改性纳米薯渣纤维素的制备优化及其形貌表征
发布时间：2019-06-18 16:17
【摘要】：对纳米纤维素(cellulose nanocryslal,CNC)进行羧甲基化改性,以提高其再分散性。以取代度(degree substitution,DS)为响应值,利用响应面法(response surface methodology,RSM)优化羧甲基纳米纤维素(N-CMC)的制备工艺,并运用透射电镜(TEM)对改性前后的CNC进行形貌表征,研究羧甲基改性对纳米纤维素结构的影响。结果表明:对N-CMC取代度有显著影响的4个因素为,Na OH/CNC质量比、Na OH/一氯乙酸(MCA)摩尔比、醚化Ⅰ段温度和醚化Ⅰ段时间;中心组合设计结合RSM分析确定主要影响因素的最佳水平组合为,Na OH/CNC质量比1.44、Na OH/MCA摩尔比2.40、醚化I段温度50℃、醚化I段时间50 min,此条件下N-CMC取代度的平均值为1.343±0.015,与理论预测值1.364相符。TEM分析显示,改性后的CNC仍保持了球形的结晶结构,只是粒径略有增大,且表面结构更加疏松。羧甲基取代纳米纤维素表面的部分羟基,并未显著影响其结晶结构,且有利于其在极性介质中的再分散。
[Abstract]:Nano-cellulose (cellulose nanocryslal,CNC) was modified by carbomethylation to improve its redispersibility. Using substitution degree (degree substitution,DS) as response value, the preparation process of carboxymethyl nanocellulose (N-CMC) was optimized by response surface method (response surface methodology,RSM). The morphology of CNC before and after modification was characterized by transmission electron microscope (TEM). The effect of carboxymethyl modification on the structure of nano-cellulose was studied. The results showed that the four factors that had significant effect on the degree of substitution of N-CMC were Na OH/CNC mass ratio, (MCA) molar ratio of Na OH/ monochloroacetic acid, etherification stage I temperature and etherification time. The optimum horizontal combination of Na OH/CNC mass ratio 1.44, Na OH/MCA molar ratio 2.40, etherification I temperature 50 鈩，
本文编号：2501624
[Abstract]:Nano-cellulose (cellulose nanocryslal,CNC) was modified by carbomethylation to improve its redispersibility. Using substitution degree (degree substitution,DS) as response value, the preparation process of carboxymethyl nanocellulose (N-CMC) was optimized by response surface method (response surface methodology,RSM). The morphology of CNC before and after modification was characterized by transmission electron microscope (TEM). The effect of carboxymethyl modification on the structure of nano-cellulose was studied. The results showed that the four factors that had significant effect on the degree of substitution of N-CMC were Na OH/CNC mass ratio, (MCA) molar ratio of Na OH/ monochloroacetic acid, etherification stage I temperature and etherification time. The optimum horizontal combination of Na OH/CNC mass ratio 1.44, Na OH/MCA molar ratio 2.40, etherification I temperature 50 鈩，
本文编号：2501624
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