A modified Reppe process for manufacturing acrylic acid (AA) under normal pressure and another method by hydrolysis of acrylonitrile (AN) are reported. I. Modified Reppe process using normal pressure under continous operation.Thier reaction is affected by various factors such as molar ratio, acetylene feeding velocity, reaction temperature, circulation velocity, viz, agitating velocity and so on.The best reaction conditions were as follows : Acetylene feeding velocity : 200 l/hr.Reaction temperature : 40°CCirculation velocity for the reaction mixture : 1, 800 l/hr.Reaction composition : AA/Solvent=1/1 (wt.) Solvents : MEK, MIBKThe yield was about 80%.II. AN hydrolysisThe follwing reactions for conversion of AN into AA were studied.CH2=CHCN+H2SO4+H2O→CH2=CHCONH2·H2SO4CH2=CHCONH2·H2SO4 +H2O→CH2=CHCOOH + NH4HSO41. The first step reaction (formation of acrylamide).AN/sulfuric acid/water=1/1.5/4 (molar ratio) was employed at 12°C for 5 hrs with strring.The yield was about 95%.2. The second step reaction (formation of AA) The hydrolysis of acrylamide was effected by using 6 mol suplementary water per mol of acrylamide at 100°C for 2 hrs with stirring.Over-all yield of AA was about 850.3. KineticsThe apparent activation energy for the hydrolysis of AN was about 11.3 kcal/mol and the reaction was found to be second order in the concentrations of AN and water.

Isobutyl acrylate (IBA) and cyclohexyl acrylate (CHA) were synthesized through a modified Reppe process using normal pressure, ester-exchange reaction between methyl acrylate (MA) and iso-butyl alcohol or cyclohexyl alcohol and also through direct esterification of acrylic acid (AA) with alcohols.1. Modified Reppe process using normal pressure under continuous operation.This reaction is affected by various factors such as molar ratio, acetylene feeding velocity, reaction temperature, circulation velocity, viz, agitating velocity and so on.The best reaction conditions were as follows : a) IBAAcetylene feeding velocity : 200 /hr.Reaction temperature : 40°CCirculation velocity for the reaction mixture : 1, 800 /hr.Reaction composition : IBA/i-BuOH=3040/7060 (wt.) The yield was about 75% and the purity of IBA was 97.597 80%.b) CHAAcetylene feeding velocity : 150 /hrReaction temperature : 40°CCirculation velocity for the reaction mixture : 1, 500 /hrReaction composition : CHA/HOH= 5070/5030 (wt.) The yield was about 75% and the purity of CHA was 97.297 60%.2. Ester-exchange reaction of MA with i-BuOH or HOH.MA/acohol molar ratio of 1.52/1 was employed below 110°C for 5 hrs with stirring. The yield of IBA and CHA was 95 and 85%, respectively.The apparent activation energy for the ester-exrchange reaction between MA and i-BuOH or HOH was 13.3, 16.3 kcal/mol respectively and the reaction was second order in the concentrations of MA and an alcohol.3. Esterification of AA with i-BuOH or HOH.The esterification of AA in the presence of sulfuric acid was tested. AA/alcohol/organic solvent= 1/1. 2/0.8 (molar ratio) was employed below 110°C for 5 hrs with stirring.The yield of IBA and CHA was 96 and 89%, respectively.The apparent activation energy for the esterification between AA and i-BuOH was found to be 15.9 kcal/mol and the reaction was second order in the concentration of AA.

Various alkoxycarbonylmethyl acrylates have been prepared by a unique method.Monochloroacetate and sodium acrylate or sodium methacrylate have been let to react in the presence of triethylamine as the catalyst at 100110°C in 38 hrs.The alkali-resistance of these esters is inferior to that of ethyl acrylate (EA), but the acid resistance is as good as that of EA.In the case of copolymerization between ethoxycarbonylmethyl acrylate (M1) and styrene (M2), r1 is 0.08±0.02 and r2 is 0.68±0.03. Q1 and e1 were 0.38 and 0.91 respectively.

As clarified in our previous paper, the formation of nickel carbonyls is affected by various factors, such as reaction temperature, reaction pressure, reaction time, molar concentration of ammonium chloride in the raw materials, and so forth.The reaction is effected through the carbonylation reaction between nickel complexes and carbon monoxide at high temperatures and high pressures. However, due to the extremely poor solubility of Ni(NH3)6Cl2 complex in water, the continuous synthesis is not quite efficient.Additional studies were therefore made in a more systematic manner, and some of the findings have been reported.

Methyl acrylate is cony erted quantitatively to methyl α, β-dichloropropionate by chlorination at room temperature in the presence of 4 mol-% DMF as the catalyst.Methyl α, β-dichloropropionate is then methoxylated by reaction with an equimolar amount of Na-methylate in one hour without a catalyst at -20 to -35°C in mately 90% yield.Methyl α-chloro-β-methoxypropionate is let to react with an equimolar amount of potassiumcyanide at 30°C in a homogeneous solution. The yield is about 95%, but part of the produced α-cyano-β-methoxy propionate changes into poly-α-cyanoacrylate. Therefore, the true cyanation yield appears to be between 60 to 70%.Then crude methyl α-cyano-β-methoxypropionate is converted to methyl α-cyanoacrylate at rather high temperature, since the reaction involves the degradation of poly-α-cyanoacrylate. The reaction is carried out at 170250°C/39mmHg in a SO2 stream in the presence of 3 mole-% sulfuric acid and 100 g of DOP. Approximately 80% yield is attained.

Radical and anionic polymerization of alkyl α-cyanoacrylates have been studied using BPO and DMF as an initiator.1. Radical polymerization.Solution polymerization in nitromethane was 1/2 order in concentration of BPO and 1st order in concentration of the monomer.The activation energies of the polymerization were calculated to be as follows : for methyl ester, 22.9 ; ethyl ester, 20.1; isopropyl ester, 18.8 ; n-butyl ester, 20.6 ; isobutyl ester, 20.1; and 2-ethylhexyl ester, 20.9 kcal/mol. On the other hand, the activation energies in bulk polymerization were found to be as follows : for methyl ester, 22.2; and ethyl ester, 20.4 kcal/mol.The interrelationships among Rp, monomer concentration, and initiator concentration at 67°C were shown as follows : Rp 2.21 × 10-4 (BPO) 1/2 (CNM) Rp=2.44×10-4 (BPO) 1/2. (CNE) where(BPO) : the initial concentration of BPO (mol/l) (CNM) : the initial concentration of methyl α-cyanoacrylate (mol/l) (CNE) : the initial concentration of ethyl α-cyanoacrylate (mol/l) Copolymers with methyl acrylate, methyl methacrylate, or styrene were characterized by the alternating and azeotropic nature.2. Anionic polymerization.Solution polymerization in nitromethane was 2 nd order in concentration of DMF and 1st order in concentration of the monomer. The activation energies of the polymerization were calculated to be as follows : for methyl ester, 9.9; ethyl ester, 8.6; isopropyl ester, 7.4; n-butyl ester, 7.6; isobutyl ester, 7.9; and 2-ethylhexyl ester, 8.0 kcal/mol.The interrelationships among Rp, monomer concentration, and initiator concentration at 50°C were shown as follows : Rp =2.94 × 10-5 (DMF) 2. (CNE) where(DMF) : the initial concentration of DMF (mol/l) (CNE) : the initial concentration of ethyl α-cyanoacrylate (mol/l)

Various methods have been suggested for the preparation of ethyl acrylate.In the present study, acrylic acid was esterified using ethyl sulfate to form ethyl acrylate. Thus, a mixture of acrylic acid, ethyl sulfate, and water (1/1. 54/2, mol) mol was heated at 70°C for 2 hrs. The conversion was 88%and the yield was 75% based on the acrylic acid used.

Direct syntheses of alkyl acrylates from acrylic acid and olefins have been studied.Thus, tert-butyl acrylate was obtained in 73% yield upon treatment of 1 mol acrylic acid with 1.1 mol isobutylene in ethylene dichloride in the presence of 0.05 mol sulfuric acid at 20°C., for 4 hrs under 2 atm pressure.Similarly, cyclohexyl acrylate was obtained in 80% yield upon treatment of 1 mol acrylic acid with 1.2 mol cyclohexene in ethylene dichloride in the presence of 0.05 mol sulfuric acid at 140°C., for 5 hrs under 40 atm pressure. The apparent activation energy was 18.4 kcal/mol and the reaction was first order in cyclohexene concentration.