| Lyocell/cotton blended fabrics have the advantages including low shrinkage,less hairiness,excellent breathability,moisture absorption,and drape performance,and thus welcomed by the majority of consumers.The application scope of this fabric in the textile industry is gradually expanding.Unfortunately,lyocell/cotton blended fabric is extremely flammable,and there is a potential threat to people’s lives and property safety.Consequently,the flame retardancy of lyocell/cotton blended fabrics needs to be improved urgently,and how to improve the flame retardancy of lyocell/cotton blended fabrics has become a serious and challenging issue.In the first part,creatinol phosphate(COP)was directly used as the flame retardant,and the treated lyocell/cotton blended fabric possessed excellent flame retardant properties through the pad-dry-cure process.FTIR,SEM,EDS and XPS analyses proved that COP was successfully grafted onto the surface of the blended fabric and distributed evenly.Compared with the control fabric,the char residue rate of the flame-retardant fabric at 800℃ increased by 229%(air atmosphere),indicating that it has excellent char-forming ability.The cone calorimetry test showed that the total heat release(THR)of the modified sample was reduced by 12.8 MJ/m~2,and the flame retardancy of the blended fabric was significantly improved.The results proved that COP is an effective intumescent flame retardant,which can be used for flame retardant finishing of lyocell/cotton blended fabric.This work provides a new strategy for the preparation of flame-retardant blended fabrics.In the second part,N,N’-carbonyldiimidazole(CDI)was selected as the crosslinking agent,and the flame retardant 2-carboxy ethylphenyl hypophosphorous acid(CEPPA)was directly used for the flame retardant finishing of lyocell/cotton blended fabric.FTIR,XPS,EDS and SEM analyses proved that the flame retardant elements P and N were successfully grafted onto the lyocell/cotton blended fabric and distributed uniformly.TG test showed that the residual char residue of flame-retardant fabric in air atmosphere increased by 195%.Both the vertical burn test and the LOI test demonstrate the fabric’s excellent flame and wash resistance.The LOI value of the treated lyocell/cotton blended fabrics reached 27.2%,which only dropped by 2.57%after 270 minutes of washing.This work provides a new method for preparing durable flame-retardant fabrics. |
