Study On Flame Retardation Of PVA

More and more fire accidents happened in our life in resent years, which caused much damage to people's life. It is reported that among all the people died in fire accidents,90% of them were dead because of the smoke and toxic gases created by polymers in burning. Therefore, developing non-toxic pollution-free flame retardant polymeric materials has become an important subject of scientific development. Poly (vinyl alcohol) is a polyhydroxylated polymer with excellent performance and extensive usage. PVA has been applied widely in fields of fiber, membrane, adhesive and biomedical material with its good compatibility, easy-filmability, fiberizability, cohesiveness and outstanding mechanical property. In this paper, several kinds of flame retardants were used to find the synergistic effect on the flame retardation of PVA films, and PVA composite fiber with great flame retardation was prepared.Phosphorus flame retardant would form a carbon layer in the surface of the material in the process of burning, which will prevent the contact between fire and material. When burning, nitrogenated flme retardant would react to be nitrogen, water vapor and other non-combustible gases, oxygen concentration of the environment could be reduced in this way. Inorganic flame retardant could absorb the heat and release water vapor to the environment so it is of great flame retardant property as well as phosphorus flame retardant and nitrogenated flame retardant. In my research, three kinds of flame retardants were used, FR-106(phosphorus flame retardant from Lianmei Corp.), MA(melamine), LDH(nano hydrotalcite). We added different propotion of flame retardants to discuss the synergistic effect of the flame retardation property of PVA.(1)We found that the addition of phosphorus flame retardant (FR) could improve the flame retardance of PVA, when 20%FR was used alone, we got the highest LOI. If we used more, the flame retardation was worse, that's because there is phase separation in PVA when the propotion of FR is more than 20%.(2)Through the flame retardant synergistic effect, when FR:LDH=40%:8%, we got the best flame retardant material. We know that LDH is insoluble in water, while in our experiment, it could dissolve and dispers uniformly in PVA solution when FR exist. So, both FR and LDH could show their ability of fire retardant, and formed the synergistic effect between each other.(3)The addition of nitrogenated flme retardant (MA) could improve the ability of flame retardation of PVA a little, while go on adding LDH to the PVA solution, we found that the LOI value of PVA films did not change. That's because MA and LDH could not dissolve and disperse in PVA solution uniformly, so neither of them could help to improve flame retardant property.(4) Through the flame retardant synergistic effect, when FR:MA=20%:20%, the flame retardance, mechanical property, thermal property of PVA films were the best. When go on adding LDH to this solution, LOI of PVA films increase to 31 when the amount of LDH was 8%. We can conclude that we got the best synergistic effect in this situation. (5)FR/MA/LDH/PVA composite fiber was prepared by the way of wet spinning, the solution was FR:MA:LDH=20%:20%:8%. The dynamic rheological behavior of PVA composite solution and the process of wet spinning morphology were studied, and also, the structure and properties of PVA composite fiber were studied. We found that PVA composite fiber has better property than PVA fiber, the LOI of the PVA composite fiber was 28.