An Investigation On Environmentally Friendly Flame Retardant Finishing Of Nylon6,6Fabric

Nylon6,6fabric have been widely used in many areas of our lifebecause of its excellent properties and good wearing characteristics.However, it also has many indispensable shortcomings especially itsinflammability. It is easy to form melting dripping during the burningprocess which can cause fire hazard. Therefore, it is very imporatant toimprove the flame retardancy of nylon6,6fabric.In this study, a flame retardant system containing SFR2011and urea isapplied to PA66fabric. The influence of the mass ratio of SFR2011andurea, the flame retardant concentration, and technological conditions oncombustion performance of nylon6,6fabric was investigated. The optimalprocess is as follows: the mass ratio of SFR2011and urea is1:3, the flameretardant concentration is30%, and curing temperature is160℃. Thetreated nylon6,6fabric has good resistance to melt drop with a LOI valueof up to35.0%, damaged length of4.2cm, after-flame time of only1.04sand minimal loss of mechanical properties. Thermo-gravimetric analysis(TGA and DTA) indicates that the initial degradation temperature offinished nylon6,6fabric is lower than that of the untreated sample. Thedecomposition rate decreases and carbon residue increases duringcombustion after treatment. SEM graphs of residue of treated and untreatednylon-6,6fabric show that the cross-section of residue of the nylon-6,6fabric has a honeycomb-like intumescent structure. It is suggested thissystem can improve the flame retardancy of PA66fabric by the interaction of gas phase flame retarding，endothermic flame retarding and condensedphase flame retarding.Furthermore, keeping the best ratio of SFR2011and urea，pentaerythritol(PER) was added to this flame retardant system. The effectof PER content on the flame retardancy of nylon6,6fabric was studied.The results shows that LOI value can reach up to37.4%for the sampletreated with a solution having the optimal SFR2011/urea/PER mass ratio of1:3:1.5. The treated sample has damaged length of3.5cm. After-flame timeand melt dripping have not been observed in vertical burning tests. It isproposed that the addition of PER can improve the flame retardancy ofnylon6,6fabric.Chemical initiator-induced grafting with acrylamide as monomer anddibenzoyl peroxide (BPO) as initiator has been used to improve the flameretardancy of nylon6,6fabric. The effects of reaction time, reactiontemperature and monomer concentration on the percentage of grafting (PG)were investigated. The effect of percentage of grafting (PG) on the fireperformance of AM-g-nylon6,6fabric was also studied. The flameretardancy, thermal behavior and chemical structure were characterized byLOI, UL94test, cone calorimetry, TGA, DTA and ATR-FTIR. The resultshows the after-fame time and char length have been reduced to3.01s and4.9cm after grafting. Mechanical property and microstructure ofAM-g-nylon6,6fabric were also analyzed by electronic tensile machineand SEM respectively.