摘 要:為提升分散染料染色錦綸的色牢度,在偶氮染料分子中引入二氯均三嗪結(jié)構(gòu)作為活性基團(tuán),并采用三聚氯氰與N-乙基-N-羥乙基苯胺的縮合以及進(jìn)一步與芳胺重氮鹽的偶合等兩步反應(yīng),設(shè)計(jì)合成出7支偶氮型活性分散染料。采用印花方式將所得活性分散染料對(duì)錦綸織物進(jìn)行染色,測(cè)試染色錦綸織物的色深、固色率、色牢度、熱遷移和斷裂強(qiáng)力等性能。結(jié)果表明:染色錦綸織物具有良好的得色率、鮮艷性和勻染效果,同時(shí)具有良好的耐有機(jī)溶劑萃取性能。染色錦綸的固色率達(dá)到74%~90%,耐皂洗、耐摩擦和耐升華色牢度可達(dá)4級(jí)及以上,顏色遷移率不超過(guò)5%,顯現(xiàn)出優(yōu)異的顏色堅(jiān)牢程度。該研究結(jié)果可為研發(fā)具有高色牢度特性的錦綸染色用活性分散染料提供參考。
關(guān)鍵詞:活性分散染料;錦綸;染色;固色率;色牢度
中圖分類號(hào):TS193.2;TQ613.1
文獻(xiàn)標(biāo)志碼:A
文章編號(hào):1009-265X(2024)07-0097-11
錦綸,俗名為尼龍,是中國(guó)化纖行業(yè)中產(chǎn)量?jī)H次于滌綸的第二大化學(xué)纖維[1]。2022年,中國(guó)錦綸總產(chǎn)量為410萬(wàn)噸。目前,市場(chǎng)上產(chǎn)量最多的錦綸品種是錦綸6和錦綸66,它們分別以己內(nèi)酰胺或己二酸、己二胺為單體通過(guò)聚合反應(yīng)并紡絲制得[2]。錦綸具有質(zhì)量輕、熱穩(wěn)定性好、力學(xué)性能好、強(qiáng)度高、彈性大等特性,廣泛應(yīng)用于制作運(yùn)動(dòng)服、絲襪、傳送帶、帳篷、工業(yè)用布等[3]。錦綸在染淺色時(shí)可采用弱酸性、活性或分散等類型染料進(jìn)行染色[4-6],這些染料上染率高,染出的織物勻染性好、色牢度高,然而在染深濃顏色時(shí),常出現(xiàn)色牢度下降的問(wèn)題[7-8]。
近年來(lái),開(kāi)發(fā)活性分散染料并用于纖維染色成為染料領(lǐng)域的一個(gè)研究熱點(diǎn)?;钚苑稚⑷玖吓c錦綸具有良好的親和力,染料可進(jìn)一步通過(guò)活性基與錦綸以共價(jià)鍵結(jié)合。因此,采用活性分散染料染色是提升染色錦綸色牢度的一種有效手段?;钚苑稚⑷玖贤ǔJ窃谑杷园l(fā)色體上連接活性基團(tuán)來(lái)構(gòu)造。常見(jiàn)的發(fā)色體類型有偶氮[9]、蒽醌[10]和雜環(huán)[11]等結(jié)構(gòu),而活性基類型則有均三嗪和乙烯砜等。目前,將均三嗪與偶氮結(jié)構(gòu)結(jié)合是設(shè)計(jì)活性分散染料最主要的方式[12]。該設(shè)計(jì)思路簡(jiǎn)潔有效且染料合成方便。但是,已報(bào)道的分子設(shè)計(jì)通常將三嗪結(jié)構(gòu)和偶氮結(jié)構(gòu)上的伯氨基直接進(jìn)行結(jié)合,使得偶氮發(fā)色體電子效應(yīng)深受影響,從而進(jìn)一步影響染料色光。
由于活性分散染料不溶于水,采用水相染色法時(shí)需先對(duì)染料進(jìn)行研磨分散處理[13],從而殘留大量有色廢水。目前,報(bào)道最多的活性分散染料應(yīng)用方法是采用超臨界二氧化碳染色法[14-16]。采用該法時(shí),染料溶解性好,上染率高,未染色的染料還可回收。但該法所需的高溫高壓條件使其受染色設(shè)備限制而不利于大規(guī)模推廣。Jeong等[17]提出熱轉(zhuǎn)移印花方式對(duì)錦綸織物進(jìn)行著色。雖然該方法不產(chǎn)生廢水,但需要預(yù)先將染料溶解在有機(jī)溶劑中,而且高達(dá)190~210 ℃的熱轉(zhuǎn)移印花溫度對(duì)染料的耐熱性提出了高要求。
本文將三嗪結(jié)構(gòu)接枝到偶氮苯發(fā)色體的羥乙基上,旨在利用烷基的阻隔作用來(lái)降低活性基團(tuán)對(duì)發(fā)色體的影響,采用接枝縮合和偶合等兩步反應(yīng)合成得到7支染料,并進(jìn)一步采用水相印花方式對(duì)錦綸進(jìn)行染色,同時(shí)測(cè)試染色錦綸織物的色深、固色率、色牢度、遷移性和斷裂強(qiáng)力等性能,并探討染料結(jié)構(gòu)與染色性能之間的構(gòu)效關(guān)系。本文染料合成簡(jiǎn)單、成本低廉,印花操作簡(jiǎn)便,可為開(kāi)發(fā)高性能活性分散染料提供有益參考。
1 實(shí)驗(yàn)
1.1 材料及儀器
實(shí)驗(yàn)材料:錦綸6(100%,針織,230 g/m2);N-乙基-N-羥乙基苯胺、三聚氯氰、苯胺、對(duì)氯苯胺、對(duì)硝基苯胺、2,6-二氯-4-硝基苯胺、2-氨基-5-硝基苯甲腈、2-氨基-3-氯-5-硝基苯甲腈和2-氨基-5-硝基噻唑,均為分析純,購(gòu)于上海麥克林試劑有限公司;N, N-二甲基甲酰胺(DMF)、1,5-萘二磺酸、亞硝酸叔丁酯、丙酮、碳酸氫鈉、尿素、碳酸鈉、硫酸鈉、石油醚和乙酸乙酯,均為分析純,購(gòu)于杭州高晶精細(xì)化工有限公司;海藻酸鈉(99%),購(gòu)于杭州天馬思宏數(shù)碼科技有限公司;分散藍(lán)SE-3RT,購(gòu)于浙江龍盛染料化工有限公司。
實(shí)驗(yàn)儀器:AVANCE AV400 MHz核磁共振波譜儀(瑞士布魯克公司);NlcoletiS50型傅里葉變換紅外光譜儀(美國(guó)賽默飛公司);LCQ-FLEET型質(zhì)譜儀(美國(guó)賽默飛公司);UV-2600型紫外分光光度儀(日本島津公司);TGA熱重分析儀(Mettler Toledo 公司);MINI MDF/767型磁棒印花機(jī)(溫州大榮紡織儀器有限公司);SF-600型計(jì)算機(jī)測(cè)色配色儀(美國(guó)Data Color公司);SW-24 A II型耐洗色牢度試驗(yàn)機(jī)(溫州大榮紡織儀器有限公司);萬(wàn)能型紡織品耐磨試驗(yàn)機(jī)(溫州大榮紡織儀器有限公司);YG(B)605D型耐熨燙升華牢度試驗(yàn)儀(溫州大榮紡織儀器有限公司);YG611 M型日曬氣候色牢度儀(溫州方圓儀器有限公司)。
1.2 化合物的合成方法
室溫下,在250 mL三口燒瓶中依次加入三聚氯氰(50 mmol,9.22 g)、碳酸氫鈉(50 mmol,4.20 g)和N-乙基-N-羥乙基苯胺(50 mmol,8.25 g),最后加入75 mL丙酮,室溫?cái)嚢?6 h。經(jīng)薄層色譜監(jiān)測(cè),N-乙基-N-羥乙基苯胺消耗完全后,反應(yīng)液加入去離子水(100 mL)和乙酸乙酯進(jìn)行萃取。有機(jī)相再使用飽和食鹽水洗滌,無(wú)水硫酸鈉干燥后,在減壓條件下除去有機(jī)溶劑,得到粗產(chǎn)物,經(jīng)硅膠柱層析(洗脫劑:V石油醚/V乙酸乙酯 = 4/1)分離得到中間體,產(chǎn)量12.8 g,收率為82%[18]。1H NMR(CDCl3,400MHz)δ 7.29(d,J=7.6 Hz,2H),6.77(dd,J=16.7,7.8 Hz,3H),4.68(t,J=6.2 Hz,2H),3.78(t,J=6.2 Hz,2H),3.50(q,J=6.9 Hz,2H),1.23(t,J=7.0 Hz,3H)。13C NMR(CDCl3,100 MHz)δ172.62,171.03,146.94,129.57,117.02,112.43,67.29,48.72,45.90,12.27。ESI-HRMS(m/z,C13H14Cl2N4O)計(jì)算值:313.0500([M+H]),實(shí)測(cè)值:313.0606。IR(KBr)ν=2970,1600,1525,1360,1294,1178,1024,848,742 cm-1。
1.3 重氮鹽的制備方法
方法一:在室溫下,將苯胺(5 mmol)緩慢加入反應(yīng)瓶中,加入2 mL水,然后向瓶中加入2 mL鹽酸,攪拌10 min。稱取亞硝酸鈉(5 mmol)溶于2 mL水中,將亞硝酸鈉水溶液在0~5 ℃時(shí),加入到反應(yīng)瓶中,反應(yīng)1 h,得到苯胺重氮鹽溶液。該方法還適用于對(duì)氯苯胺重氮鹽的制備[19]。
方法二:將2,6-二氯-4-硝基苯胺(5 mmol)和1,5-萘二磺酸(5 mmol)溶解在溫度為50 ℃的乙酸乙酯(50 mL)中,攪拌10 min后,在25 ℃、2 min內(nèi)滴入亞硝酸叔丁酯(7.5 mmol),進(jìn)一步攪拌20 min,溫度維持在25 ℃,然后將析出的固體產(chǎn)物抽濾,風(fēng)干,得到2,6-二氯-4-硝基苯胺固體重氮鹽。該方法還適用于對(duì)硝基苯胺固體重氮鹽和2-氨基-5-硝基苯甲腈固體重氮鹽的制備[20]。
方法三:在室溫下,將亞硝酸鈉(5 mmol)緩慢加入到濃硫酸(2.5 mL)中,并劇烈攪拌20 min,直到亞硝酸鈉顆粒完全溶解。然后加入丙酸和乙酸的混合溶液6 mL(V丙酸/V乙酸 = 1/5),攪拌30 min后將溶液用冰水浴冷卻至0 ℃。隨后,在10 min內(nèi)加入2-氨基-3-氯-5-硝基苯甲腈(5 mmol)在丙酸(1 mL)和乙酸(5 mL)混合物中的溶液,在0 ℃下攪拌2 h,得到2-氨基-3-氯-5-硝基苯甲腈重氮鹽溶液。該方法還適用于2-氨基-5-硝基噻唑重氮鹽的制備[21]。
1.4 染料E1—E7的合成方法
將中間體2(5 mmol)溶解于DMF(10 mL)中,在冰水浴條件下劇烈攪拌10 min。然后,向該DMF溶液中緩慢加入相應(yīng)重氮鹽(5 mmol),過(guò)程中使用碳酸鈉調(diào)節(jié)體系pH值維持在6~7,滴加完后繼續(xù)攪拌1 h。反應(yīng)完成后,加入水將所得染料析出,過(guò)濾收集固體殘?jiān)?,?jīng)硅膠柱層析(V石油醚/V乙酸乙酯 = 10/1)直接純化得到染料E1—E7。7支染料的表征數(shù)據(jù)如下:
染料E1:產(chǎn)量1.6 g,收率77%;熔點(diǎn)124~126 ℃;1H NMR (CDCl3,400 MHz) δ 7.89 (d,J=9.0 Hz,2H),7.85 (d,J=7.5 Hz,2H),7.48 (dd,J=7.6 Hz,2H),7.39 (dd,J=7.3 Hz,1H),6.83 (d,J=9.1 Hz,2H),4.68 (t,J=6.2 Hz,2H),3.84 (t,J=6.2 Hz,2H),3.56 (q,J=7.1 Hz,2H),1.27 (d,J=7.1 Hz,3H)。13C NMR (CDCl3,101 MHz) δ 172.74,171.00,153.04,149.62,144.03,129.64,129.00,125.37,122.28,111.56,67.05,48.56,46.17,12.41。ESI-HRMS (m/z,C19H18Cl2N6O) 計(jì)算值:417.0992 ([M+H]),實(shí)測(cè)值:417.0992。IR (KBr) ν=2935,2813,1630,1600,1510,1400,1348,1135,1032,800 cm-1。
染料E2:產(chǎn)量1.7 g,收率76%;熔點(diǎn)150~152 ℃;1H NMR (CDCl3,400 MHz) δ 7.87 (d,J=9.0 Hz,2H),7.79 (d,J=8.6 Hz,2H),7.43 (d,J=8.6 Hz,2H),6.82 (d,J=9.1 Hz,2H),4.68 (t,J=6.2 Hz,2H),3.84 (t,J=6.2 Hz,2H),3.57 (q,J=7.0 Hz,2H),1.26 (d,J=3.7 Hz,3H)。13C NMR (CDCl3,101 MHz) δ 172.75,171.00,151.51,149.82,143.91,135.26,129.18,125.46,123.54,111.56,67.02,48.55,46.16,12.41。ESI-HRMS (m/z,C19H17Cl3N6O) 計(jì)算值:451.0602 ([M+H]),實(shí)測(cè)值:451.0602。IR (KBr) ν=2925,2855,1630,1600,1511,1348,1134,1027,801 cm-1。
染料E3:產(chǎn)量2.4 g,收率90%;熔點(diǎn)160~162 ℃; 1H NMR (CDCl3,400 MHz) δ 8.27 (d,J=4.4 Hz,2H),7.94 (d,J=9.0 Hz,2H),6.86 (d,J=9.1 Hz,2H),4.71 (t,J=6.0 Hz,2H),3.89 (t,J=6.0 Hz,2H),3.64-3.59 (m,2H),1.30 (d,J=6.9 Hz,3H)。13C NMR (CDCl3,101 MHz) δ 172.82,170.97,153.98,151.49,145.41,143.83,128.06,126.51,124.29,111.54,66.83,48.63,46.38,12.38。ESI-HRMS (m/z,C19H15Cl4N7O3) 計(jì)算值:532.0034 ([M+H]),實(shí)測(cè)值:532.0036。IR (KBr) ν=2973,2920,2851,1600,1515,1545,1337,1052,854 cm-1。
染料E4:產(chǎn)量1.7 g,收率74%;熔點(diǎn)142~144 ℃;1H NMR (CDCl3,400 MHz) δ 8.33 (d,J=9.0 Hz,2H),7.94 (d,J=3.9 Hz,2H),7.91 (s,2H),6.84 (d,J=9.2 Hz,2H),4.70 (t,J=6.2 Hz,2H),3.92-3.83 (m,2H),3.60 (q,J=7.0 Hz,2H),1.29 (t,J=7.1 Hz,4H)。13C NMR(CDCl3,101 MHz) δ 172.77,170.96,156.60,150.82,147.61,144.11,126.37,124.72,122.74,111.61,66.91,48.57,46.27,12.40。ESI-HRMS (m/z,C19H17Cl2N7O3) 計(jì)算值:462.0843 ([M+H]),實(shí)測(cè)值:462.0843。IR (KBr) ν=2920,2850,1600,1518,1387,1340,1050,802 cm-1。
染料E5:產(chǎn)量2.0 g,收率82%;熔點(diǎn)158~160 ℃;1H NMR (CDCl3,400 MHz) δ 8.61 (d,J=2.4 Hz,1H),8.43 (dd,J=9.1,2.5 Hz,1H),8.02 (s,1H),7.98 (d,J=9.9 Hz,2H),6.85 (d,J=9.3 Hz,2H),4.72 (t,J=6.0 Hz,2H),3.91 (t,J=6.0 Hz,2H),3.63 (q,J=7.1 Hz,2H),1.31 (s,3H)。13C NMR (CDCl3,101 MHz) δ 172.82,170.91,157.48,152.22,146.56,144.50,129.08,128.23,127.82,117.98,115.56,112.28,111.83,66.83,48.66,46.50,12.41。ESI-HRMS (m/z,C20H16Cl2N8O3) 計(jì)算值:487.0795 ([M+H]),實(shí)測(cè)值:487.0795。IR (KBr) ν=2926,2854,1732,1630,1601,1519,1342,1140,1065,802 cm-1。
染料E6:產(chǎn)量1.9 g,收率73%;熔點(diǎn)170~172 ℃; 1H NMR (CDCl3,400 MHz) δ 8.52 (s,1H),8.48 (s,1H),8.08-8.01 (m,2H),6.85 (d,J=9.0 Hz,2H),4.79-4.67 (m,2H),3.98-3.87 (m,2H),3.64 (q,J=6.9 Hz,2H),1.32 (d,J=7.1 Hz,3H)。13C NMR (CDCl3,101 MHz) δ 172.84,170.89,155.43,152.62,145.50,144.13,133.71,129.22,128.58,127.86,115.99,111.90 ,104.10,66.76,48.70,46.59,12.41。ESI-HRMS (m/z,C20H15Cl3N8O3) 計(jì)算值:521.0405 ([M+H]),實(shí)測(cè)值:521.0405。IR (KBr) ν=2920,2852,1630,1603,1513,1341,1134,1051,802 cm-1。
染料E7:產(chǎn)量1.7 g,收率73%;熔點(diǎn)162~164 ℃; 1H NMR (CDCl3,400 MHz) δ 8.62 (s,1H),7.99 (d,J=9.3 Hz,2H),6.88 (d,J=9.3 Hz,2H),4.72 (t,J=6.1 Hz,2H),3.93 (t,J=6.1 Hz,2H),3.66 (q,J=7.1 Hz,2H),1.33 (t,J=7.1 Hz,3H)。13C NMR (CDCl3,101MHz) δ 181.06,173.00,170.98,169.74,153.45,147.57,143.77,143.42,112.40,66.72,48.87,46.87,12.57。ESI-HRMS (m/z,C16H14Cl2N8O3S) 計(jì)算值:469.0359 ([M+H]),實(shí)測(cè)值:469.0359。IR (KBr) ν=2927,2851,1698,1600,1513,1228,1104,1052,790 cm-1。
1.5 印花方法
1.5.1 染料預(yù)處理
將染料(5 g)、分散劑NNO(10 g)、去離子水(40 mL)和鋯珠(Φ 0.2 mm,30 g)加入實(shí)驗(yàn)室微型研磨裝置中。在室溫下研磨1 h后,過(guò)濾,得到染料分散液。向?yàn)V液中補(bǔ)充去離子水,將分散液體積定容至80 mL。
1.5.2 印花漿料的制備
將硫酸鈉(0.75 g,3%(質(zhì)量分?jǐn)?shù),下同)),碳酸氫鈉(0.5 g,2%)和尿素(2 g,8%)加入到活性分散染料的分散液(4、8、12、16 mL和20 mL)中。攪拌,待固體完全溶解后,加入海藻酸鈉(0.55 g,2.2%)。然后,加入額外的水,使總質(zhì)量為25 g (100%)。將混合物攪拌1 h,得到含有質(zhì)量分?jǐn)?shù)為1%、2%、3%、4%或5%活性分散染料的印花色漿。
1.5.3 錦綸織物的印花
使用印花色漿(25 g)在室溫下通過(guò)磁力印花機(jī)在錦綸織物(10 cm×20 cm)上印制色塊,然后在60 ℃的烘箱中干燥10 min,并在102 ℃下汽蒸10 min。冷卻至室溫后,用自來(lái)水洗滌織物,皂洗(浴比50∶1,皂片5 g/L,碳酸鈉2 g/L,80 ℃,30 min),再用自來(lái)水洗滌,得到印花錦綸織物。
1.6 染料及染色織物性能測(cè)試方法
1.6.1 染料的紫外-可見(jiàn)吸收光譜測(cè)試方法
準(zhǔn)確稱取100 mg染料置于100 mL容量瓶中,加入DMF將其充分溶解,并定容到標(biāo)準(zhǔn)刻度,得到染料母液。然后用移液管吸取一定量的母液稀釋成濃度為3×10-5 mol/L的待測(cè)液。采用紫外-可見(jiàn)分光光度計(jì)測(cè)得染料在DMF溶液中的紫外-可見(jiàn)吸收光譜,并記錄可見(jiàn)光區(qū)最大吸收波長(zhǎng)處的吸光度。
1.6.2 染料熱性質(zhì)的測(cè)定
預(yù)熱熱重分析儀并打開(kāi)軟件進(jìn)行校準(zhǔn),用坩堝裝取制備好的E1—E7染料樣品放入儀器內(nèi),于氮?dú)夥障逻M(jìn)行熱重分析測(cè)試(染料3~10 mg,升溫速率10 ℃/min,溫度范圍25~800 ℃)。
1.6.3 顏色深度的測(cè)定
用K/S曲線記錄了錦綸織物在最大波長(zhǎng)處的色深(K/S)值?!癒/S”值由Kubelka-Munk方程計(jì)算得出,每個(gè)樣品測(cè)定表面3個(gè)不同位置處的色深值,取平均值,按式(1)計(jì)算:
K/S=(1-R)22R(1)
式中:K是吸收系數(shù),S是散射系數(shù),R是染色樣品的反射系數(shù)。
1.6.4 勻染性的測(cè)定
織物勻染性按式(2)計(jì)算:
ΔE=1n[(M-X1)2+(M-X2)2+···+(M-Xn)2](2)
式中:Xn為織物上任意一點(diǎn)的K/S值,M為織物上所測(cè)K/S值的平均值。
1.6.5 固色率的測(cè)定
剪取1 g染色錦綸織物,將其浸泡在120 ℃的DMF(10 mL)中。10 min后,若DMF呈現(xiàn)染料的顏色,則用新的DMF進(jìn)行替換,直到織物上不再有染料溶解到DMF中。然后將錦綸織物取出,用自來(lái)水洗滌并在空氣中晾干。固色率f按式(3)計(jì)算:
f/%=(K/S)2(K/S)1×100(3)
式中:(K/S)1為染色錦綸剝色前的K/S值,(K/S)2為染色錦綸剝色后的K/S值。
1.6.6 色牢度的測(cè)定
各類色牢度按相關(guān)國(guó)家標(biāo)準(zhǔn)進(jìn)行測(cè)試:耐皂洗色牢度參照國(guó)標(biāo)GB/T 3921—2008《紡織品 色牢度試驗(yàn) 耐皂洗色牢度》進(jìn)行測(cè)試。耐摩擦色牢度參照國(guó)標(biāo)GB/T 3920—2008《紡織品 色牢度試驗(yàn) 耐摩擦色牢度》進(jìn)行測(cè)試。耐升華色牢度參照國(guó)標(biāo)GB/T 5718—1997《紡織品 色牢度試驗(yàn) 耐干熱(熱壓除外)色牢度》進(jìn)行測(cè)試。耐日曬色牢度按GB/T 8427—2019《紡織品 色牢度試驗(yàn) 耐人造光色牢度:氙弧》測(cè)定。
1.6.7 耐遷移性測(cè)試
剪取一塊大小為5 cm×5 cm的染色錦綸織物(3%質(zhì)量分?jǐn)?shù)染料處理),記為樣品A。另剪取一塊同等面積、同等質(zhì)量未被染色的錦綸織物,記為樣品B。將樣品A和樣品B緊密縫合在一起后,放入染色缸進(jìn)行加熱測(cè)試(測(cè)試條件:浴比1∶30,pH值9,起始溫度25 ℃,升溫速率2 ℃/min,保溫溫度90 ℃,保溫時(shí)間1 h)。待冷卻后,將織物取出、洗凈、晾干,測(cè)試織物的K/S值,并按式(4)確定計(jì)算顏色遷移率M:
M/%=(K/S)B(K/S)A×100(4)
式中:(K/S)A是樣品A處理后的K/S值,(K/S)B是樣品B處理后的K/S值。
1.6.8 機(jī)械性能測(cè)試方法
織物斷裂強(qiáng)力參照 GB/T 3923.1—2013《紡織品 織物拉伸性能 第1部分:斷裂強(qiáng)力和斷裂伸長(zhǎng)率的測(cè)定(條樣法)》進(jìn)行測(cè)試。
2 結(jié)果與討論
2.1 染料 E1—E7的合成路線設(shè)計(jì)與表征
染料E1—E7的化學(xué)結(jié)構(gòu)及相應(yīng)的合成路線如圖1所示。首先,N-乙基-N-羥乙基苯胺與三聚氯
氰發(fā)生親核置換反應(yīng)得到中間體2,該步驟的反應(yīng)收率為82%。隨后,中間體2與相應(yīng)的重氮鹽發(fā)生偶合反應(yīng)得到活性分散染料E1—E7,該步驟的反應(yīng)收率為73%~90%。染料E1—E7經(jīng)核磁共振波譜、傅里葉紅外光譜、高分辨質(zhì)譜等手段進(jìn)行表征確認(rèn)。
圖2為染料E1—E7的1H NMR譜圖。以染料E1為例,在芳香區(qū),化學(xué)位移位于7.89和7.85處的雙峰、7.48和7.39處的dd峰分別歸屬于Hb、Ha、Hc和Hd;化學(xué)位移位于6.83處的雙峰由于偶合常數(shù)與Hb相同,故該峰應(yīng)歸屬于He;在脂肪區(qū),化學(xué)位移處于4.68和3.84處的三重峰分別歸屬于Hf和Hg;化學(xué)位移位于3.56處的四重峰和1.27處的三重峰分別歸屬于Hh和Hi。同理,采用上述方法對(duì)染料E2-E7的1H NMR譜進(jìn)行分析,結(jié)果表明譜圖的峰型及位移等信息均與染料結(jié)構(gòu)相對(duì)應(yīng)。
2.2 染料E1—E7的吸收特性
將染料E1—E7溶解在DMF中,配制成濃度為3×10-5 mol/L的溶液,采用紫外-可見(jiàn)分光光度計(jì)測(cè)得溶液的吸收光譜,結(jié)果如圖3所示。相應(yīng)的最大吸收波長(zhǎng)(λmax)、半峰寬(FWHM)和摩爾吸光系數(shù)(ε)等參數(shù)列于表1中。染料E1—E7在DMF溶液中分別呈現(xiàn)出黃、紅、紫、藍(lán)等顏色,其最大吸收波長(zhǎng)范圍為420~590 nm。在該染料體系中,若染料分子重氮組分結(jié)構(gòu)吸電子能力越強(qiáng),分子內(nèi)電荷轉(zhuǎn)移能力越強(qiáng),則染料在可見(jiàn)光區(qū)的吸收波長(zhǎng)越紅移。染料E1—E7的摩爾消光系數(shù)范圍為27100~35700 L/(mol·cm),半峰寬范圍為93~149 nm。重氮組分結(jié)構(gòu)吸電子能力越強(qiáng),半峰寬越大,顏色越顯暗淡。
2.3 染料E1—E7的熱穩(wěn)定性
使用熱重分析儀測(cè)試了染料E1—E7從室溫加熱到800 ℃時(shí)的質(zhì)量變化情況,結(jié)果如圖4所示。染料E1—E7失重5%的溫度范圍為160~200 ℃。本文采用印花方式染色錦綸織物時(shí)所需汽蒸溫度為102 ℃,該溫度遠(yuǎn)低于7支染料的熱分解溫度。因此,染料E1—E7將在本文設(shè)定的錦綸織物印花流程中具有較好的耐熱穩(wěn)定性。
2.4 染色錦綸織物的顏色特性
考慮到所合成活性分散染料的疏水性,為使染料能成功且方便地應(yīng)用在錦綸織物上,參照活性染料的印花工藝,設(shè)置了相應(yīng)的印花工藝流程,如圖5所示。首先,將染料E1—E7進(jìn)行研磨分散并制備成印花色漿。然后,用磁棒印花機(jī)將色漿均勻地印制在錦綸織物上,采用汽蒸方式將染料滲透并固著在錦綸織物上。最后,將印制的錦綸織物進(jìn)行水洗、皂洗、晾干,得到染色錦綸織物樣品。
使用染料E1—E7配制質(zhì)量分?jǐn)?shù)為3%的色漿對(duì)錦綸進(jìn)行染色,所得染色錦綸的顏色參數(shù)見(jiàn)表2。染料E1—E7染色錦綸織物的顏色分別呈現(xiàn)出黃、紅、紫、藍(lán)等顏色,其最大吸收波長(zhǎng)在420~570 nm的范圍內(nèi)。K/S值在8.8~20.4的范圍內(nèi)。L*值在20.5~79.3的范圍內(nèi),a*值在8.2~46.2的范圍內(nèi),b*值在-16.9~85.0的范圍內(nèi)。染料E1—E7染色錦綸織物的色差ΔE的范圍在0.16~0.28,都小于0.5。較小的色差值表明染料E1—E7染色錦綸織物具有良好的勻染性能。
2.5 染色錦綸織物的固色率
為檢驗(yàn)染色錦綸織物的固色效果,以DMF為溶劑,在120 ℃條件下對(duì)染色錦綸織物進(jìn)行剝色。在首次剝色時(shí),錦綸織物上未能與纖維反應(yīng)的染料會(huì)溶于DMF,但在進(jìn)行第二遍剝色時(shí),剝色液已幾乎看不出顏色,而錦綸織物上還留有很深的顏色。測(cè)試DMF剝色前后染色織物的色深值,并由1.6.5節(jié)式(3)計(jì)算染色錦綸織物的固色率,結(jié)果如圖6所示。其中,E1的固色率最高,達(dá)到90%以上。E5的固色率最低,在74%左右。其余5支染料染色錦綸的固色率均在80%以上。作為對(duì)比,采用相同方法將分散藍(lán)SE-3RT對(duì)錦綸織物進(jìn)行染色。該染色織物經(jīng)DMF第一次剝色后,染料便從錦綸上全部剝離。該對(duì)比結(jié)果表明:在偶氮染料結(jié)構(gòu)中引入三嗪活性基團(tuán),可使染色錦綸織物具有良好的固色效果。
2.6 染料質(zhì)量濃度對(duì)色深和固色率的影響
研究了染料濃度對(duì)染色錦綸織物K/S值與固色率的影響,結(jié)果如圖7所示。將色漿中E1的質(zhì)量分?jǐn)?shù)從1%增加到3%時(shí),錦綸織物的K/S值從5.1提升至10.2。此時(shí),隨著染料濃度的提升,染料在織物上的擴(kuò)散和吸附量增大。繼續(xù)增加E1的質(zhì)量分?jǐn)?shù),K/S值達(dá)到飽和,不再明顯提升。漿料中染料E1的質(zhì)量分?jǐn)?shù)從1%提高到5%時(shí),染色錦綸織物都具有較高的固色率,固色率都在90%及以上。這是因?yàn)榇蟛糠治磁c纖維反應(yīng)的染料極易被皂洗清除,使得染色錦綸織物具有高固色效果。染料E2-E7染色錦綸織物K/S值和固色率隨染料質(zhì)量分?jǐn)?shù)的變化規(guī)律與E1相似。除染料E5染色織物固色率略低(70%~80%之間)外,其他染料染色織物固色率均在80%~90%之間。
2.7 染色錦綸織物的色牢度
評(píng)估了經(jīng)染料E1—E7染色錦綸織物的色牢度,列于表3中。染料本身的疏水性及其對(duì)錦綸纖維的反應(yīng)性使得染色錦綸織物的耐皂洗、耐摩擦和耐升華色牢度均可達(dá)4級(jí)及以上。作為對(duì)比,分散藍(lán)SE-3RT染色錦綸織物的各項(xiàng)色牢度等級(jí)明顯較差。常規(guī)分散染料與纖維間親和力只有氫鍵和范德華力等弱作用力,染色織物在皂洗、摩擦或高溫作用下容易使染料分子遷移,甚至離開(kāi)纖維?;钚苑稚⑷玖峡墒谷玖戏肿永喂探Y(jié)合在纖維上,從而顯著提升染色織物色牢度等級(jí)。染料E1—E7染色織物中,淺色織物的耐日曬色牢度較好,可達(dá)5~6級(jí),深色織物的耐日曬色牢度略低,僅有3級(jí)。
2.8 染色錦綸織物的遷移性
測(cè)試了染料E1—E7染色錦綸織物的顏色遷移率,結(jié)果如圖8所示。與分散藍(lán)SE-3RT相比,染料E1—E7染色錦綸織物不僅K/S值高,且顏色遷移率均在5%以下。分散藍(lán)SE-3RT染色錦綸織物的遷移率則在30%左右。常規(guī)分散染料由于僅能以氫鍵、范德華力等弱作用力吸附在纖維表面,不僅使染色織物得色低,而且容易從染色織物遷移到貼襯上。染料E1—E7因可與纖維以共價(jià)鍵結(jié)合而難以從染色織物上脫落,因此,染色織物具有較低的顏色遷移率。
2.9 染色錦綸織物的機(jī)械性能
測(cè)定了染料E1—E7染色錦綸織物的機(jī)械性能,結(jié)果如圖9所示。錦綸原布的斷裂強(qiáng)力為450 N,斷裂伸長(zhǎng)率為114%。染料E1—E7染色錦綸織物的斷裂強(qiáng)力范圍為416~446 N,與原布相比,強(qiáng)力下降約1.0%~7.6%。染色織物的斷裂伸長(zhǎng)率在97%~125%之間。整體上看,采用印花方式對(duì)錦綸進(jìn)行染色的條件較為溫和,該染色工藝不會(huì)對(duì)機(jī)械性能造成顯著影響。
3 結(jié)論
本文設(shè)計(jì)在偶氮發(fā)色體的羥乙基上引入二氯均三嗪結(jié)構(gòu),采用縮合和偶合兩步法合成了7支偶氮型活性分散染料E1—E7,并探討了該類染料對(duì)錦綸織物的染色性能。主要結(jié)論如下:
a)縮合反應(yīng)收率為82%,偶合反應(yīng)收率為73%~90%。所得染料最大吸收波長(zhǎng)分布于420~590 nm,摩爾消光系數(shù)范圍為27100~35700 L/(mol·cm)。
b)采用印花方式對(duì)錦綸進(jìn)行染色,所得染色織物具有良好的得色率、鮮艷性和勻染性,且織物機(jī)械性能受影響較小。
c)引入二氯均三嗪結(jié)構(gòu)顯著增強(qiáng)染色錦綸的固色效果。染色錦綸織物的固色率達(dá)到74%~90%,耐皂洗、耐摩擦和耐升華色牢度可達(dá)4級(jí)及以上,顏色遷移率均不超過(guò)5%。
上述結(jié)果為偶氮型活性分散染料的分子設(shè)計(jì)及其對(duì)錦綸織物的染色應(yīng)用提供了有益參考。
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Preparation and properties of reactive disperse dyes for nylon printing
DING" Guoqing," JIANG" Hua
(Engineering Research Center for Eco-Dyeing amp; Finishing of Textiles, Ministry of Education,
Zhejiang Sci-Tech University, Hangzhou 310018, China)
Abstract:
Nylon, also known as aliphatic polyamide fiber, exhibits excellent performance, such as light weight, elasticity, good thermal stability, and mechanical property. Nylon has been widely used in the manufacturing of sportswear, stockings, conveyor belts, tents, industrial fabrics, and others. Nylon can be dyed by using acid dyes, reactive dyes, or disperse dyes. Nylon fabrics dyed with acid dyes offer vibrant color shades. However, their wet fastness is relatively poor. By employing reactive dyes, the dye molecules can form covalent bonds with nylon fibers by reacting with the amino end groups. Therefore, good color fastness to wet treatment can be achieved. However, reactive dyes usually display limited deep dyeing on nylon. And, the deeper the color, the more noticeable the reduction in color fastness. Dyeing of nylon with disperse dyes provides good levelness and penetration, while" exhibits poor color fastness property due to the low affinity between dyes and fibers. Reactive disperse dyes, which are constructed by attaching reactive groups to hydrophobic chromophores, combine the advantages of disperse dyes and reactive dyes. Currently, the most common approach to design reactive disperse dyes involves combining triazine and azo structures. This design concept is simple, effective, and allows for easy synthesis. However, reported molecular designs often directly combine the triazine structure with the primary amino group on the azo structure, greatly impacting the electronic effect of the azo chromophore and consequently affecting the color of the dye.
This paper aimed to design seven reactive disperse dyes, E1—E7, by introducing dichlorotriazine moiety onto the hydroxyethyl group of the azo chromophore, and to synthesize the designed dyes by using a two-step method including condensation reaction and coupling reaction. The structures of these dyes were characterized and confirmed by nuclear magnetic resonance spectroscopy, Fourier infrared spectroscopy, and high-resolution mass spectrometry. Nylon fabrics were dyed with reactive disperse dyes with a printing process. The composition for the printing paste was as follows: dye x%, Na2SO4 3%, NaHCO3 2%, urea 8%, sodium alginate 2.2%, and water. The printing process was performed under the condition of drying at 60 ℃ and steaming at 102 ℃. The properties of the dyed nylon fabrics, such as levelness, color depth, fixation value, color fastness, migration value, and breaking strength were tested.
The results indicate that the colors of nylon fabrics dyed with dyes E1—E7 show various colors of yellow, red, purple, and blue, respectively, with a color difference ΔE ranging from 0.16 to 0.28, which indicates good level dyeing performance. Nylon fabrics dyed with E1—E7 exhibit excellent resistance to organic solvent extraction. In comparison, the color of conventional disperse dye Disperse Blue SE-3RT on dyed nylon fabric can be completely stripped off by DMF. As calculated, dye E1 has the highest fixation value, reaching over 90%, while dye E5 has the lowest color fixation value of 74%. The other five dyes exhibit fixation values of above 80%. Due to the covalent bonding between reactive disperse dyes and fibers, the dyed nylon fabric demonstrates a good color fixing property. The nylon fabrics dyed with dyes E1—E7 exhibit color fastnesses to washing, rubbing, and sublimation of grade 4 or above. The dye migration values of dyed nylon fabrics are less than 5%. The breaking strengths of the nylon fabrics dyed with dyes E1—E7 range from 416 to 446 N, with a decrease in strength of only 1% to 7.6%, as compared with the original nylon fabric. This indicates that the dyeing of nylon fabric using dyes E1—E7 will not significantly damage the mechanical property.
The above results provide a new approach for the molecular design of azo-type reactive disperse dyes and their application in dyeing of nylon fabrics.
Keywords:
reactive disperse dyes; nylon; dyeing; fixation value; color fastness