Preparation of flame retardant waterborne polyurethane and its coating for polyester fabric
Waterborne polyurethane(PU)was modified with flame-retardant polyester polyol as a phosphorus source,and the properties of the resultant modified waterborne PU emulsion,film,and coated polyester fabric were character-ized.The results indicated that the flame-retardant polyester polyol as a modifier was completely participated in the flame-retardant modification of waterborne PU.When the phosphorus content was less than 5 wt%,the flame-retardant water borne PU emulsion presented an aspect from translucent to milky white,its particle size was less than 100 nm,and its centrifugal stability was good.The waterborne PU film exhibited a decrease in the water absorption rate,mechanical properties and cracking temperature with an increase in the phosphorus content,but its mass retention rate increased.The coated polyester fabric reached a nonflammable level at a phosphorus content of 3 wt%.The mechanism analysis in-dicates that it was feasible to finish polyester fabric with the flame-retardant waterborne PU coating.