PREPARATION OF PHOSPHORYLATED CELLULOSE AND EVALUTION OF ITS FLAME RETARDANT AND STRENGTH PROPERTIES

The process of cellulose modification with a mixture of orthophosphoric acid and ammonium polyphosphate or pentasodium triphosphate in a carbamide medium or with the same compounds in presence of magnesium salt was studied. Under these modification conditions, the esterifying composition undergoes direct anionic reorganization with the formation of linear short-chain polyphosphates. It has been established that the level of fire protection of modified cellulose using phosphate formulations depends both on the phosphorus content in the fabric and on the composition of the ester groups introduced. The effectiveness of fire resistance of the obtained materials increases with the length of the phosphate chains. It is shown that in the process of cellulose modifications using impregnated compositions in the range of 130–160 °C cellulose phosphates with small losses in strength of cotton materials (no more than 10–15 %) are produced. The resulting cellulose phosphates have a fire resistance level corresponding to difficult-burning materials.

cellulose, modification, phosphorylating, polyphosphates, ortophosphates, fire-protecting, safety of durability, toxicity

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