摘要
通过木薯淀粉与 3-氯-2-羟丙基三甲基氯化铵及三聚磷酸钠、磷酸二氢钠/磷酸氢二钠,在不同反应介质、不同酸碱性条件下合成的对比实验,以及三聚磷酸钠在水和水-乙醇反应介质中的各自性质变化测定分析,研究了同时进行阴、阳离子化反应磷酸型两性淀粉一步合成的机理。结果表明:在碱性的水-乙醇介质中,三聚磷酸钠水解可被有效抑制,而以酸酐结构的分子状态存在;用三聚磷酸钠作为阴离子化反应试剂一步合成磷酸型两性淀粉,反应过程中三聚磷酸钠保持酸酐结构、阳离子基团上存在负氧离子是同时引入季铵型阳离子、磷酸型阴离子的关键。
The comparing experiments for synthesizing PAS in which cassava starch reacted with 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHPTAC), sodium tripolyphosphate (STP) or sodium biphosphate/disodium hydrogen phosphate in different reaction media and at acid or alkali condition were designed. By measuring the electric conductivity of sodium tripolyphosphate, the hydrolysis behavior of sodium tripolyphosphate in the media of water or water/ethanol was analyzed, respectively. The synthesis mechanism of PAS in process of simultaneous cationization and phosphrylation was also investigated. The results show that in the alkaline water/ethanol media, hydrolysis of STP can be restrained effectively and most STP still keeps molecular state of acid anhydride structure, this is one of the key factors of successfully introducing anionic group of phosphate in starch by the simultaneous process of cationization and phosphrylation, and another key factor is that on the side chain of the cationic group exist several groups which can be changed into active electronegative oxygen ions. While cassava starch reacts with CHPTAC by cationization, the electronegative oxygen ion of the cationic group undergoes nucleophilic reaction with STP, and produces phosphate anionic derivative.
出处
《高校化学工程学报》
EI
CAS
CSCD
北大核心
2005年第1期42-47,共6页
Journal of Chemical Engineering of Chinese Universities
基金
教育部优秀青年教师资助计划项目(教人司[2002]40 号)
广西大学校管基金。
