摘要
采用以多元羧酸为酯化剂,无机盐为催化剂的交联体系。这一体系是水溶的、无毒害的纤维素交联反应的非甲醛系试剂的交联体系。作者采用傅立叶转换红外光谱(FTIR)分析了多元羧酸与纤维素交联反应过程中催化剂次磷酸盐(NaH2PO2)的作用机理。结果表明:催化剂NaH2PO2对多元羧酸与纤维素酯化反应的两个过程都有催化作用,其两个过程为:1)多元羧酸脱水形成五元环酸酐中间体,NaH2PO2可以降低五元环酸酐中间体形成的温度,加速五元环酸酐的形成;2)五元环酸酐与纤维素亲核取代形成酯,NaH2PO2提高了酯化产物转化率,具有明显的催化作用。
Polycarboxylic acids as esterification agent and inorganic salts as catalyst were used in the research of (cellulose) cross-linking reaction.This soluble cross-linking system is a poison-free and pollution-free system.The mechanism and effect of catalyst NaH_2PO_2 on esterification of cellulose by polycarboxylic acid were studied by FTIR spectra.Experimental results show that NaH_2PO_2 played catalysis role in both stages of esterification between cellulose and polycarboxylic acid,which are:1)The intermediate anhydrides of five-member-ring were formed by dehydration of polycarboxylic acids,during which the formation temperature was reduced by the catalyst;2)Esters were formed through nucleophilic substitution between the five-member-ring anhydride and cellulose during which,the conversion of esterificative products was enhanced by the catalyst.The catalysis effect of NaH_2PO_2 is remarkable.
出处
《林产化学与工业》
EI
CAS
CSCD
2004年第2期43-46,共4页
Chemistry and Industry of Forest Products
基金
国家自然科学基金资助项目(39910594)
关键词
纤维素
多元羧酸
酯化反应
交联反应
次磷酸盐
cellulose
polycarboxylic acids
esterification
cross-linking reaction
NaH_2PO_2
