Study On The Reaction Behavior And Risk Of Hydroge Peroxide And Cyclohexanone

Under low temperature and acidic conditions,cyclohexanone was oxidized with hydrogen peroxide at a concentration of 28.5%,and cyclohexanone peroxide was obtained after water washing,neutralization,suction filtration and drying,and characterize it by 1H NMR,13 C NMR,IR,and GPC,combined with some phenomena during the experiment,it can be found that the cyclohexanone peroxide obtained in the experiment is a polymer,the weight average molecular weight was 7646,the number average molecular weight was 4721,and the molecular structure formula was obtained,the molecular junction of which contains a peroxy bond,and hydrogen peroxide is attached to the polymer by intermolecular force.The effects of the molar ratio of hydrogen peroxide to cyclohexanone?the reaction time?and the stirring rate on the conversion of cyclohexanone and the yield of cyclohexanone peroxide were studied,the results show that under the optimal conditions,that is,n(hydrogen peroxide): n(cyclohexanone)= 1.5: 1,the reaction time was 3 h,stirring rate was 240 rad / min,and the conversion and yield can reach 98.2% and 96.4%,respectively.Cyclohexanone peroxide contains peroxy bonds and was attached with hydrogen peroxide,so its properties are unstable,and self-accelerated decomposition was extremely easy to occur,in the thermal runaway state,a large amount of heat was released,resulting in high pressure,and cause fire and explosion accident.Differential scanning calorimetry(DSC)was used to test the thermal decomposition characteristicsof the product,and the curves of the heat flow with temperature at different heating rates were obtained,the curves were numerically simulated and the conversion rate was calculated to calculate the initial exothermic temperature and decomposition heat,then,perform kinetic analysis on its thermal stability test data to obtain the temperature TD24 and the adiabatic temperature rise ?Tad.The results showed that the initial exothermic temperature of the product cyclohexanone peroxide was around 90?,the heat of decomposition was about 1371.938 J / g,TD24 = 30.7?,and the adiabatic temperature rise ?Tad = 762.2?,which was very dangerous.In order to improve the safety of cyclohexanone peroxide in the actual production,packaging,transportation and use,the thermal stability can be effectively improved by adding stabilizers,the results showed that the initial exothermic temperature of cyclohexanone peroxide was increased after adding the mixed stabilizer sodium silicate ? disodium EDT and amagnesium sulfate(Addition of mixed stabilizer accounts for 0.5% of the total mass of the system,the ratio is 1: 1),the exothermic temperature was 610.251 J / g,TD24 was 82.5?,and ?Tad was 183.7?.The obtained cyclohexanone peroxide can be converted into poly6-hydroxyhexanoic acid under higher temperature and catalytic conditions,and the conversion products are characterized by 1H NMR,13 C NMR,IR,GPC.The conversion effect of cyclohexanone peroxide under no-catalysis conditions and two systems of t-butanol as the solvent,titanium sieve as the catalyst and propionic acid as the solvent,boric acid as the catalyst were studied,It has been found that in the absence of a catalyst,the conversion of cyclohexanone peroxide was poor,the conversion effect of cyclohexanone peroxide in the propionic acid-boric acid system was slightly better than that in the tert-butanol-titanium silicon molecular sieve system,and the effects of reaction temperature,amount of catalyst and pH value in the reaction system on the conversion effect were discussed.The results show that in the non-catalytic conditions,the optimal reaction temperature was 100 ?,and the conversion rate was 78.7%.In the propionic acid-boric acid system,the optimal reaction conditions are reaction temperature was 100?,catalyst content accounts for1.8% of total system mass,and the conversion rate is 99.8%.In the tert-butanol-titanium silicon molecular sieve system,the optimal reaction conditions are reaction temperature was 100?,catalyst content accounts for 2.2% of total system mass and the pH of the system was 10,under these conditions,the conversion rate was97.5%.