Synthesis And Application Of Flame-retardant For Nylon Fabric

Nylon is one of the most used polymers for synthetic fibers, and nylon production ranks the second place in the synthetic fiber. Comparison with other fibers, nylon fiber has many advantages, such as good abrasion resistance, high elastic resilience, high breaking strength,excellent dyeing properties, the specific gravity small and no worm, etc. But thermal performance of nylon is poor, the ignitability and molten droplets in the combustion process of nylon easily make fire to spread, which is very unfavorable for fire-fighting. In a word, the drawbacks of nylon seriously limited the extensive application. But so far,flame-retardants used in finishing are few on the market. Aiming at these problems, two kinds of flame-retardants are studies, one was a crosslinked sulfur-containing phosphoric amide flame-retardant. Another was an eutectic amide-containing flame-retardant. And they were used in flame retardant finishing on nylon fabric, contents and results of study are as follows:Using the anhydrous aluminum chloride as the catalyst, the phosphate monoester(PHME)was synthesized by polyphosphoric acid(PPA) and epoxy chloropropane(EC). Using DCC as the condensing agent, the sulfur-containing phosphoric amide flame-retardant(FRS) was synthesized by PHME and thiourea(TU). The structures and properties were studied by FTIR,1HNMR and TG-DTA. The optimal synthetic conditions of PHME were as follows:n(PPA) : n(EC) = 1.5:1, catalyst was was 2%, the temperature was 80℃ and the reaction time was 3h. The optimal synthetic conditions of FRS were as follows: n(PHME) : n(TU)= 1:1.1, catalyst was was 1.5%, the temperature was 110℃and the reaction time was 2h.With the water-soluble isocyanate-terminated as cross-linker, the flame retardant was applied to flame retardant finishing on nylon fabric. Finally, the test indicated that the LOI value and damaged carbon length of the finished nylon fabric were 34.1% and 5.7 cm,respectively, when the concentration value of FRS and WIT were 200 g/L and 40 g/L,respectively, and the baking temperature and time were 150℃ and 3 min, respectively.After 10 laundry cycles, the LOI value and damaged carbon length of the finished nylon fabric were 28.5% and 7.7 cm. The test indicated that the FRS has good durable flame retardancy.Using the ethanol as the solvent, the PA66 was synthesized by adipic acid(AA) and hexamethylene diamine(HAD). Using DCC as the condensing agent, the FR was synthesized by pentoxide and thiourea(TU). The eutectic amide-containing flame-retardant(PA-FR) was synthesized by PA66 and FR. The structures and properties were studied by FTIR,1HNMR and TG-DTA. The optimal synthetic conditions of PA-FR were as follows: m(FR) : m(PA66) = 2.5 : 1, catalyst was was 2%, the temperature was110℃ and the reaction time was 3.5h. Finally, the test indicated that the LOI value and damaged carbon length of the finished nylon fabric were 30.4% and 7.1 cm, respectively,when the concentration value and p H of PA-FR were 200 g/L and 7, respectively, and the baking temperature and time were 150℃ and 3 min, respectively. After 10 laundry cycles,the LOI value and damaged carbon length of the finished nylon fabric were 26.8% and 9.4cm. The test indicated that the PA-FR has some durable flame retardancy.