硫酸盐木素磺化改性工艺的研究

采用两步法对硫酸盐木素进行磺化改性。第1步先用甲醛对硫酸盐木素进行羟甲基化改性，通过测定甲醛的消耗率来表征产物羟甲基含量，表明最适宜的羟甲基化反应工艺为：温度80℃，时间120min，pH为12。第2步采用Na2SO3为磺化剂，利用电导滴定法和红外光谱分别测定反应产物的磺化度和磺化改性后产物的结构，结果表明产物磺化度与磺化反应时间有关，最优磺化时间为4h。磺化度可达0．883mmol／g，硫酸盐木素经磺化改性后，仍保持着木素的基本骨架结构，只是分子上引入了磺酸基团。

Study on the Sulfonation Modification of Kraft Lignin

Kraft lignin was modified by two steps sulfonation. Firstly, formaldehyde was used for hydroxymethylation of kraft lignin. Hydroxymethyl group content of product was characterized by determining formaldehyde consumption. The results showed that the optimal hydroxymethylation reaction conditions were： temperature 80 ℃, time 120 mins and pH 12. Secondly, Na2SO3 was used as sulfonating agent. The sulfonation degree of lignosulfonate was determined by eonductometric titration and the modified products were also analyzed by IR spectra. The results showed that the sulfonation degree of the products was related to sulfonatioon reaction time. It was found that the optimal time of sulfonation was 4 hours, when sulfonation degree could reach 0.883 mmol/g. Kraft lignin was introduced with suffonic groups after sulfonation modification while its basic skeleton structure was still remained.