Cotton Coated with Polyurethane and Microencapsulated Flame Retardants: An Analysis of Flame Behavior

The combination of polyurethane (PU) and phosphates is recognized for forming effective flame retardant (FR) intumescent systems. However, the flame retardant properties can be compromised due to the water solubility of phosphates, making the intumescent coating non-permanent. To address this issue, microencapsulation techniques were employed, encapsulating di-ammonium hydrogen phosphate (DAHP) within a polyurethane shell. The chemical and physical structures of the DAHP microcapsules were characterized to assess their stability and performance. Cotton fabrics were coated with polyurethane formulations containing either neat DAHP or encapsulated DAHP. Results demonstrated that microencapsulation of DAHP within a polyurethane shell significantly enhanced the flame retardant performance of the coated cotton. © The authors.