| Recently, fires caused by the textiles burned is increasing. It makes people’s lives and properties to face a serious challenge and threat. Because of the excellent breathable moisture absorption, the cotton fabric is widely used in daily life. However, the cotton fiber is very flammable, it is extremely urgent to research the cotton flame retardants.Currently, the most popular cotton flame retardants in the market are THPC and Pyrovatex CP. Both flame retardance are good. However, they all have high levels of formaldehyde on the fabric. Therefore, the development of new cotton flame retardant with no formaldehyde is a important issue.In this thesis, the new reactive flame retardants are synthesized by Mannich reaction of dimethyl phosphate. It makes sure that no formaldehyde release in the process of using and synthesis. And the same time, According to the synthetic principle of flame retardant HP, changing the synthesis methods and conditions can synthesize a new flame retardant. The last, we study its flame resistance and filter out the best finishing process.In the second chapter, we prepared two kinds of small molecule flame retardants by using dimethyl phosphate reacting with different kinds of aldehyde and amine and test the flammability and durability of flame retardants. Moreover, using the phosphorous compound A reacting with phosphorus pentoxide and ethylene oxide to monitor the reaction process, finally we found the flame retardant that we synthesized have obvious flammability and durability.In the third chapter, the new flame retardant’s cross-linking agent and catalyst would be studied. In order to filter out the best finishing process, we do the single factor experiments on flame retardant concentration, cross-linking agent concentration, catalyst concentration, catalyst proportion, curing temperature and curing time, and find the best single factor experimental conditions. On this basis, four factors and three levels orthogonal experiment was carried out for finding the final finishing process. For the same time, cotton fabric durability, the free formaldehyde content of the fabric, the tensile strength at break and discoloration would be observed after finishing by flame retardant. In the final, TGA-DTG and SEM were applied in the study of flame-retardant properties.The last chapter summarizes the experimental result. There are three flame retardants being synthetized, and two kinds of flame retardants are small molecules, they have obvious flame retardance, However, they have no durability. And the new oligomeric phosphate flame retardant has obvious flame retardance and durability. Meanwhile, in the choice of DM-3507and85%phosphoric acid+magnesium,respectively as cross-linking agent and catalyst. After finishing experiment to confirm that the best finishing condition is flame retardant concentration of400g/L, the cross-linking concentration of100g/L, the catalyst concentration of25g/L(1:1.5), curing temperature of170℃and the curing time of4min. Under the optimal finishing conditions, the fabric’s damage length can still less than the national standard B1level after washing50times. Meantime, it has little effect on the fabric’s discoloration and mechanical properties. After adding formaldehyde catcher, formaldehyde content of fabric less than75ppm. |
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