Zhang Wenbo, Zhao Zhenhe, Zhang Peng (School of Textiles and Materials, Xi'an Polytechnic University, Xi'an 710048, China)
Abstract: A silicone oil modified soap-free vinegar-acrylic emulsion was prepared by semi-continuous seed emulsion polymerization using vinyl acetate and acrylate monomers, vinyl silicone oil and a small amount of polymerizable emulsifier. The infrared spectrum and laser particle size analyzer were used. The product was characterized. The silicone oil modified vinegar-acrylic emulsion is used as a binder for dyeing cotton fabric coatings. The optimized process is: silicone oil modified vinegar emulsion 5%, coating 0. 5%, plus crosslinker 0. 5%; pre-bake at 80 °C for 3 min, and bake at 150 °C for 3 min. The results show that the dry and wet rubbing fastness and soap fastness of the dyed fabrics with silicone oil modified soap-free vinegar-acrylic emulsion as binder are equivalent to those of traditional adhesives, and the hand feel is soft.
Key words: silicone modification; vinegar-acrylic emulsion; soap-free; adhesive; paint dyeing; cotton fabric CLC number: TS193. 64 Document code: A Article ID: 1000 - 4017( 2013) 01 - 0009 - 04
0 · Introduction Traditional emulsion polymerization requires the addition of an emulsifier to convert mutually incompatible oils and water into emulsions that are difficult to delaminate. However, emulsifiers affect the electrical properties, optical properties, surface properties and water resistance of emulsion polymers [1]. These defects can be effectively improved by using a small amount of a polymerizable emulsifier to bond to the polymer macromolecular chain. Polyvinyl acetate-acrylate emulsion (acetoacetate emulsion) is a widely used adhesive in recent years. Compared with pure acrylic and styrene-acrylic emulsions, it has the characteristics of low price and not easy to yellow [2], but the vinegar-acrylic emulsion film has the same disadvantages as the pure acrylic film. The introduction of vinyl silicone oil into the vinegar-acrylic emulsion for graft modification can significantly improve the water resistance and hot-adhesive cold-brittleness of the film [3], thereby improving the hand-feel of dyed fabrics [4].
1· Test 1. 1 Main raw materials and equipment Fabric: Plain woven cotton (14 57 tex)
Drugs: vinyl acetate (VAC), butyl acrylate (BA), acrylic acid (AA), hydroxyethyl acrylate (HEA), potassium persulfate (KPS, Wuxi Weir Chemical Co., Ltd.), anion-non-reactive surface activity Agent (laboratory), vinyl silicone oil (Hubei Zaoyang Sihai Chemical Co., Ltd.), paint blush FGR, sodium alginate, plus crosslinker (commercially available)
Instrument: JJ-1 electric agitator (Shanghai Pudong Physical Optics Instrument Factory), H. H. S 11-28 Electric thermostatic water bath (Shanghai Medical Equipment Factory No. 5), DHG- 9076A type electric temperature controlled blast drying oven (Beijing Kewei Yongxing Instrument), BP221S electronic balance (Germany Sartorius), LA- 205 type fabric heat setting machine (Japan Co., Ltd.), Y57N rubbing fastness tester (Nantong Hongda), SW-12A wash fastness tester (Wuxi Textile Instrument Factory), LS-900 laser particle size analyzer (China Europe and America) Instrument Co., Ltd.), FT-IR-5700 Infrared Spectrometer (Nicolet Instruments, USA)
1. 2 Synthesis of silicone oil modified vinegar-free soap-free emulsion First, put some water and polymerizable emulsifier into a three-necked flask, and then add vinyl acetate, acrylate monomer, vinyl silicone oil and some initiator solution in a certain order. Maintain the stirring speed of 800 r / min, pre-emulsification for 30 ~ 60 min; remove 4 /5 of the pre-emulsion; add the remaining initiator solution to the remaining 1 / 5 pre-emulsion, and place in a constant temperature water bath The temperature is raised to 70 °C in 10 min at a stirring speed of 250 to 400 r /min, and the emulsion starts to bloom blue. At this time, the temperature rises rapidly, and cooling water is required to control the temperature. After the temperature is stabilized, the remaining 4 /5 pre-emulsified is added dropwise. Liquid, drip 3. After 5 h, the temperature was raised to 85 °C and kept for 2 h. After cooling, ammonia was added to adjust the pH to neutral, and the material was filtered.
1. 3 Emulsion performance test and characterization (1) Determination of solid content of emulsion Weigh 1 ~ 2 g emulsion sample, bake to constant weight, calculate solid content S according to formula (1):
Where: M0———the quality of the dry weighing bottle, g
M1—Quality of mass bottles and emulsions, g
M2——Quality of mass bottle and dried emulsion, g
(2) Determination of conversion rate During the reaction, take 1 ~ 2 g of emulsion at regular intervals, weigh and record the exact mass G0; then add 2 to 3 drops of freshly prepared hydroquinone solution (5%). It is placed in an oven at 110 ~ 120 °C and dried to constant weight G1. The conversion rate Y is calculated according to formula (2):
Where: G0———sample quality, g
G1—the quality of the sample after drying, which is M2 - M0,g
A———The total mass of the material, g
B———non-volatiles (emulsifiers and initiators) in the feed, quality, g
C———the total mass of the monomer, g
(3) Polymerization stability The polymerization stability is represented by a gel fraction. After the completion of the polymerization reaction, the cooled emulsion was filtered through a 200 mesh nylon mesh, and the agglomerates on the filter, the three-necked flask and the stirrer were collected, washed with water and dried at 100 to 120 ° C until constant weight, and then weighed and counted as W1 after cooling. Calculate the percentage of gel content as a percentage of the total monomer charge according to formula (3):
Among them, W1—the quality of the aggregate after drying, gW2—the total mass of the monomer, g
(4) Particle size distribution The emulsion was diluted by a certain factor, and the particle size and distribution of the emulsion were measured at room temperature using an LS-900 laser particle size analyzer. (5) Fourier transform infrared spectroscopy A small amount of soap-free emulsion was uniformly applied to a clean glass slide, baked in an oven, and then measured by a FT-IR-5700 Fourier transform infrared spectrometer.
1. 4 paint dyeing 1. 4. 1 paint dyeing formula /%
Paint blush FGR 0. 5
Adhesive 5
Crosslinking agent 2 ~ 0. 5
Add water to 100
1. 4. 2 Process and conditions Fabric padding dyeing solution (room temperature, two dip two rolling, 80% residual rate) → drying (80 °C, 3 min) → baking (150 °C, 3 min)
1. 4. 3 Fabric performance test (1) Apparent color depth The apparent color depth K/S value of the dyed fabric was determined by the thinking computer colorimeter. The fabric is folded into 4 layers, three points per piece, and averaged.
(2) Color fastness to rubbing According to GB/T 3920-1997 "Color fastness to rubbing of textile color fastness test" and GB / T 6151-1997 "General rules for test of textile color fastness".
(3) Color fastness to soaping According to GB / T 3921. 1-1997 "Determination of color fastness to textiles - Test 1".
(4) Softness The dyed fabric feel is manually determined by at least 5 professionals, and the softness is evaluated and averaged. Softness is divided into five levels: level 1 (hard), level 2 (harder), level 3 (general), level 4 (softer), level 5 (soft). If the average is not an integer, round to the nearest 0. Level 5, and is indicated by "~", such as 3 to 4.
2 · Results and discussion 2. 1 The effect of the amount of vinyl silicone oil on the emulsion polymerization A two-layer method was used to prepare a silicone oil-modified vinegar-free soap-free emulsion. Change the amount of vinyl silicone oil to explore its effect on the silicone modified vinegar emulsion and fabric dyeing properties, as shown in Table 1.
It can be seen from Table 1 that as the content of silicone increases, the blue color of the emulsion gradually increases, the conversion rate increases, and the gelation rate decreases, indicating that the vinyl silicone oil can increase the emulsion polymerization rate. The main reason may be that the vinyl silicone oil has a larger molecular mass than the acrylate monomer, and each polymerized vinyl silicone oil monomer molecule is equivalent to polymerizing with a plurality of acrylate monomer molecules, and its unique double-end double bonds are easy to open. It can be polymerized with other acrylate monomers. However, when the amount of silicone oil is more than 8%, the conversion rate starts to decrease. The main reason is that vinyl silicone oil introduces a hydrophobic Si—O—Si group into the emulsion acrylate macromolecular chain, resulting in a decrease in hydrophilicity of the emulsion, an increase in gel fraction, and insufficient monomer reaction. The dyeing of the modified emulsion with different amounts of vinyl silicone oil did not change the K / S value of the fabric. For the sake of comprehensive consideration, the optimum amount of vinyl silicone oil is determined to be 8% (for the quality of acrylic monomers, the same below).
2. 2 Silicone-propylene modified vinegar-free soap-free emulsion performance test and characterization 2. 2. 1 Comprehensive performance Acetate-acrylic emulsion polymerization was carried out according to the above process conditions, and the comprehensive properties of the obtained emulsion are shown in Table 2. It can be seen from Table 2 that the prepared silicone oil modified soap-free vinegar-acrylic emulsion has good performance, fine emulsion and blue light, and has good centrifugal stability and dilution stability.
2. 2. 2 Particle size distribution The particle size distribution of silicone oil modified vinegar emulsion is shown in Figure 1.
It can be seen from Fig. 1 that the particle size of the silicone oil modified vinegar emulsion is mainly distributed at 0. 1 ~ 5. 0 μm, and concentrated in 1. About 80 μm. The particle size is a unimodal distribution with a relatively complete normal distribution.
2. 2. 3 Infrared characterization The film of silicone oil modified vinegar-free soap-free emulsion was analyzed by Fourier transform infrared spectroscopy (FT-IR). The results are shown in Fig. 2.
As can be seen from Figure 2, 2 961. The antisymmetric and symmetric stretching vibration absorption peaks, in-plane and out-of-plane bending vibration absorption peaks of C-H bonds on methyl and methylene groups appeared at 7 cm - 1,1 438 cm -1 and 1 372 cm -1; 1 735. 0 cm - 1 is the asymmetric stretching vibration absorption peak of the carbonyl C O bond; 1 235. 4 cm - 1 and 1 170. 7 cm - 1 is the asymmetric and symmetric stretching vibration absorption peak of C-O-C in the ester group. 1 021. 8 cm - 1 is the skeleton stretching vibration absorption peak of Si-O bond, 800. The asymmetric stretching vibration absorption peak of Si-CH3 bond exists near 3 cm -1 , indicating that the vinyl silicone oil has undergone chemical crosslinking reaction with the polymer molecular chain rather than simple physical mixing.
2. 3 Silicone-modified acrylate adhesive coating dyeing process The self-made vinegar-free soap-free emulsion was applied to the dyeing of cotton fabrics, and the effects of various dyeing process conditions on the properties of dyed fabrics were investigated.
2. 3. 1 Effect of baking time The baking can make the effective functional groups in the adhesive react through the relevant groups of itself or the fabric, and generate the network cross-linking by covalent bond, which greatly improves the color fastness or other properties of the dyeing.
It can be seen from Table 3 that when the baking time is more than 3 min, the rubbing color fastness and the soaping fastness of the cotton fabric are good, indicating that the adhesive has already produced a mesh film on the surface of the fabric. Continue to extend the baking time, the K / S value does not change significantly. Considering that prolonged baking time increases energy consumption and exacerbates fabric damage, it is determined that the preferred baking time is 4 min.
2. 3. 2 Effect of baking temperature The effect of baking temperature on the color fastness and softness of the fabric is shown in Table 4.
It can be seen from Table 4 that as the baking temperature increases, the rubbing fastness and soaping fastness of the fabric gradually increase; but when the temperature is too high, the fabric has a yellowing phenomenon, and the hand feel is deteriorated, and the softness is lowered. When the baking temperature is 150 °C, the color fastness of the fabric has reached the requirement. Therefore, a preferred baking temperature of 150 °C was selected.
2. 3. 3 Comparison of dyeing properties of different adhesives Compared with the coating effect of self-made silicone-acrylic soap-free emulsion adhesive and traditional industrial adhesive (with small molecular emulsifier), see Table 5.
It can be seen from Table 5 that the self-made silicone-acrylic soap-free emulsion is used for coating dyeing, and the rubbing fastness and soaping fastness of the fabric are not inferior to the traditional industrial adhesive, and the softness is better.
2. 3. 4 The effect of external crosslinking agent Silicone soap-free emulsion is used for coating dyeing, adding 0 ~ 0. The color fastness of the dyed fabric was tested with 6% cross-linking agent. The results are shown in Table 6.
It can be seen from Table 6 that as the amount of the crosslinking agent used increases, the rubbing fastness and the soaping fastness of the fabric are improved, but at the same time, the hand feel is gradually deteriorated. Therefore, the crosslinking agent is preferably used in an amount of 5 g / L.
3 · Conclusions (1) The self-made silicone modified vinegar-free soap-free emulsion has good performance and high stability. Copolymerization occurred between the monomers as determined by FT-IR and laser particle size analyzer analysis.
(2) Applying silicone-modified vinegar-free soap-free emulsion as a binder to cotton fabric coating dyeing, can give the fabric a softer hand, and the dry and wet rubbing fastness and soaping fastness of the dyed fabric are combined with traditional bonding. The agent is equivalent. î—…î—…î—…
references:
[1] Cao Tongyu, Liu Qingpu, Hu Jinsheng. Principle and application of polymer emulsion synthesis principle [M]. Beijing: Chemical Industry Press, 2007.
[2] Sun Fuxia. Study on emulsion polymerization of acrylic modified polyvinyl acetate [J]. Colloids and Polymers, 2008, 26(4): 15-18.
[3] Long Bin, Huang Chunbao, Wang Hainan, et al. Preparation of silicon/acrylic composite emulsion and its application progress [J]. Journal of Textiles, 2006, 27 (3): 9-11.
[4] Niu Song, Zhao Zhenhe, Li Xiaopeng, et al. Synthesis and application of silicone-free soap-free emulsion [J]. Printing and Dyeing, 2010, 36(6) : 9.
With Bluetooth Retractable Ceiling Fan
Hidden Blade Ceiling Fan,Fandelier Retractable Blades,Ceiling Light With Retractable Fan,Crystal Retractable Ceiling Fan
JIANGMEN ESCLIGHTING TECHNOLOGY LIMITED , https://www.windfansummer.com