別甾基甲酸 的英文怎麼說
中文拼音 [biézāijījiǎsuān]
別甾基甲酸
英文
allo-etianic acid-
Abstract : methanesulfonic acid method was used to prepare five acylated chitins. except heptanoyl chitin, four of them, i. e. acetyl chitin, propionyl chitin, butyryl chitin and hexanoyl chitin, had high degree of substitution ( from 1. 5 to 2. 0 ) and exhibited lyotropic liquid crystalline behavior and cholesteric phase. as the length of the side chain increased the critical concentration ( w / w ) somewhat increased from 0. 21 to 0. 26 because the chain rigidity dropped. the critical concentration values of all the four derivatives were much higher than that of chitin ( 0. 12 ) due to the decrease of intramolecular hydrogen bonds. the four acylated chitin can form typical banded texture after being sheared. there minimum concentrations to form banded texture of them were evidently different, varied from 0. 25 ( for acetyl chitin ) to 0. 37 ( for hexanoyl chitin ). these results further indicated that liquid crystallinity decreased while the length of flexible side substituents increased
文摘:四種羧酰化甲殼素即乙酰化、丙酰化、丁酰化和己酰化甲殼素在二氯乙酸溶液中均呈現膽甾型溶致液晶相.臨界濃度隨側基長度增加而略有增加，衍生物的臨界濃度明顯都比原甲殼素高許多，這些規律都可以用鏈剛性的變化來解釋.四種羧酰化甲殼素在剪切時均能形成條帶織構，而且能形成條帶織構的最低濃度有明顯差別，隨側基長度增加而提高，進一步表明側基較長，液晶性減少A super acylation catalyst, 4 - dimethylamino pyridine ( dmap ), was prepared and used to synthesize cholesteryl ester compounds. four kinds of cholesteryl ester compounds such as cholesteryl p - alkoxyl benzoate, cholesteryl dicarboxylate, cholesteryl lumequeic ester and coattail - like cholesteryl ester were synthesized by acylation method and super acylation catalyst method. chemical structures and liquid crystal behaviors of the synthesized samples have been characterized by using element analysis, ftir, dsc and polarized microscopy with a hot stage
本文合成了高效酰化催化劑4 -二甲基氨基吡啶（ 4 - dimethylaminopyridine ， dmap ） ，採用酰氯化法和高效酰化催化劑法分別合成了對烷氧基苯甲酸膽甾醇酯、對稱脂族二羧酸膽甾醇酯、烯酸膽甾醇酯及燕尾型膽甾醇酯四類膽甾醇酯衍生物，並進行了化學結構和液晶性能的表徵。
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