微胶囊技术在硝酸铵改性中的应用

提出了用聚苯乙烯包覆硝酸铵制备硝酸铵微胶囊的新方法 ,采用电子能谱仪研究了包覆效果 ,并对包覆前后的硝酸铵进行吸湿性测量 ,分析了改性后的硝酸铵吸湿结块性降低的原因和机理。     

酰胺型表面改性剂的合成及对硝酸铵吸湿性的研究

硝酸铵在工农业以及国防业有着举足轻重的地位,然而它本身具有的易吸湿性和结块性限制了它在很多方面的应用,而含有氨基的表面改性剂却又是硝酸铵改性中应用效果较好的一类改性物质,主要因为氨基不仅能和硝酸铵形成氢键或者静电作用,更能够与硝酸铵反应形成化学键,后者包覆改性效果更显著。     

微胶囊对无机盐的改性研究

利用物理化学原理进行相分离，利用壁材凝聚包覆的物理化学方法，对硝酸铵进行包覆，使硝酸铵的吸湿性和结块性得到改善；对产物进行分析，得到产物与硝酸铵的性质对比数据；并讨论了影响产物质量的因素。实验结果表明：利用微胶囊技术对硝酸铵进行改性，在一定条件下是可行的，并达到了缓释的目的。     

用超临界流体反溶剂过程改性包覆硝酸铵

为了降低硝酸铵(AN)的吸湿性并提高其流散性,采用超临界流体反溶剂过程对其表面进行改性包覆,以硝化棉为包覆材料、丙酮为共溶剂、超临界CO2为反溶剂,研究了体系温度、压力和萃取速率对包覆效果的影响.对包覆后样品的吸湿性进行了测定和SEM分析.结果表明,体系温度是影响包覆效果的最     

聚乙烯醇缩丁醛包覆硝酸铵的性能研究

采用液相分离技术,用聚惭烯醇缩丁醛（PVB）对硝酸铵（AN）进行包覆。研究了包覆后硝酸铵的性能,并对包覆的效果进行了表征。结果表明,用PVB包覆AN,包覆效果较好,产品的吸湿性、结块性都有大幅度下降,Ⅱ→Ⅲ的晶型转变吸收峰移向高温甚至消失。     

改性铵油炸药研究

通过对普通硝酸铵进行改性制得一种多微孔改性硝酸铵,并对其物理性能和爆炸性能进行了深入研究。研究结果表明,改性铵油炸药具有较低的吸湿性和结块性,吸油性好,不渗油,是一种爆轰感度高、爆炸性能优良的新型工业炸药。     

硝酸铵的结块与防止

硝酸铵的吸湿性、多晶性造成了硝酸铵的结块。分析了影响松散型硝酸铵松散度降低并结块的主要原因是水分、造粒颗粒度、温度、松散添加剂、添加剂添加量、包装方式和储存条件,提出了提高硝酸铵松散度的具体改进措施。对防止硝酸铵结块的几种途径进行了讨论,介绍了防结块剂的应用情况,并介绍了五种硝酸铵专用防结块剂的特点及其应用情况。     

提高松散型硝酸铵成品松散度的措施

硝酸铵的吸湿性、多晶性造成了硝酸铵的结块。文章分析了在湿度较大的情况下，影响松散型硝酸铵松散度降低并结块的主要原因有水分、造粒颗粒度、温度、松散添加剂、添加剂添加量、包装方式和储存条件，并在此基础上提出了提高硝酸铵松散度的具体改进措施。     

表面活性剂改善硝酸铵吸湿性研究

用表面活性剂对硝酸铵进行表面改性处理 ,测定了改性硝酸铵的吸湿性。结果表明 ,表面活性剂能有效地降低硝酸铵的吸湿率 ,改性硝酸铵的吸湿率比普通硝酸铵降低约 30 % ,并得出了较为理想的硝酸铵改性表面活性剂。     

虫胶包覆硝酸铵工艺研究

利用物理化学包覆的相分离原理,以虫胶为包覆剂、正丁醇为溶剂、正己烷为沉淀剂包覆硝酸铵,降低其吸湿性,用硝酸铵的吸湿率表征包覆效果。对正丁醇与正己烷配比、混合溶剂用量、沉淀剂滴加速度、虫胶用量等影响吸湿性的因素进行了研究。结果表明,正丁醇与正己烷体积比为1:3,混合溶剂与硝酸按配比为5.0 mL/g,沉淀剂滴加速度为6s/滴,虫胶用量与粒径成反比。在较佳包覆条件下,虫胶包覆硝酸铵可使吸湿率下降55%。     

包覆硝酸铵发射药吸湿性和安定性研究

为研究包覆硝酸铵(AN)发射药的吸湿问题,用硝化棉(NC)对不同AN含量的AN发射药进行了不同层数的包覆,然后对未包覆和包覆试样进行了平衡干燥器法吸湿测试和真空安定性试验。结果表明:在温度为30℃、相对湿度为90%的条件下,AN发射药的吸湿量随着AN含量的增加而增加;包覆层有效抑制了吸湿性,提高了AN发射药的安定性。     

乙二胺反应型包覆硝酸铵及其在叠氮聚醚推进剂中的应用

为改善含相稳定硝酸铵(PSAN)推进剂的力学性能,用乙二胺与PSAN颗粒表面反应,制备了乙二胺反应型包覆PSAN。FTIR证实乙二胺与AN之间发生了化学反应。通过吸湿性、接触角测量,对包覆效果进行了表征。结果表明,包覆后PSAN的表面极性明显降低,吸湿性也有一定程度改善。将包覆后的PSAN应用到BAMO-THF推进剂中,发现乙二胺包覆量为0.2%时对推进剂力学性能的改善效果最好,σm提高约46%,εm提高约83%。     

Effect of polymer coating on ammonium nitrate substrate

Prilled, spheroidized, and granular ammonium nitrates (AN) were coated with poly(chloro-p-xylylene) (parylene C) by a vapor deposition polymerization technique. Particles of AN with a 0.2% coating remain free flowing after long exposure to ambient conditions. The effectiveness of the coating as a moisture barrier on the three forms of AN was found to be in the order spheroids > prills > granules. Water adsorption isotherms and hygroscopicity determinations indicate that a 0.7% coating hydrophobes the surface of AN by approximately one order of magnitude. The parylene C/AN interface exhibits chemical and physical stability at elevated temperatures.     

硝酸铵的吸湿性研究

介绍了硝酸铵的吸湿机理,防止硝酸铵吸湿的手段以及吸湿性和包覆效果的表征方法,并对防止硝酸铵吸湿的各种手段进行分析。     

Effect of carrier agents on physicochemical properties of foam-mat freeze-dried date powder

Date powder was produced by foam-mat freeze-dried method without and with carrier agents (maltodextrin and gum arabic) at two concentration levels (40 and 50%). The effect of carrier agents on the physicochemical properties of powder, i.e., hygroscopicity, degree of caking, wettability, dispersibility, solubility, water absorption index, color, and total phenolic content was investigated. Carrier agent-added date powders had lower hygroscopicity that offers good storage stability. Maltodextrin-added powders had lower wettability and higher solubility which indicate good reconstitution properties. The hygroscopicity, degree of caking, wettability, and total phenolic content significantly decreased with an increase in carrier concentration level.     

Quality control measures for developing of 10:20:20 grade fertilizer

It has been shown by agronomists that N.P.K. 10:20:20 is the most suitable fertilizer grade for Pakistan soils to produce high tobacco yields.An attempt was made to manufacture this grade on the pilot scale. Field experiments were conducted for the study of its agronomic efficiency. Physical Quality control measures for the study of its keeping quality were carried out. These studies included hygroscopicity, hardness, caking tendency etc. along with other parameters keeping in view the climatic conditions. No evidence of general superiority was found between the indigenous grade and the imported one.     

Physical Evaluation and Hygroscopic Behavior of Dragon Fruit (Hylocereus undatus) Lyophilized Pulp Powder

Relations between moisture content and water activity of foodstuff can be estimated by determining moisture sorption isotherms. This work aimed at investigating the hygroscopic behavior of dragon fruit powder through sorption isotherms, encapsulated with maltodextrin, and analyzing hygroscopicity, density, and caking degree of samples stored in polyethylene wrappings and laminated coverings at 25°C. Dragon fruit powder showed good results regarding hygroscopicity, density, and caking degree for laminated coverings. In order to describe balance of sorption isotherms, the BET model was the most recommended.