本文選題：硝酸銨 + 表面活性劑　； 參考：《南京理工大學》2017年碩士論文

【摘要】：本文以工業(yè)品硝酸銨顆粒為原料,A和B混合溶劑為介質,設計的十八酸為包覆劑,采用吸附包覆的方法,得到十八酸吸附包覆硝酸銨顆粒的最佳包覆工藝條件和包覆樣品,來達到降低硝銨鹽顆粒吸濕性的目的。首先,選擇僅含C、H、O、N的4種不同極性基團及其不同脂肪烴鏈長的表面活性劑作為包覆材料,以吸濕率降幅和包覆層質量分數(shù)為指標,考察不同原料樣品準備的實驗操作和環(huán)境條件對硝酸銨吸濕性的影響用于改進包覆工藝條件,進而初步比較不同表面活性劑包覆硝酸銨降低其吸濕性的效果,篩選出防吸濕性效果最好的表面活性劑作為下階段實驗所需的包覆材料。其次,展開全面包覆工藝優(yōu)化實驗,通過初步探索實驗,考察所選表面活性劑投加量、溶劑配比、反應溫度、反應時間等因素對包覆效果的影響,得到較佳工藝條件范圍。進而,對上述各因素進行工藝優(yōu)化實驗和工藝條件因素的影響實驗,研究得到以十八酸為包覆劑的最佳工藝條件和各因素對硝酸銨顆粒吸濕率降幅和包覆層質量分數(shù)的影響規(guī)律。最后,將上述得到的最佳工藝條件進行工藝為20g/批放大實驗,對得到的最佳包覆樣進行SEM和FTIR表征。結果表明,經溶劑除水和冷卻方式工藝方式改進,包覆樣吸濕率降幅提高3%-5%。吸附包覆實驗研究所得最佳包覆工藝為,以十八酸為包覆材料,以5.0g硝酸銨為原材料,投加量為2.00g,在混合溶劑中攪拌進行表面吸附包覆。其中,A和B溶劑體積配比為15mL:15mL,反應溫度55℃,反應時間1.5h,自然冷卻6h后出料,減壓抽濾所得包覆樣品并干燥。取5.0g包覆樣品在溫度35℃,相對濕度68%條件下吸濕24h,得到吸濕率降幅為34.4%,包覆層質量分數(shù)為0.76%。最佳工藝條件按等比例放大到20g/批,經放大工藝所得的20g包覆樣品,在溫度35℃,相對濕度92%條件下吸濕24h,得到吸濕率降幅29.7%,包覆層質量分數(shù)為1.01%。上述兩個量級的實驗結果,包覆的硝酸銨的吸濕率降幅超過目前同類文獻報道的最高值。SEM表征發(fā)現(xiàn)改性后的樣品表面變得致密光滑,表面孔洞和裂紋減少;FTIR表征可知表面活性劑吸附包覆在顆粒表面。本文在已有文獻基礎上通過改進包覆工藝方法和條件,使包覆改性后的硝酸銨顆粒防吸濕效果明顯提高,可為硝酸銨防吸濕包覆工藝的進一步研究和其它硝銨鹽改性研究提供一定的實驗基礎。
[Abstract]:In this paper, using ammonium nitrate particles as raw materials and octadecanoic acid as coating agent, the optimum coating conditions and coating samples of ammonium nitrate particles adsorbed by octadecanoic acid were obtained. To reduce the hygroscopicity of ammonium nitrate particles. Firstly, four kinds of surfactants with different polarity groups and different fatty hydrocarbon chain lengths were selected as coating materials. The decrease of moisture absorption rate and the mass fraction of coating layer were taken as indexes. The effects of the preparation of different raw materials and the environmental conditions on the moisture absorption of ammonium nitrate were investigated in order to improve the coating conditions, and to compare the effect of different surfactants coated with ammonium nitrate on the hygroscopicity of ammonium nitrate. The best anti-moisture absorbent surfactant was selected as the coating material for the next stage of the experiment. Secondly, the optimization experiment of comprehensive coating process was carried out, and the effects of the dosage of surfactant, the proportion of solvent, reaction temperature and reaction time on the coating effect were investigated, and the better technological conditions were obtained. Furthermore, the process optimization experiments and the effects of technological conditions on the above factors are carried out. The optimum process conditions of octadecanoic acid as coating agent and the influence of various factors on the decrease of moisture absorption rate of ammonium nitrate particles and the mass fraction of coating layer were obtained. Finally, the optimal process conditions were obtained by 20g/ batch amplification experiment, and the optimal coating samples were characterized by SEM and FTIR. The results show that the decrease of moisture absorption rate of the coated sample is increased by 3%-5% through the improvement of solvent dewatering and cooling process. The optimum coating technology was obtained by adsorption coating experiment. The coating was prepared by mixing octadecanoic acid as coating material, ammonium nitrate as raw material and adding amount of 2.00g in mixed solvent. The solvent volume ratio is 15ml: 15mL, the reaction temperature is 55 鈩，

本文編號：1794951