Lyocell／二硫代焦磷酸酯阻燃纤维的制备及其阻燃机理研究

Preparation and flame retardant mechanism of Lyocell/bisneophentyl glycol dithiopyrophosphate flame-retardant fiber

将阻燃剂二硫代焦磷酸酯(DDPS)超细粉体与纤维素/N-甲基吗啉-N-氧化物(NMMO)溶液共混后,通过干湿法纺丝制备了阻燃Lyocell,并对阻燃Lyocell的阻燃性能、分解产物、成炭过程以及阻燃机理进行了研究。结果表明:随着DDPS添加量的增加,Lyocell分解温度有所降低,但残炭量有所提高;阻燃Lyocell的极限氧指数(LOI)随着DDPS添加量的增加呈现正相关;当DDPS质量分数为25%时,阻燃Lyocell的LOI可以达约26%,热释放速率降低50%;DDPS在高温下会促进生成石墨化程度高的致密炭层,DDPS对Lyocell的阻燃主要呈现出凝聚相阻燃机理。

A flame-retardant Lyocell was prepared by blending bisneophentyl glycol dithiopyrophosphate （ DDPS） flame retard-ant ultrafine powder and cellulose /N-methyl morpholine-N-oxide （ NMMO） solution via dry wet spinning process .The flame retardance , decomposed products , char formation and flame-retardant mechanism of the flame-retardant Lyocell were studied . The results showed that the decomposition temperature of Lyocell was decreased and the quantity of char residue were increased in some degree with the addition of DDPS;the limiting oxygen index （ LOI） showed a positive correlation with the amount of DDPS;the LOI of the flame-retardant Lyocell reached about 26%and the heat release rate reduced by 50%as the mass fraction of DDPS was 25%;DDPS promoted the formation of compacted char residue with high graphitization degree and offered the condensed phase flame retardant strategy .