甲壳素类液晶高分子的研究 Ⅰ侧基长度对羧酰化甲壳素的液晶性的影响  

STUDIES ON CHITIN- BASED LIQUID CRYSTALLINE POLYMERSⅠ INFLUENCE OF SIDE CHAIN LENGTH ON THE LIQUID CRYSTALLINE BEHAVIOR OF ACYLATED CHITIN

作　　者：董炎明[1] 汪剑炜[1] 吴智福 梅雪峰[1] 袁清[1] 刘晃南 

机构地区：[1]厦门大学材料科学系,厦门361005

出　　处：《高分子学报》1999年第5期576-580,共5页Acta Polymerica Sinica

基　　金：中国科学院纤维素化学开放研究实验室资助

摘　　要：四种羧酰化甲壳素即乙酰化、丙酰化、丁酰化和己酰化甲壳素在二氯乙酸溶液中均呈现胆甾型溶致液晶相．临界浓度随侧基长度增加而略有增加，衍生物的临界浓度明显都比原甲壳素高许多，这些规律都可以用链刚性的变化来解释．四种羧酰化甲壳素在剪切时均能形成条带织构，而且能形成条带织构的最低浓度有明显差别，随侧基长度增加而提高，进一步表明侧基较长，液晶性减少．Methanesulfonic acid method was used to prepare five acylated chitins. Exceptheptanoyl chitin , four of them ,i.e .acetyl chitin ,propionyl chitin ,butyryl chitin andhexanoyl chitin ,had high degree of substitution(from 1 5 to 2 0)and exhibited lyotropicliquid crystalline behavior and cholesteric phase . Asthelength oftheside chain increased thecritical concentration ( W/ W)somewhat increased from 0 21 to 0 26 because the chainrigidity dropped . The criticalconcentration valuesofallthefour derivatives were much higherthan that of chitin(0 12) due to the decrease of intramolecular hydrogen bonds. The fouracylated chitin can form typical banded texture after being sheared . There minimumconcentrations to form banded texture of them were evidently different,varied from 0 25(for acetylchitin)to 0 37 (for hexanoyl chitin) . These results further indicated that liquidcrystallinity decreased while thelength offlexible side substituentsincreased .

关 键 词：液晶性 甲壳素 羧酰化甲壳素 合成 溶致液晶 

分 类 号：O636.1[理学—高分子化学] O753.2[理学—化学]