3D Printing Itaconic Acid/Hydroxypropyl Cellulose Hydrogels and Its Flame Retardancy
Hydrogel flame retardant materials based on natural polymer macromolecules are increasingly becoming a focus of scientific research due to their outstanding flame retardancy and environmental compatibility.In this study,modified itaconic acid(EP)and modified hydroxypropyl cellulose(HPCS)were used as the initial precursors to fabricate a kind of natural polymer hydrogel(EP/HPCS hydrogel)with excellent thermal stability and flame retardancy through the visible light-curable 3D printing technology.The results demonstrate that the hydrogel shows excellent water retention properties and could retain a high moisture content even after a long time of air exposure.Thermogravimetric analysis reveals that the EP/HPCS hydrogel possesses good high-temperature thermal stability,with a char residue of up to 3.445%.This hydrogel exhibits excellent flame retardancy,with a limiting oxygen index(LOI)value of 63.3%.The vertical combustion test shows that this hydrogel also has self-extinguishing properties.Furthermore,the tensile strength of the hydrogel could reach 113.34 kPa.This hydrogel material combines high-temperature thermal stability,good mechanical properties,and flame retardancy,providing a new approach for the green development of a new generation of halogen-free flame retardant materials that are applied in the fields such as fabric thermal protection and coal mine safety.