Construction Of Bio-based Flame Retardant System And Their Influences On The Combustion And Durability Of Nylon/Cotton Blend Fabric

Nylon/Cotton(NYCO)blend fabrics have outstanding advantages over both nylon and cotton fibers,combining the comfortability and air permeability of cotton and the high strength and abrasion resistance of nylon.However,both nylon and cotton fibers are very flammable.The NYCO blend fabrics are easy to ignite because of the“scaffold effect”,which causes greater fire hazards and seriously affects the safety of people’s lives and property,limiting its application in many fields including the home textile,military uniform,transportation seats.It is of great significance to investigate the environmentally durable flame retardant NYCO blend fabrics in order to satisfy the high demand and flame retardant requirements for NYCO blend fabrics in many fields.In this thesis,three different bio-based phosphorus-containing flame retardant systems were selected to prepare flame retardant durable NYCO blend fabrics,and both the flame retardancy and washing durability of the treated fabrics were improved.The main research work of the paper as following:(1)Phytic acid(PA)and taurine(Tau)were used to prepare the fully bio-based flame retardant PA-Tau through the ion-exchange reaction in the aqueous phase.The flame retardant NYCO blend fabrics were fabricated by the dip-roll-dry process.The limiting oxygen index(LOI)value of the treated fabrics was increased from 18.5%to 42.9%,and the damaged length was decreased from 30.0 cm to 5.9 cm in the vertical burning test.The peak of heat release rate(p HRR)value of the PA-Tau-NYCO fabrics was reduced from 305k W/m~2to 111 k W/m~2during the cone calorimeter test(CCT).The char formation ability of the PA-Tau-NYCO fabrics was enhanced and increased to38.0 wt%at 800~oC.The flame retardant mechanism analysis indicated that the flame retardant performance of PA-Tau-NYCO fabrics was effectively improved by forming the char layer in the condensed phase and diluting oxygen and combustible gases in the gas phase.The fully bio-based flame retardant could be used in NYCO blend fabrics in a green and safe way.(2)3-glycidyloxypropyl trimethoxy silane(GPTMS)associated with polyethyleneimine(PEI)and PA was incorporated on NYCO fabrics by covalent bonds through facile sol-gel and dip-nip-dry method to prepare flame retardant blend NYCO fabrics with enhanced 20 laundering cycles(LCs)washing durability.The LOI value of treated fabrics was increased from18.5%to 29.8%and the damaged length was reduced from 30 cm to 7.5 cm.CCT indicated that the p HRR value was reduced from 195 k W/m~2to 53k W/m~2and total heat release(THR)value was decreased from 12.3 MJ/m~2to2.5 MJ/m~2respectively.The flame retardancy of the G-PEI/PA-NYCO fabrics was well maintained and showed self-extinguishing behavior after 20 LCs.The char residue of the G-PEI/PA-NYCO fabrics was reinforced from 9.9 wt%to 39.1 wt%and the possible flame retardant mechanism was proposed.The synergistic effect of P-N-Si elements further promoted the flame retardant system.Moreover,dermal irritation test showed good biological safety of the G-PEI/PA-NYCO fabrics,which was incapable to cause erythema and edema on rabbit skin.(3)The novel bio-based flame retardant ammonium salt of taurine phosphonate(PTau)was successfully synthesized from taurine and grafted onto the NYCO blend fabrics by P-O-C covalent bonds.Both the flame retardancy and 40 LCs washing durability of the PTau-NYCO fabrics were improved significantly.The LOI value of the PTau-NYCO fabrics was improved from 18.5%to 36.7%and the damaged length was reduced to 5.6cm.The flame retardancy of PTau-NYCO fabrics was well preserved with the LOI value of 29.2%after 40 LCs.CCT indicated that the PTau-NYCO fabrics reduced the p HRR value from 218 k W/m~2to 79 k W/m~2and the THR value from 10.1 MJ/m~2to 2.6 MJ/m~2respectively,compared with that of the control NYCO blend fabric.Thermogravimetric analysis test showed that the char formation ability was improved for PTau-NYCO fabrics with the char residue of 37.2 wt%at 800~oC.The flame retardant mechanism showed that PTau is beneficial to form the char layer and generate nonflammable gases.The synergistic effect of P-N-S elements further facilitated the flame retardancy.In general,this work proposed a feasible method to produce durable flame retardant NYCO blend fabrics by using bio-based taurine derivatives.