Enhanced mechanical performance of cellulose nanocrystal doped eco-friendly calcium-alginate based bio-composite fiber with superior flame retardancy

Petroleum-based polymer fire-resistant fabric is not considered as eco-friendly, and has other problems like heavy weight and irritating tickling. On the other hand, even though Ca-alginate fiber is a natural fire-resistant polysaccharide derivative, its low tensile strength prevents the fiber from being a potential fire-resistant material. To enhance its mechanical performance, cellulose nanocrystal (CNC) functioned as reinforced nanofiller, assisted by a small amount of propanol to improve CNC dispersion in solution. CNC-doped alginate fiber (pC-Alg) was fabricated by the microfluidic spinning technique, and the effects of CNC content and the drawing ratio on the fibrous mechanical performance were investigated. Comparative studies indicated that a combination of 0.50 wt.% CNC, 6.00 v.% propanol, and 1.6 draft ratio helped pC-Alg fiber to achieve outstanding breaking strength of around 2.00 cN/dtex. It was shown that the use of propanol solvent and the incorporation of CNC can effectively eliminate CNC aggregation and reach a three-fold better tensile performance than the control. Limiting oxygen index test also showed that the resultant hybrid pC-Alg fiber still displayed good flame retardancy, making it an ideal candidate for fire-protection clothing.

Automated summary

Petroleum-based polymer fire-resistant fabric is not eco-friendly and heavy, while Ca-alginate fiber has low tensile strength. By adding cellulose nanocrystal and propanol to improve CNC dispersion, pC-Alg fiber with excellent mechanical performance and flame retardancy was fabricated.