Methyl acrylate, heats polymerization

Photolytic. Polymerizes on standing and is accelerated by heat, light, and peroxides (Windholz et al., 1983). Methyl acrylate reacts with OH radicals in the atmosphere (296 K) and aqueous solution at rates of 3.04 x 10 and 2.80 x 10 cmVmolecule-sec, respectively (Wallington et al, 1988b). 

The heat of an emulsion polymerization is the same as that for the corresponding bulk or solution polymerization, since AH is essentially the enthalpy change of the propagation step. Thus, the heats of emulsion polymerization for acrylic acid, methyl acrylate, and methyl methacrylate are —67, —77, and —58 kJ mol-1, respectively [McCurdy and Laidler, 1964], in excellent agreement with the AH values for the corresponding homogeneous polymerizations (Table 3-14). 

These binders possess properties which are very important for ease of manufacture and for obtaining a uniform product. Thus they have low viscosity on casting without sedimentation of solids, have sufficient reactivity for complete low-temperature cure and evolve little heat on polymerization (e.g. much lower than heat of polymerization of methyl acrylate). 

Acidolysis. One method for the preparation of anhydrous acrylic acid is by heating methyl acrylate with 98% formic acid in the presence of a catalytic amount of sulfuric acid and of hydroquinone as polymerization inhibitor. ... 

Transesterificalion. In the conversion of methyl acrylate to n-butyl acrylate, hydroquinone was added as polymerization inhibitor. The mixture was heated at... 

METHYL ACRYLATE (96-33-3) Forms explosive mixture with air (flash point 27°F/-3°C oc). Forms unstable peroxides in storage. Heat above 70°F/21°C, light, and/or lack of appropriate inhibitor concentration can cause explosive polymerization. Elevated temperatures may cause storage containers to explode. Violent reaction with strong oxidizers. Incompatible with strong acids, alkalis, aliphatic amines, alkanolamines. Usually stored in ambient air below 50°F/10°C. The uninhibited monomer vapor may block vents and confined spaces by forming a solid polymer material. 

The vapors of methyl acrylate form explosive mixtures with air, over a relatively wide range the LEL and UEL values are 2.8 and 25.0% by volume in air, respectively. Methyl acrylate undergoes self-polymerization at 25°C (77°F). The polymerization reaction proceeds with evolution of heat and the increased pressure can cause rupture of closed containers. The reaction rate is accelerated by heat, light, or peroxides. Vigorous to violent reaction may occur when mixed with strong oxidizers (especially nitrates and peroxides) and strong alkalies. 

Observe that for monomer concentrations of up to 40%, plots show that first-order kinetics is followed. However, at higher initial monomer concentrations, a sharp increase in rate is observed at an advanced stage of polymerization. At the same time, high-molecular-weight polymers are produced. Autoacceleration is particularly pronounced with methyl methacrylate, methyl acrylate, and acryhc acid. It occurs independent of an initiator and is observed even rmder isothermal conditions. In fact, where there is no effective dissipation of heat, autoacceleration results in a large increase in temperature. 

Low-polydispersity poly(methyl acrylate)-poly(butyl acrylate) block copolymers (PMA-b-PBA) are formed by initially building one block of PMA, replacing MA with BA under vacuum, and heating to 333 K to reinitiate polymerization. The linear increase in the number-average molecular mass (Mji) with conversion and low polydispersity (M IMa= 1.07) demonstrates the formation of a PMA-b-PBA block copolymer (Figure 5.10). 

Methyl acrylate (1.0 mol) is polymerized in benzene (1.0 1 of solution) using succinic acid peroxide (1.0 x 10 mol) at 60°C. How long will it take to convert 10% of the monomer to polymer How long will it take to convert 90% of the monomer to polymer If the polymerization were carried out adiabatically, how much would the temperature have risen after 10% conversion Assume that the specific heat of the benzene solution is 370 cal/°C-l. 

CHi=CMeCOOH. Colourless prisms m.p. 15-16 C, b.p. 160-5 C. Manufactured by treating propanone cyanohydrin with dilute sulphuric acid. Polymerizes when distilled or when heated with hydrochloric acid under pressure, see acrylic acid polymers. Used in the preparation of synthetic acrylate resins the methyl and ethyl esters form important glass-like polymers. 

Monomer and initiator must be soluble in the liquid and the solvent must have the desired chain-transfer characteristics, boiling point (above the temperature necessary to carry out the polymerization and low enough to allow for ready removal if the polymer is recovered by solvent evaporation). The presence of the solvent assists in heat removal and control (as it also does for suspension and emulsion polymerization systems). Polymer yield per reaction volume is lower than for bulk reactions. Also, solvent recovery and removal (from the polymer) is necessary. Many free radical and ionic polymerizations are carried out utilizing solution polymerization including water-soluble polymers prepared in aqueous solution (namely poly(acrylic acid), polyacrylamide, and poly(A-vinylpyrrolidinone). Polystyrene, poly(methyl methacrylate), poly(vinyl chloride), and polybutadiene are prepared from organic solution polymerizations. 

Water (28 g) and polyoxyethylene phenyl ether sulfuric acid ester emulsifier (0.08 g) were added to a 300-ml flask and heated to 85°C while stirring. This solution was then treated with a mixture of the step 4 product (6.3 g), methyl methacrylate (41.6 g), styrene (14 g), butyl acrylate (23.5 g), 2-ethylhexyl acrylate (14.6 g), water (51.6 g), polyoxyethylene phenyl ether sulfuric acid ester emulsifier (6.6 g), and 0.3 g of sodium persulfate over 4 hours. Thereafter, a mixture of water (5.2 g) and ammonium persulfate (0.1 g) were added over 30 minutes and the mixture stirred for an additional 2 hours. It was then cooled to ambient temperature and a white resin isolated, which consisted of 52% solids with a polymerization conversion of 99%. 

Anionic polymerization of (meth)acrylates with hindered ester functions can most likely be conducted at room temperature and above to remove the heat of polymerization with low boiling solvents. Polymerization of the important methyl and ethyl (meth)acrylate members of the family, however, are still plagued by chain termination at higher temperatures. The phosphorus based counterions have a stability advantage over tetraalkylammonium counterions which undergo Hoffman elimination. 

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