Abstract:

In order to improve the dyeing effect of wool fabric using acid dye under neutral condition, chitosan(CS) of three different molecular weights (100 000, 50 000 and 10 000) was used to synthesize N,N,N-trimethyl chitosan(TMC) by formaldehyde-formic acid method. Then it was reacted with cyanuric chloride to prepare the final product O-monochlorotrazinyl-N,N,N-trimethyl chitosan (MCT-TMC). FT-IR was used to characterized the products. The dyeing effects of wool fabric by acid dye were discussed by changing the molecular weight and consumption of the chitosan derivatives. The results show that the dye effect of wool fabric treated by MCT-TMC are far better than by TMC. The molecular weight of chitosan derivatives is positively related to the dyeing rate, fixation rate, K/S value, color fastness and antimicrobial activity of wool fabrics, but it has little effect on fabric strength. When the raw material molecular wight of MCT-TMC is 100 000 and its consumption is 2% (o.w.f), the modified wool fabric has optimum performance. The dyeing rate is 95.5%, the fixation rate is 91.7%, the K/S value of it is 12.2, and the inhibition rates against E.coli and S.aureus are 82.4% and 84.2%, respectively.

Key words: chitosan, quaternary ammonium salt, wool, acid dye, dyeing improvement