deposition technology (FDM). The mechanical properties, interfacial compatibility, thermal stability, and photofatigue-resist of WF/PLA composite were then characterized. The results show that when antioxidant 1010 is added alone, compared with WF/PLA composite, the tensile, flexural and impact strength of composite increased by 42.58%, 23.25% and 6.52%, respectively. However, adding light stabilizer 770 alone, the tensile and flexural strength increase while the impact strength decreases. When antioxidant 1010 and light stabilizer 770 are added to WF/PLA composite at mass ratio of 1∶1, the tensile strength of composite increased by 1.8% under the synergistic effect of these two additives, the bending and impact strength decreased by 9.3% and 22.1%, respectively. Compared with other combinational systems, the decrease in mechanical properties is the lowest. In addition, WF/PLA composite with mass ratio antioxidant 1010 to light stabilizer 770 of 1∶1 has better thermal degradation properties and photofatigue-resist than WF/PLA composite. The temperature at mass loss of 5% is 219.84℃. On the 10th day of aging, the surface color difference ΔE of WF/PLA composite increased from 5.3 to 6.7, increase of 26.7%.