Study On The Process And Dangerousness Of Polycaprolactone Polyol Synthesis From Cyclohexanone Peroxide

Polycaprolactone polyol is an organic polymer with excellent biodegradability,good biocompatibility,shape memory temperature control,high crystallinity and low melting point.It can be used in degradable materials,Biomedicine,plastic modification,etc.Using ?-caprolactone as raw material to synthesize polycaprolactone polyols through ring-opening polymerization under different catalyst-initiator systems is a common way to synthesize PCL at present,but there is still a high cost of caprolactone.,There are problems in the production of oligomers in the synthesis,and industrial production and application are difficult.Therefore,this thesis uses cyclohexanone peroxide as the raw material to form polycaprolactone polyols through thermal conversion,esterification,and condensation polymerization,opening a new synthetic route for polycaprolactone polyols.First,using n-butanol as solvent and phosphoric acid as catalyst,the conversion rate of cyclohexanone peroxide under different reaction temperature conditions with or without solvent and with or without catalyst was explored,and the optimal conversion conditions were obtained: reaction temperature 95?,reaction 7h,The conversion rate of cyclohexanone peroxide is 99.2%.Secondly,if the esterification of poly 6-hydroxycaproic acid is to esterify poly 6-hydroxycaproic acid in the way that general carboxylic acid and alcohol react to form ester,the esterification effect is not good,because poly 6-hydroxycaproic acid is prone to alcoholysis or hydrolysis It produces 6-hydroxycaproic acid ester,caprolactone and oligomers,and has a great influence on the esterification rate of poly6-hydroxycaproic acid.Therefore,this subject uses phase transfer theory to neutralize poly 6-hydroxycaproic acid first,and then esterify it,and obtain the best esterification conditions: at 90 ?,18-crown ether-6(poly 6-1% of the mass of hydroxycaproic acid)is used as a catalyst,and 2-bromoethanol is added to react for 2h,and the esterification rate can reach 99.8%.Then,poly 6-hydroxy hexanoate is polycondensed to prepare polycapro lactone polyol.In order to achieve a controllable reaction,we will heat it at 120-170?,the reaction time is 3-6h,poly 6-hydroxy hexanoate: ethylene glycol q uality The ratio is 8:1-12:1,and the catalyst content is within the range of 0.5%-2.5%.Experimental exploration is carried out.Finally,a polycaprolactone po lyol with a molecular weight of 1000-2000 and a dispersibility index of 1.5-1.7 is obtained.Finally,in order to analyze the danger of this route,the DSC test was carried out on cyclohexanone peroxide and polycaprolactone polyol,and a pilot process route was designed,and HAZOP analysis was carried out to analyze the deviation of each equipment and pipe fittings.The situation was discussed,the reasons,consequences and control measures were analyzed,and finally the process flow chart was improved.