The Synthesis And Application Of Flame Retardant Containing Phosphite Ester For Polyester

Phosphorus and nitrogen elements could be used as an environmentally friendly flame-retardant element because their products are less toxic and generate less smoking. Flame retardants containing phosphorus and nitrogen are usually called intumescent flame retardants. It could provide polymers with better flame retardancy than those composed of one element.The Mannich Reaction of phosphite esters is an important organic reaction with mild conditions and low cost, so it has a wide use in both basic research and commercial utilization. This article is mainly based on the Mannich Reaction in order to synthesize a perdurable flame retardants containing phosphorus and nitrogen.First of all, different series of amine, aldehyde, ester were chosen to synthesize flame retardant, according to the physical performance of the compound and the flame resist performance of the fiber that been finished by the compound, the proper reactant were chosen. Secondly, the influencing factors of the synthesis process were optimized and the optimal procedure of production was determined based on the performances as follow: the physical nature of the flame retardants which were tested by the appearance of the shape, color, viscosity and particle size; The molecular structure of synthesized compounds which were identified by means of infrared and elementary analysis; The flame resist performances of the fibers which were evaluated by vertical combustion method and oxygen index method. On this basis, the study of application of those flame retardants were done, the polyester fabric was choiced in using an ordinary baking rolling finishing, the factors of the amount of flame retardants, baking temperature, pH value were tested in turn, ultimatly, the best finishing process was determined.Besides, the compatibility between two flame retardant FR-K FR-2 and two kinds of fluorinated water-repellent agents were discussed based on the one-bath finishing to polyester fabric. Experiment result shows that the flame retardant FR-2 have the better compatibility with fluorinated water-repellent agents, the fabric which is finished by the one-bath finishing process shows no significant drop in the flame resist performance and waterproof performance. The flame retardant FR-1 doesn’t have the same compatibility with fluorinated water-repellent agents as FR-2. The one-bath finishing process shows great impact to the fabric on flame resist performance but a smaller on waterproof performance.The polyester fabrics which been finished by the FRs were investigated by TGA-DTG and SEM. The TGA-DTG results show that the FRs decreased the initiate decomposition temperature of polyester fabric but enhanced its char residue at high temperature. SEM investigations revealed that the polyester treated by FRs respectively formed the continuous and close outer surface of the char layer during combustion, which acted as a good barrier to the transfer of heat and combustible gas between the flame zone and the substrate, and thus protected the underlying materials from further burning.