徐元媛,孟 露,趙毅哲,吳夢謠,于宏偉
(石家莊學院 化工學院,河北 石家莊 050035)
粘膠纖維是以天然纖維素(漿粕)為原料,利用纖維素黃酸酯溶液,經(jīng)過紡制形成的再生纖維素纖維。粘膠纖維性能與棉纖維具有很大相似之處,吸濕性能較強,容易上色,具有較好的可紡性,廣泛應用于織造、制絨、制線、針織等領域[1-6]。中紅外(MIR)光譜具有方便、快捷的優(yōu)點[7-11]廣泛應用于常溫下粘膠纖維結構研究領域[12-13]。不同溫度下,粘膠纖維熱穩(wěn)定性是紡織行業(yè)相關技術人員所關心的重要技術領域,但相關研究少見報道。變溫中紅外(TD-MIR)光譜應用于化合物熱穩(wěn)定性研究領域[14-23],并能提供更加豐富的光譜信息。本文采用MIR及TD-MIR光譜,開展了粘膠纖維的結構及熱穩(wěn)定性研究,為我國相關企業(yè)粘膠纖維產(chǎn)品開發(fā)及應用,提供了重要的科學參考。
粘膠纖維(浙江瑞康日用品有限公司生產(chǎn))
Spectrum 100型傅里葉紅外光譜儀(美國PE公司),Golden Gate型單次內(nèi)反射ATR-FTIR附件。
303 K的溫度條件下,以空氣為背景,每次對于信號進行8次掃描累加,MIR光譜數(shù)據(jù)的獲得采用PE公司Spectrum v 6.3.5軟件。
采用MIR光譜開展了粘膠纖維分子結構研究(圖1)。
圖1 粘膠纖維分子MIR光譜(303 K)
首先采用一維MIR光譜開展了粘膠纖維分子結構的研究(圖1A)。實驗發(fā)現(xiàn):3308.21cm-1和3299.89cm-1處的吸收峰是粘膠纖維分子O-H伸縮振動模式(νO-H-粘膠纖維-一維);2924.62cm-1處的吸收峰是粘膠纖維分子CH2不對稱伸縮振動模式(νasCH2-粘膠纖維-一維);1076.68cm-1(νC-O-1-粘膠纖維-一維)、1012.09cm-1(νC-O-2-粘膠纖維-一維) 和 993.65cm-1(νC-O-3-粘膠纖維-一維)處的吸收峰是粘膠纖維分子CO伸縮振動模式(νC-O-粘膠纖維-一維)。進一步開展了粘膠纖維分子的二階導數(shù)MIR光譜(圖1B)、四階導數(shù)MIR光譜(圖1C)及去卷積MIR光譜研究(圖1D),相關光譜數(shù)據(jù)見表1。
表1 粘膠纖維分子的MIR光譜數(shù)據(jù)(303 K)
MIR光譜 粘膠纖維分子官能團紅外吸收頻率及強度cm-1(A)四階導數(shù)MIR光譜3820.15(0.00),2324.83(0.00),2177.92(0.00),2161.55(0.00),2139.82(0.00),2051.07(0.00),2009.66(0.00),1980.03(0.00),1074.66(0.00),667.66(0.00),660.39(0.00),627.43(0.00),620.48(0.00),608.59(0.00);去卷積MIR光譜3867.86(0.01),3827.67(0.01),3820.90(0.04),3814.68(0.01),3751.61(0.01),3690.40(0.01),3673.31(0.01),3649.97(0.02),3307.95(0.06),2925.97(0.04),2346.01(0.01),2339.59(0.01),2333.90(0.01),2324.66(0.03),2285.05(0.01),2234.11(0.01),2189.09(0.01),2184.23(0.02),2178.25(0.02),2167.33(0.02),2161.03(0.06),2155.71(0.01),2147.27(0.01),2140.30(0.01),2127.99(0.01),2107.97(0.01),2083.52(0.01),2060.25(0.01),2056.11(0.01),2051.11(0.04),2046.83(0.01),2042.35(0.02),2035.29(0.01),2027.92(0.01),2022.99(0.01),2015.13(0.01),2009.77(0.02),2003.14(0.01),1991.88(0.02),1979.36(0.05),1974.76(0.01),1962.99(0.01),1955.01(0.01),1947.95(0.01),1908.14(0.01),1868.41(0.01),1703.14(0.01),1687.14(0.02),1683.76(0.03),1678.67(0.02),1655.70(0.02),1652.04(0.03),1647.02(0.03),1614.86(0.02),1577.51(0.03),1570.85(0.02),1567.01(0.02),1562.98(0.02),1559.90(0.06),1556.67(0.03),1541.22(0.02),1534.82(0.02),1523.05(0.02),1511.03(0.02),1507.92(0.03),1504.73(0.02),1491.21(0.02),1475.64(0.03),1471.96(0.04),1467.50(0.03),1463.91(0.04),1459.95(0.04),1456.12(0.05),1439.68(0.03),1435.91(0.04),1427.44(0.04),1422.97(0.04),1418.58(0.04),1372.94(0.04),1147.47(0.08),1103.05(0.08),1075.37(0.12),1043.17(0.13),1015.48(0.17),1011.41(0.17),1007.23(0.17),1003.06(0.17),991.24(0.18),927.29(0.08),843.94(0.06),814.88(0.05),787.14(0.06),763.25(0.07),740.00(0.06),731.74(0.06),723.24(0.07),718.99(0.08),711.55(0.08),707.28(0.09),703.04(0.09),695.98(0.09),691.21(0.09),687.00(0.08),683.15(0.08),679.05(0.08),673.10(0.08),671.02(0.10),667.55(0.20),662.11(0.10),659.08(0.10),655.20(0.08),650.99(0.11),643.19(0.09),639.10(0.08),635.35(0.09),631.45(0.10),626.97(0.12),619.88(0.12),615.17(0.13),610.81(0.12),607.37(0.14),603.00(0.13);
由表1數(shù)據(jù)研究發(fā)現(xiàn),粘膠纖維分子的二階導數(shù)MIR光譜及四階導數(shù)MIR光譜并不能增加原譜圖(一維MIR光譜)的分辨能力,而去卷積MIR光譜則過于復雜,給粘膠纖維分子官能團歸屬帶來一定的困難。
在4000 cm-1~600 cm-1頻率范圍內(nèi),采用一維TD-MIR光譜進一步開展了溫度變化對于粘膠纖維分子結構的影響(圖2)。
圖2 粘膠纖維分子一維TD-MIR光譜(4000 cm-1~600 cm-1)
實驗發(fā)現(xiàn):粘膠纖維分子主要官能團的吸收頻率集中在“4000 cm-1~3000 cm-1” 、“3000 cm-1~2800 cm-1”及“1100 cm-1~950 cm-1” 等3個頻率區(qū)間。
2.2.1 第1頻率區(qū)間粘膠纖維分子一維TD-MIR光譜研究
首先在第1頻率區(qū)間開展了粘膠纖維分子熱穩(wěn)定性研究(圖3)。
圖3 粘膠纖維分子一維TD-MIR光譜(4000 cm-1~3000 cm-1)
實驗發(fā)現(xiàn),隨著測定溫度的升高,粘膠纖維分子νO-H-粘膠纖維-一維對應的吸收頻率出現(xiàn)了藍移趨勢,對應的吸收強度略有增加。這主要是因為,溫度的增加,進一步破壞了粘膠纖維分子內(nèi)及分子間的氫鍵作用,而出現(xiàn)了更多的游離羥基,相關光譜信息見表2。
表2 粘膠纖維分子的一維TD-MIR光譜數(shù)據(jù)(303 K~393 K)
溫度K 粘膠纖維分子官能團紅外吸收頻率及強度cm-1(A)1716.18(0.01),1635.35(0.02),1545.63(0.01),1534.81(0.01),1409.52(0.04),1361.69(0.04),1335.59(0.04),1240.49(0.03),1204.60(0.03),1147.66(0.08),1076.02(0.11),1010.77(0.17),993.22(0.18),932.66(0.08),851.09(0.06),758.17(0.07),704.10(0.08),688.00(0.07),667.44(0.08),658.50(0.08),635.55(0.09),610.47(0.10),604.40(0.10);343 3966.02(0.00),3947.17(0.00),3933.07(0.00),3918.10(0.00),3902.98(0.00),3884.79(0.00),3868.36(0.00),3859.88(0.00),3853.38(0.00),3843.27(0.00),3821.14(0.00),3812.64(0.00),3805.11(0.00),3770.69(0.00),3759.69(0.00),3750.30(0.00),3738.03(0.00),3726.30(0.00),3712.71(0.00),3704.39(0.00),3680.00(0.00),3671.42(0.00),3649.95(0.00),3366.86(0.06),3333.44(0.06),3316.78(0.06),2926.61(0.04),2717.65(0.01),2619.91(0.01),2583.62(0.01),2571.12(0.01),2546.41(0.01),2534.85(0.01),2518.78(0.01),2509.36(0.01),2483.92(0.01),2470.32(0.01),2431.31(0.01),2421.15(0.01),2405.07(0.01),2375.07(0.01),2366.79(0.01),2358.74(0.01),2351.62(0.01),2339.59(0.01),2333.06(0.01),2306.88(0.01),2260.03(0.01),2247.76(0.01),2239.16(0.01),2227.72(0.01),2219.96(0.01),2198.91(0.01),2186.86(0.01),2179.23(0.01),2174.70(0.01),2165.47(0.01),2156.56(0.02),2146.75(0.02),2133.95(0.02),2093.04(0.01),2084.04(0.01),2060.08(0.01),2054.22(0.01),2041.11(0.02),2016.30(0.02),2004.91(0.02),1974.84(0.02),1967.21(0.02),1958.83(0.02),1927.51(0.02),1889.05(0.02),1869.19(0.02),1844.98(0.01),1816.79(0.01),1770.79(0.01),1748.08(0.01),1715.99(0.01),1635.63(0.02),1544.21(0.02),1535.31(0.01),1524.69(0.01),1512.05(0.01),1408.85(0.04),1361.22(0.05),1335.31(0.04),1239.85(0.03),1204.20(0.03),1147.71(0.08),1075.66(0.11),1010.95(0.18),993.59(0.18),932.30(0.09),850.82(0.06),815.09(0.05),759.48(0.07),704.25(0.08),690.71(0.08),655.96(0.09),648.01(0.09),626.79(0.09),604.12(0.11);353 3990.65(0.00),3976.18(0.00),3947.14(0.00),3933.21(0.00),3918.50(0.00),3901.97(0.00),3885.28(0.00),3869.02(0.00),3860.13(0.00),3850.23(0.00),3843.24(0.00),3832.09(0.00),3819.71(0.00),3806.65(0.00),3779.69(0.00),3770.87(0.00),3750.70(0.00),3737.36(0.00),3726.21(0.00),3680.90(0.00),3649.76(0.01),3365.89(0.06),3339.71(0.06),3326.15(0.06),2926.58(0.04),2569.86(0.01),2548.50(0.01),2517.19(0.01),2492.28(0.01),2482.58(0.01),2470.31(0.01),2441.11(0.01),2420.76(0.01),2404.45(0.01),2378.97(0.01),2366.53(0.01),2351.45(0.01),2346.19(0.01),2334.42(0.01),2301.23(0.01),2271.17(0.01),2261.20(0.01),2252.75(0.01),2234.23(0.01),2205.96(0.01),2200.44(0.01),2179.33(0.02),2174.33(0.02),2156.22(0.03),2133.32(0.02),2107.20(0.01),2093.44(0.02),2060.46(0.02),2054.05(0.02),2041.39(0.02),2023.55(0.03),2004.71(0.03),1991.24(0.02),1973.78(0.03),1967.18(0.03),1958.11(0.03),1886.13(0.02),1869.02(0.02),1816.70(0.02),1776.52(0.01),1748.05(0.01),1731.03(0.01),1714.80(0.01),1635.66(0.02),1629.58(0.02),1553.50(0.02),1544.38(0.02),1534.78(0.02),1524.64(0.02),1512.42(0.02),1455.61(0.03),1409.03(0.04),1403.80(0.04),1366.31(0.05),1360.46(0.05),1335.86(0.05),1243.88(0.04),1204.19(0.03),1147.11(0.08),1075.56(0.11),992.37(0.18),931.16(0.09),850.82(0.07),757.88(0.07),706.79(0.08),687.89(0.08),660.93(0.09),651.08(0.09),646.65(0.09),606.91(0.11);363 3974.98(0.00),3948.57(0.00),3933.27(0.00),3918.58(0.00),3901.91(0.00),3884.70(0.00),3868.20(0.00),3843.86(0.00),3823.35(0.00),3817.49(0.00),3805.28(0.00),3737.64(0.00),3725.34(0.00),3692.84(0.00),3680.93(0.00),3649.98(0.01),3341.76(0.06),2926.89(0.04),2616.10(0.01),2544.31(0.01),2509.01(0.01),2490.97(0.01),2421.68(0.01),2404.06(0.01),2377.93(0.01),2366.61(0.01),2352.04(0.01),2332.93(0.01),2301.08(0.01),2261.62(0.01),2252.24(0.01),2206.93(0.02),2200.86(0.02),2193.15(0.02),2179.72(0.02),2174.08(0.02),2156.04(0.04),2146.25(0.03),2133.20(0.03),2106.97(0.02),2093.29(0.02),2059.28(0.02),2054.45(0.02),2040.93(0.02),2023.72(0.03),2013.30(0.03),2004.83(0.04),1967.07(0.03),1958.23(0.04),1869.91(0.02),1816.70(0.02),1776.11(0.02),1748.00(0.02),1733.39(0.02),1715.21(0.02),1635.56(0.02),1603.74(0.02),1545.42(0.02),1534.94(0.02),1528.83(0.02),1514.67(0.02),1455.71(0.03),1409.35(0.04),1403.80(0.04),1361.21(0.05),1345.21(0.05),1336.12(0.05),1241.44(0.04),1204.08(0.03),1147.08(0.08),1075.15(0.12),1010.71(0.18),992.44(0.19),931.07(0.09),850.94(0.07),758.65(0.07),706.54(0.08),691.30(0.08),684.29(0.08),670.83(0.08),655.58(0.09),649.99(0.09),643.57(0.09),606.93(0.11),604.04(0.11);373 3991.25(0.00),3975.74(0.00),3964.49(0.00),3948.46(0.00),3933.04(0.00),3919.18(0.00),3902.39(0.00),3884.32(0.00),3868.27(0.00),3856.16(0.00),3842.65(0.00),3829.55(0.00),3819.17(0.00),3804.83(0.00),3798.82(0.00),3781.72(0.00),3746.92(0.00),3737.12(0.00),3726.59(0.00),3693.60(0.00),3680.88(0.00),3649.81(0.01),3626.80(0.01),3341.07(0.06),2926.94(0.04),2547.67(0.01),2535.06(0.01),2517.40(0.01),2509.02(0.01),2484.39(0.01),2471.19(0.01),2421.05(0.01),2403.85(0.01),2378.99(0.01),2366.07(0.01),2352.08(0.01),2331.45(0.01),2307.07(0.01),2261.53(0.01),2251.91(0.01),2194.89(0.02),2179.74(0.02),2174.04(0.02),2155.99(0.04),2132.93(0.03),2103.72(0.02),2093.19(0.02),2059.50(0.02),2054.52(0.02),2041.50(0.02),2021.14(0.03),2015.08(0.03),2004.80
溫度K 粘膠纖維分子官能團紅外吸收頻率及強度cm-1(A)(0.04),1968.83(0.04),1958.23(0.04),1816.72(0.02),1775.93(0.02),1749.69(0.02),1739.69(0.02),1734.14(0.02),1715.79(0.02),1636.20(0.03),1629.87(0.03),1546.48(0.02),1534.80(0.02),1524.81(0.02),1512.32(0.02),1455.56(0.03),1408.68(0.04),1403.74(0.04),1366.14(0.05),1360.02(0.05),1335.24(0.05),1240.00(0.04),1204.03(0.03),1146.87(0.08),1075.20(0.12),992.88(0.19),930.68(0.09),850.80(0.07),758.16(0.07),704.72(0.08),667.94(0.08),646.64(0.09),604.53(0.11);383 3990.13(0.00),3976.88(0.00),3961.70(0.00),3947.78(0.00,)3933.10(0.00),3918.28(0.00),3902.41(0.00),3887.36(0.00),3868.47(0.00),3856.03(0.00),3843.23(0.00),3828.88(0.00),3805.24(0.00),3797.96(0.00),3782.61(0.00),3769.14(0.00),3747.00(0.00),3737.81(0.00),3726.09(0.00),3704.29(0.00),3693.29(0.00),3679.27(0.00),3649.41(0.01),3610.02(0.01),3366.57(0.06),3352.64(0.06),3340.85(0.06),3324.12(0.06),2927.64(0.04),2518.59(0.01),2503.11(0.01),2491.89(0.01),2483.83(0.01),2470.63(0.01),2421.33(0.01),2403.92(0.01),2378.60(0.02),2366.17(0.02),2352.83(0.02),2332.36(0.01),2305.87(0.01),2261.98(0.01),2251.82(0.02),2200.87(0.02),2187.81(0.02),2179.41(0.03),2174.01(0.03),2155.91(0.05),2132.99(0.04),2093.20(0.03),2060.32(0.03),2054.28(0.03),2040.90(0.03),2013.38(0.04),2004.41(0.05),1973.77(0.05),1967.31(0.05),1958.06(0.05),1816.55(0.03),1776.01(0.02),1748.14(0.02),1738.70(0.02),1721.01(0.02),1715.98(0.02),1700.61(0.02),1635.72(0.03),1602.98(0.03),1553.70(0.02),1544.09(0.02),1534.95(0.02),1512.72(0.02),1455.80(0.04),1409.11(0.05),1403.65(0.05),1398.60(0.05),1366.10(0.05),1360.62(0.05),1336.89(0.05),1238.60(0.04),1204.30(0.03),1146.19(0.09),1074.66(0.12),991.94(0.20),930.55(0.10),849.64(0.07),758.53(0.08),705.38(0.08),667.52(0.09),656.08(0.09),648.08(0.09);393 3990.97(0.00),3976.36(0.00),3961.61(0.00),3947.73(0.00),3933.14(0.00),3918.80(0.00),3902.12(0.00),3885.25(0.00),3868.09(0.00),3860.27(0.00),3852.00(0.00),3841.43(0.00),3826.19(0.00),3813.94(0.00),3805.66(0.00),3798.20(0.00),3781.72(0.00),3737.63(0.00),3725.98(0.00),3681.39(0.00),3649.79(0.01),3626.41(0.01),3359.07(0.06),3340.68(0.06),3011.72(0.02),2928.16(0.04),2507.94(0.01),2474.00(0.01),2421.56(0.02),2403.88(0.02),2380.35(0.02),2366.07(0.02),2352.04(0.01),2330.86(0.01),2306.61(0.01),2261.40(0.02),2251.70(0.02),2201.04(0.02),2179.52(0.03),2173.73(0.03),2155.78(0.06),2132.82(0.05),2093.12(0.03),2060.79(0.03),2054.28(0.03),2042.16(0.03),2013.84(0.05),2004.48(0.06),1972.94(0.06),1958.06(0.06),1816.58(0.03),1776.68(0.02),1749.96(0.02),1739.20(0.02),1733.70(0.02),1715.91(0.02),1700.14(0.02),1635.30(0.03),1613.87(0.03),1603.02(0.03),1557.95(0.02),1553.44(0.02),1544.19(0.02),1534.30(0.02),1513.02(0.02),1500.12(0.02),1455.75(0.04),1403.55(0.05),1391.77(0.05),1360.84(0.05),1336.72(0.05),1241.64(0.04),1204.63(0.04),1145.83(0.09),1074.57(0.13),992.25(0.20),930.90(0.10),850.77(0.07),757.66(0.08),703.27(0.08),645.07(0.09),606.53(0.12);
2.2.2 第2頻率區(qū)間粘膠纖維分子一維TD-MIR光譜研究
進一步在第2頻率區(qū)間開展了粘膠纖維分子熱穩(wěn)定性研究(圖4)。
圖4 粘膠纖維分子一維TD-MIR光譜(3000 cm-1~2800 cm-1)
實驗發(fā)現(xiàn),隨著測定溫度的升高,粘膠纖維分子νasCH2-粘膠纖維-一維對應的吸收頻率出現(xiàn)了藍移趨勢,對應的吸收強度略有增加,相關光譜信息見表2。
2.2.3 第3頻率區(qū)間粘膠纖維分子一維TD-MIR光譜研究
最后在第3頻率區(qū)間開展了粘膠纖維分子熱穩(wěn)定性研究(圖5)。
圖5 粘膠纖維分子一維TD-MIR光譜(1100 cm-1~950 cm-1)
實驗發(fā)現(xiàn),隨著測定溫度的升高,粘膠纖維分子νC-O-1-粘膠纖維-一維和νC-O-3-粘膠纖維-一維對應的吸收頻率出現(xiàn)了紅移趨勢,相應的吸收強度進一步增加;粘膠纖維分子νC-O-2-粘膠纖維-一維則對于溫度變化比較敏感,其對應的吸收峰在373K的溫度下消失,相關光譜信息見表2。
粘膠纖維分子的中紅外吸收模式主要包括:νO-H、νasCH2和νC-O。粘膠纖維分子的二階導數(shù)MIR光譜、四階導數(shù)MIR光譜和去卷積MIR光譜,并沒有增加原光譜的譜圖分辨能力。在303 K~393 K的溫度范圍內(nèi),隨著測定溫度的升高,粘膠纖維分子主要官能團對應的吸收頻率及強度均有一定的改變,其熱穩(wěn)定性進一步降低。