Xue-Rong Fan, Gong Jingjing, Wang Qiang, Zhang Jing (Jiangnan University, Key Laboratory of Ecological Textile, Wuxi 214122) 0 Introduction of oxygen in the bleaching process of cotton fabrics, the hydrogen peroxide decomposition by temperature, pH, and heavy metal ions influence catalysis. Among them, the heavy metal ions, especially Fe3 + on the catalytic decomposition of hydrogen peroxide adept. Fe3 + on the rapid decomposition of hydrogen peroxide is invalid, will cause the fabric of local white, brittle damage, holes, and make cloth yellow, white decreased. Cotton bleaching process Fe3 + mainly from the origin of iron cotton soil, planting the process of iron insecticide spraying, harvesting, processing and packaging with metal abrasion, and bleaching equipment wear and tear.
The author has studied the silica used as the feasibility of oxygen bleaching stabilizer, confirmed its alkaline conditions at high temperature, the decomposition of hydrogen peroxide has strong suppression. The major research project on the silica sol solution containing Fe3 + drift stabilizing effect.
1. I materials, equipment and medicines
14.5/14.5 tex 524/283 roots / 10 cm cotton fabric; breaking strength by the 689 N, latitude 376 N.
Color. Eye 7000A computer detection and matching system (the United States GretagMacbeth), YG (B) D16D-250 Electronic Fabric Strength Tester (Changzhou Second Textile Machinery Factory), Ubbelohde viscometer (Shanghai Chemical Reagent Company) ,76-lA-based Digital temperature glass water bath (Jintan glory Instrument Manufacturing Co., Ltd.).
1.1.3 Drug made sol (solid content 31%, pH value 9), CH3-1 sol (solid content 30%, pH = 10), non-silicon-oxygen bleaching stabilizer 197, HD880 Scouring agents; sodium hydroxide, concentrated ammonia, hydrogen peroxide (30%), potassium permanganate, sulfuric acid, sodium silicate, ferric chloride, calcium carbonate, etc. (all analytically pure).
1.2 sol solution containing Fe3 + drift stability test in different concentrations of Fe3 + solution were added 6 g / L stabilizer, placed in constant temperature water bath, the temperature to 95 ℃, adding 6 g / L hydrogen peroxide (30 %), non-Gab-like handle 60 min, the decomposition rate was measured.
1.3 Cotton fabrics in one bath desizing, scouring and bleaching process
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H2O2 (30%) 10
Scouring Agent 10
Liquor ratio 30:1
Scouring and bleaching process back one bath (95 ℃ × 1 h) → hot water (80 ℃ × 3 times) → warm water (50 ℃ x3 times) → Cold water washing → drying
1.4 Test Methods
1.4.1 H202 decomposition rate was determined by potassium permanganate titration.
1.4.2 whiteness, yellowness of the determination of the Color-Eye 7000A color measurement system measured. To keep each piece of cloth-like warp in the same direction, measured at 4 different locations, records AST-ME313 Hunter whiteness and yellowness values.
1.4.3 Determination of the capillary effect the sample cut 30 cm × 5 cm of the cloth sample hanging bracket, the bottom of the immersion in distilled water, distilled water in 30 min, measured along the height of the fabric rise (cm) .
1.4.4 Determination of fabric breaking strength according to GB / T 3923.1 1 1982 ((tensile properties of fabrics Part l: breaking strength and elongation measured strip method "to determine the breaking strength of treated fabrics .
1.4.5 Determination of fiber polymerization method using copper ammonia solution degree of polymerization of cotton fiber.
2 Results and discussion
2.1 sol of different concentrations of Fe3 + Stabilization of liquid bleach with different Fe3 + concentration in the blank bleach solution, the more silica and sodium silicate on the inhibitory effect of hydrogen peroxide decomposition, shown in Figure 1.
Figure 1 Effect of different stabilizers on the rate of hydrogen peroxide decomposition can see from Figure 1, without stabilizer, the small amount of Fe3 + will accelerate the decomposition of hydrogen peroxide. The higher the concentration of iron ions, hydrogen peroxide decomposition rate of the higher iron concentration 4.5 mg / L, the hydrogen peroxide decomposition rate of nearly 90%. After adding sodium silicate, hydrogen peroxide decomposition rate decreased slightly, but with the Fe3 + concentration increases; adding silica, the hydrogen peroxide decomposition rate of 10% or less, and not with the Fe3 + concentration increases. This shows that the silica sol on the inhibition of Fe3 + in the catalytic ability.
2.2 Sol bleaching solution on the short process Fe3 + inhibited the current, pre-treatment of cotton fabric processing trend is short and efficient process, so starting from the actual production, with cotton fabrics in one bath desizing, scouring and bleaching process, to further study sol on the inhibitory effect of Fe3 + catalyst. Bleaching most practical use of hard water, distilled water and hard water systems, respectively, the study of the Fe3 + catalyzed sol inhibition effect of decomposition of hydrogen peroxide, and compare with other stabilizers.
2.2.1 Comparison of the stability of hydrogen peroxide in distilled water and hard water systems, oxygen bleaching stabilizer on different Fe3 + before and after adding hydrogen peroxide decomposition, such as shown in Table 1 and 2.
Table 1 distilled water system with different oxygen bleaching stabilizer of the decomposition rate of hydrogen peroxide
Note: ① add 10 mg / L FeCl3 (Fe3 +3 mg / L).
Table 2 hard water systems of different oxygen bleaching stabilizer on the decomposition rate of hydrogen peroxide
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Note: ① add 220 mg / L CaCl2 (Ca2 + 80 mg / L); ② adding 80mg / L Ca2 + and 10 mg / L FeCl3.
Know from Table l, in distilled water system, not added Fe3 +, the different stabilizers on the stability of hydrogen peroxide results in order: self-sol> Goods sol> sodium> non-silicon-based oxygen bleaching stabilizer 197. In distilled water add 3 mg / L Fe3 + after, in the absence of stabilizer in the presence of hydrogen peroxide decomposition increased, 15 min after the decomposition rate increased from 67.32% to 90.67% increase. Add the sodium silicate and non-silicon stabilizer 197 after, 60 min after the hydrogen peroxide decomposition rate rose to 90%; to join the home-made silica, hydrogen peroxide decomposition rate rose from 79.62% 83.62% only. This shows that under the conditions of high temperature and alkali, sodium silicate and non-silicon stabilizer 197 can not effectively inhibit the 3 mg / L of Fe3 + on the catalytic decomposition of hydrogen peroxide, which contains hydrogen peroxide decomposition on the inhibition of silica sol is better.
Hard water system (see Table 2), did not add stabilizer decomposition of hydrogen peroxide bleaching solution than the distilled water system, acute, 15 min after the decomposition rate of 82.30%, indicating the decomposition of ca2 + on the hydrogen peroxide has a higher catalytic effect. Non-silicon-based oxygen bleaching stabilizer 197 will not achieve stability in that role under the conditions, because of its hydrogen peroxide decomposition rate than the blank Shihai large. The added silica sol and sodium silicate, its hydrogen peroxide decomposition rate than the slight decrease in Table 1, indicating that ca2 + has a supporting role. In hard water system to join the 3 mg / L of Fe3 + after, 60 min Add a sol, of its hydrogen peroxide decomposition rate and the distilled water system, when the line does not contain Fe3 +, while the rest were increased decomposition. This shows that the cotton fabric in a bath desizing, scouring and bleaching process, ca2 + presence of silica can better inhibit Fe3 + on the catalytic decomposition of hydrogen peroxide.
2.2.2 3,4-fabric bleach and compared the results table system and the hard water in the distilled water system, with different oxygen bleaching stabilizer after the bleaching effect.
Table 3 distilled water system in the different liquid bleach stabilizer effects of drift
Be seen from Table 3,4, adding silica bleaching, the fabric of the indicators are better than using other oxygen bleaching stabilizer, particularly in high fabric strength retention, small fiber damage.
(1) sol solution on the blank drift stability of the role of good Fe3 +, Fe3 + concentration of 7.5 mg / L, the hydrogen peroxide decomposition rate at 10%.
(2) cotton fabric in a bath desizing, scouring and bleaching process, the silica sol on the inhibition of Fe3 + oxygen bleaching stabilizer than other good, hard water, the presence of ca2 +, can inhibit the silica better Fe3 + on the catalytic decomposition of hydrogen peroxide role in the performance of the fabric after bleaching stabilizer treatment is better than other fabrics.
(3) self-inhibition of silica on the Fe3 + slightly better than the merchandise sol.