LLM-105在二甲基亚砜中的结晶介稳区研究

Crystallization Metastable Zone of LLM-105 in Dimethyl Sulfoxide

为改善2,6-二氨基-3,5-二硝基吡嗪-1-氧化物(LLM-105)的晶体形貌,控制LLM-105的晶体粒度,利用CrystalSCAN多通道结晶仪,采用浊度法测定了LLM-105在二甲基亚砜(DMSO)中的介稳区宽度。研究了初始浓度、搅拌速率和降温速率对介稳区宽度的影响。根据经典成核理论,计算了受降温速率影响的成核级数。结果表明,在降温结晶过程中,LLM-105在DMSO中的介稳区宽度随初始浓度,搅拌速度的增加而变窄,随着降温速率的增加而变宽。得到的最佳结晶条件为:初始浓度0.0700 g·mL^(-1),搅拌速率390 r·min^(-1),降温速率1.0℃·min^(-1)。当初始浓度从0.0670 g·mL^(-1)增至0.0750 g·mL^(-1)时成核级数从1.825升高到2.5747。在最佳结晶条件下,添加2.5 g粒度为4μm的LLM-105晶种于DMSO-LLM-105溶液中,可获得表面光滑、形貌规则、粒度(60μm)可控的高品质LLM-105柱状颗粒。

To improve the crystal morphology of 2,6-diamino-3,5-dinitropyrazine-1-oxide（LLM-105） and control the crystal size distribution of LLM-105 , the metastable zone width of LLM-105 in dimethyl sulfoxide（DMSO） was measured by turbidity method using a CrystalSCAN multi channel crystallization instrument. The effects of initial concentration, stirring speed and cooling rate on the metastable zone width were studied. The nucleation orders effected by cooling rate were calculated based on the classical nucleation theory. Results show that in the cooling crystallization process, the metastable zone width of LLM-105 in DMSO narrows with increasing the initial concentration and stirring speed. The metastable zone width broadens with increasing the cooling rate. The optimal crystallization conditions obtained are initial concentration of 0.0700 g·mL^-1, stir speed of 390 r·min^-1 cooling rate of 1.0 ℃·min^-1. The nucleation order increases from 1.825 to 2.5747 when the initial concentration increases from 0.0670 g·mL^-1 to 0.0750 g·mL^-1. Under the optimal crysallization conditions, the controllable high quality LLM-105 columnar particles with smooth surface , ruly morphology and particle size of 60 μm are obtained by adding the 2.5 g LLM-105 crystal seed with particle size of 4 μm into DMSO-LLM-105 solution.