pH值对邻苯二亚胺纤维素的制备及荧光性能的影响

Effect of the pH on the Synthesis of o-Phenylenediimido Cellulose and its Fluorescence Behavior

制备了席夫碱（Ｓｃｈｉｆ’ｓｂａｓｅ）邻苯二亚胺纤维素（ＰＤＩＭＣ），考查ｐＨ值对制备反应和产物荧光性能的影响。结果表明：氧化度为１００％的二醛纤维素在ｐＨ＝７～１３、室温下、反应３０ｈ生成的邻苯二亚胺纤维素，具有较强的荧光性能，熔点为４１０Ｋ，分解温度为５７８Ｋ；ＰＤＩＭＣ水溶液在ｐＨ＝７．６，浓度为７．６×１０－４ｇ／ｍＬ，２０℃时，Ｅｘ＝４７０ｎｍ，Ｅｍ＝５５５ｎｍ处荧光最强。

A new polymer, Schiff's base o-phenylenediimido cellulose (PDIMC), was synthesized. PDIMC displays the fluorescence emission at 555 nm with the execiting wavelength at 470 nm at room temprature. The effect of pH on the reaction and fluorescence behavior of the Schiff's base has been studied. When the pH is in the range of 7～13, PDIMC is the main product, especially in neutral solution (pH=7.6) fluorescence intensity of the system shows the strongest emission at 555nm. With increasing the pH, polymerization of o-phenylenediamine and crosslinking reaction of dialdehyde cellulose with o-phenylenediamine accelerated, and the fluorescence intensity of system decreased.