【摘要】：對納米纖維素(cellulose nanocryslal,CNC)進(jìn)行羧甲基化改性,以提高其再分散性。以取代度(degree substitution,DS)為響應(yīng)值,利用響應(yīng)面法(response surface methodology,RSM)優(yōu)化羧甲基納米纖維素(N-CMC)的制備工藝,并運(yùn)用透射電鏡(TEM)對改性前后的CNC進(jìn)行形貌表征,研究羧甲基改性對納米纖維素結(jié)構(gòu)的影響。結(jié)果表明:對N-CMC取代度有顯著影響的4個(gè)因素為,Na OH/CNC質(zhì)量比、Na OH/一氯乙酸(MCA)摩爾比、醚化Ⅰ段溫度和醚化Ⅰ段時(shí)間;中心組合設(shè)計(jì)結(jié)合RSM分析確定主要影響因素的最佳水平組合為,Na OH/CNC質(zhì)量比1.44、Na OH/MCA摩爾比2.40、醚化I段溫度50℃、醚化I段時(shí)間50 min,此條件下N-CMC取代度的平均值為1.343±0.015,與理論預(yù)測值1.364相符。TEM分析顯示,改性后的CNC仍保持了球形的結(jié)晶結(jié)構(gòu),只是粒徑略有增大,且表面結(jié)構(gòu)更加疏松。羧甲基取代納米纖維素表面的部分羥基,并未顯著影響其結(jié)晶結(jié)構(gòu),且有利于其在極性介質(zhì)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，

本文編號：2501624