| Ammonium nitrate plays an important role in industry,agriculture and national defense,but its polycrystallinity limits its application.The purpose of this thesis is to restrain its phase transition and improve the usability of ammonium nitrate.Using ammonium persulfate and sodium bisulfate as redox initiator,acrylic potassium slat polymer and acrylic sodium salt polymer which had good mobility were synthesized via aqueous polymerization. Both the two polymers were added to ammonium nitrate to prepare stabilized ammonium nitrate which were characterized by DSC,SEM and XRD.The experimental results showed that acrylic potassium salt polymer could stabilize ammonium nitrate.When the addition was more than 2.0%,acrylic potassium salt polymers which molecular weight were between 1×103 and 1×105 could preventⅣ-Ⅲphase transition and raise the temperature up to 100℃.That was because the crystal phase of stabilized ammonium nitrate transferred to phaseⅢat room temperature.Acrylic sodium salt polymer couldn't stabilize ammonium nitrate.When the addition was between 1.0%and 2.0%,the phase transition behavior of stabilized ammonium nitrate were the same as pure ammonium nitrate.When the addition was more than 2.0%,acrylic sodium salt polymers which molecular weight were between 1×103 and 1×105 caused a new phase transition peak on 89℃and the melting peaks were reduced forward,but there were stillⅣ-Ⅲphase transitions peak on 50℃.That was because the crystal phase didn't transfer but still stabilized in phaseⅣat room temperature.Compared the two polymers,acrylic potassium salt polymer which contained potassium cation had better effect on stabilizing ammonium nitrate.The same conclusion was made when compared potassium salts to sodium salts.There were two effects when used acrylic potassium salt polymer as crystal phase stabilizer,one was potassium cation replacing NH4+ in ammonium nitrate and the other was polymer coating ammounim nitrate on the surface.
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