Reactive dyes have many advantages, such as complete chromatography, bright color, low price and convenient use. They have become the most widely used cotton dyes. However, the wet rubbing fastness of reactive dyes in medium and dark colors is poor, so it is necessary to use color fixing agents to improve the color fastness of cotton fabrics. The traditional fixing agent y and fixing agent M have been banned because they contain free formaldehyde and N-hydroxymethyl in the molecular structure will release formaldehyde. Many literatures have reported the synthesis and application of aldehyde free color fixing agents for reactive dyeing, but most of these color fixing agents use epichlorohydrin, dicyandiamide and diethylenetriamine as raw materials. Epichlorohydrin is highly toxic and does great harm to human body. Its production requirements are very strict in the synthesis process.
DADMAC has good water solubility. It is a quaternary ammonium salt monomer containing unsaturated bond. It is environment-friendly, efficient and non-toxic. Moreover, the cationic monomer can be copolymerized not only in bulk, but also with active monomers with double bond functional groups. Cationic copolymer P (AM-DADMAC) was synthesized by using acrylamide (AM) and DADMAC as raw materials and ammonium persulfate / sodium bisulfite as initiator system in aqueous medium; The effects of monomer mass fraction, monomer mass ratio, reaction temperature, reaction time, initiator mass fraction, initiator and acrylamide feeding mode on the application properties of copolymer P (AM-DMDAAC) were discussed. The results show that the synthesized P (AM-DADMAC) has good color fixing performance for cotton fabric and no formaldehyde emission. It can be used as a safe, environmental friendly and efficient aldehyde free color fixing agent for cotton.
Conclusion
(1) Binary polymer P (AM-DADMAC) was synthesized by copolymerization of acrylamide (AM) and dimethyl diallyl ammonium chloride (DADMAC) in aqueous medium with EDTA as chelating agent and (NH4) 2S2O8 / NaHSO3 initiator system. The optimum synthesis process was as follows: monomer mass fraction 40%, m (AM): m (dm-daac) = 1:5, reaction temperature 60 ℃, reaction time 6 h, initiator mass fraction 1%. The feeding mode of initiator solution and acrylamide aqueous solution was continuous dropping.
(2) The synthesized copolymer P (AM-DADMAC) can be used as a color fixing agent for reactive dye cotton fabric. The dyed fabric has grade 3 wet rubbing fastness, grade 4 dry rubbing fastness and grade 4 anti staining fastness.
