| For increasing the durability of durable press finished cotton fabrics, optimization of durable press finishing process, different swelling agents, fibrous strength protective agent R-CD, moisture curing process and highly active mixed catalyst system were investigated so as to improve strength loss without reduce crease recovery angles of treated cotton fabrics in this dissertation.Different kinds of cross-linking agents, catalysts, softeners and curing temperature, curing time all affected the properties of durable press finished cotton fabrics, so firstly, this dissertation optimized the durable press finishing process. Among different cross-linking agents, F-ECO was confirmed to be better, and formaldehyde release of fabric treated with F-ECO was only 52ppm. Through the investigation of concentration of cross-linking agent F-ECO and magnesium chloride, curing temperature and curing time, the suitable applied process was established. The results showed that concentration of F-ECO was the most influencing factor on crease recovery angle, the suitable concentration of F-ECO was 100g/l, and curing temperature was the most influencing factor on strength loss, 150℃was suitable. In addition, experiments indicated that adding softener could improve crease recovery angles and tearing strength retentions, but could reduce breaking strength retention to some extent. Silligen SIE was confirmed to be better than other softener. After 20g/l Silligen SIE was added in the finishing solution, tearing strength retention was increased about 30%, and breaking strength retention was not affected too much.SPSS mathematic analytical software was used to analyze the relation among cross-linking agent, curing temperature, crease recovery angle and strength. The results again showed that concentration of cross-linking agent was the most influencing factor on crease recovery angle, and curing temperature was the most influencing factor on strength loss. The equation of curing temperature and strength showed that strength loss was not only caused by cross-linking but also caused by acid degradation. Experiments also indicated that cross-linking occurred fully for modified 2D resin when curing temperature was at 140-160℃, and strength loss was caused almost from cross-linking. When curing temperature was beyond 160℃, strength loss was caused from acid degrading. Moreover, value of E indicated that strength could be improved through reducing curing temperature tol40-150℃.Different metal salt catalysts were compared in this paper, the results indicated that magnesium chloride was the best suitable. But it needed 150℃×2-3min, at which cross-linking could occur fully. Combing magnesium chloride with different organic acids as a new catalytic system was also investigated in order to increase catalytic activities, so the curing temperature could be lowered or curing time could be shortened, and the strength loss could be reduced. Experimental results showed that glycolic acid was the best effective as a synergist with magnesium chloride. When 19g/l magnesium chloride and 1g/l glycolic acid were used as a catalyst, crease recovery angle of treated cotton was 286.7°, warp and weft breaking strength retentions of treated fabrics are 66.6% and 65.1% respectively. In addition, curing temperature could be lowed or curing time could be shortened due to higher catalytic reactivity combining magnesium chloride with glycolic acid. When the cotton fabric was curing at 140℃×2min, compared with magnesium chloride as a catalyst alone curing at 160℃×2min, crease recovery angle was increased 18°, warp and weft breaking strength retentions were increased 3.8% and 9.9% respectively. When the cotton fabric was curing at 160℃×1min, compared with magnesium chloride as a catalyst alone curing at 160℃×2min, crease recovery angle was increased 20°, warp and weft breaking strength retentions were increased 4.1% and 7.1% respectively.Adding suitable swelling agent could improve the properties of durable press finished fabrics, so this paper studied different swelling agents such as urea, thiourea, triethanolamine, glycol, diethylene glycol, glycerol and polyethylene glycol (PEG) in the durable press finishing. The results showed that thiourea and triethanolamine were not suitable to be used in the durable press finishing because they reduce crease recovery rapidly. Adding urea, glycol, diethylene glycol and glycerol all improve strength retention, but crease recovery angles were lowered a little. Among all swelling agents, polyethylene glycol was proved to be the best. Adding polyethylene glycol (PEG) not only increased crease recovery angles but also reduced strength loss. Different molecular of PEG was studied, PEG600 was confirmed to be the best. In the F-ECO finishing solution, after adding 150g/l PEG600, crease recovery angle was increased 20°, tearing strength retention was increased from 60.7% and 89.3%, breaking strength retention was increased from 51.1% and 57.5%, DP rating was increased 0.5. After adding 150g/l PEG600 in the citric acid (CA) finishing solution, crease recovery angle was increased 30°, breaking and tearing strength retention were increased 2.4% and 14.7% respectively. After adding 150g/l PEG600 in the 1,2,3,4-butanetetracarboxylic acid (BTCA) finishing solution, crease recovery angle was increased about 25°, breaking and tearing strength retention were increased 8.5% and 14% respectively. Adding PEG600 also increased K/S values of dyed fabrics, improved softness and abrasion of finished fabrics. Moreover, adding PEG600 could reduce curing temperature. After adding 150g/l in the F-ECO finishing solution, curing temperature could be reduced from 150℃to 130℃. Crease recovery angles of treated fabrics curing at 130℃with PEG600 were a litter higher than that of treated fabrics without PEG600 when curing at 150℃, but breaking strength retention was increased from 51.4% to 72.7%, and tearing strength retention was increased from 60.7% to 94.8%. In the same time, after adding 150g/l in the BTCA finishing solution, curing temperature could be reduced from 180℃to 170℃, and breaking strength tearing retention were increased 24.7% and 17.9% respectively. After adding 150g/l in the CA finishing solution, curing temperature could be reduced from 180℃to 160℃, and breaking strength tearing retention were increased 37.5% and 24.9% respectively.Monochlorotriazinyl-β-cyclodextrin (R-CD) was investigated in the durable press finishing. Although R-CD contained many reactive groups, it was not a good cross-linking agent, crease recovery angle was much lower than that of modified 2D resin and CA. However, after adding R-CD in the F-ECO finishing solution, strength loss could be reduced. Different concentration of R-CD and F-ECO, curing temperature and time were studied. The experimental results showed that cotton fabric treated with 20g/l R-CD and 100g/l F-ECO, curing at 150°C×2min, the strength retentions were improved obviously. Compared with strength retentions of treated without R-CD, warp and weft strength retentions were increased 17.7% and 17% respectively, and warp and weft strength retentions were increased 15.7% and 43.2%, respectively. Adding R-CD had only a little effect on crease recovery angle.Finally, moisture cross-linking process was investigated. The cotton fabric was in swollen state when moisture cross-linking occurred, and effective factors on the properties of moisture cross-linking treated fabric were concentration of F-ECO and hydrochloric acid, deposited time, water containing ratio of treated fabric after drying. So different effected factors mentioned above were studied, and suitable applied conditions were as follows: concentration of F-ECO was 200g/l, concentration of hydrochloric acid was 30mmol/l, deposited time was 24 hours, water containing ratio of treated fabric after drying was 6-8%. At the above condition, although dry crease recovery angle of treated fabric was a litter lower than that of treated fabric with traditional finishing process, however, wet crease recovery angle was increased about 20°, and warp and weft breaking strength retentions were increased 21.8% and 33.5% compared with traditional finishing process. DP rating of treated fabric was also increased 0.3. Electronic scan of treated fabrics indicated that the amorphous region of moisture cross-linking treated fabric was sealed less than that of traditional process treated fabric, this could be certified by higher K/S of dyed fabric and moisture regain than that of treated fabric with traditional finishing process.
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