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对羧甲基壳聚糖(CMCS)进行选择性氧化改性,制备双醛羧甲基壳聚糖(DCMCS)。结果表明:DCMCS具有良好的保湿性及对纸张的增强作用,因而可用做纸张增强、保湿方面的新型助剂。采用FTIR、XRD和1 H-NMR对产物结构进行表征,证实随着氧化剂用量的增加,在羧甲基壳聚糖的C2、C3位均有醛基生成,其含量在一定范围内增加,且氧化过程中伴随着C6位部分羧基的断裂,DCMCS的结晶度也随之明显下降。DCMCS的氧化度为44%时对纸张的增强效果最大,抗张指数达到14.75N.m/g,相对于空白纸样提高30.53%,其吸湿性随氧化剂用量的增加而减小,保湿性却略有增加。
The carboxymethyl chitosan (CMCS) was selectively oxidatively modified to prepare the dialdehyde carboxymethyl chitosan (DCMCS). The results show that: DCMCS has good moisturizing and paper-reinforcing effect, which can be used as paper enhancements, moisturizing new additives. The structure of the product was characterized by FTIR, XRD and 1 H-NMR. It was confirmed that the aldehyde groups were formed in the C2 and C3 position of carboxymethyl chitosan with the increase of the amount of oxidant, and the content increased in a certain range Oxidation process accompanied by the C6 part of the carboxyl group cleavage, DCMCS also significantly decreased the crystallinity. When the degree of oxidation of DCMCS was 44%, the paper had the strongest enhancement effect on paper, the tensile index reached 14.75Nm / g, increased by 30.53% compared with blank paper, the hygroscopicity of DCMCS decreased with the increase of oxidant dosage, while the moisture retention slightly increased .