In Situ Generating CaCO3 Nanoparticles Reinforced Nonflammable Calcium Alginate Biocomposite Fiber

Petroleum-based synthetic flame-proof fiber releases toxic volatile organic compounds in thermal decomposition process and has other problems, like tickling feeling and high density. A natural polysaccharide, calcium alginate, is an intrinsic fire-resistant biodegradable material, but its limited mechanical performance prevents it from being a practical flame-retardant fabric. To address this problem, Na2CO3 was doped into alginate spinning solution to obtain in situ generating CaCO3 nanoparticle-reinforced alginate fiber by microfluidic spinning technique. Comparative analysis illustrated that incorporation of 0.50% Na2CO3 into the fiber greatly improved its mechanical performance; meanwhile, in situ generated CaCO3 nanoparticles also throttled oxygen and heat flow in burning, endowing the fiber with excellent flame retardancy. The prepared composite fiber released less heat, smoke, and toxic volatile organic compounds in burning, which reduced the fire hazard. The formed residue char and pyrolysis products functioned as the physical barrier and displayed a synergistic effect to inhibit oxygen and heat transmission and impede the further combustion. All of the results demonstrate that the obtained fiber exhibits a good mechanical and flame-retardant performance, making it an ideal candidate as a fire-protection textile.

Automated summary

By incorporating Na2CO3 into alginate spinning solution, CaCO3 nanoparticles can be generated in situ to greatly improve the mechanical performance of the fiber. This fiber has excellent flame retardancy with reduced heat, smoke, and toxic volatile organic compound emissions during burning.