Allyl acetate solution polymerization

Very much as in the case of vinyl acetate, the solution polymerization of allyl acetate in benzene leads to the addition of the growing radical chains to benzene to produce stable aromatic adducts with a tendency to terminate by combination. This explains the retention of the degree of polymerization in the expected range (DP = 14.3-14.9) and the fact that a polymer chain may contain more than one aromatic group [14]. 

The preceding indicates that in bulk and in benzene solution, the polymerization of allyl acetate leads to polymers of relatively low molecular weight. It had been expected that in emulsion processes, a higher-molecular-weight polymer would be formed. However, with a persulfate initiator, the emulsion polymerization of this monomer led to a product with the same molecular weight as was found upon bulk polymerization [18]. 

The polymerization of allyl acetate has been studied reasonably extensively in the effort to elucidate the mechanisms of the polymerization process. The utility of poly(allyl acetate) as a resin is believed to be negligible. Nevertheless, this compound has been polymerized in bulk, in solution, and in emulsion. There is mention of a cationic polymerization process and of radiation-induced charge-transfer processes. 

The solution polymerization of allyl acetate was studied in an effort to determine the effect of monomer concentrations on the reaction kinetics [14]. These studies were limited to the use of benzene. The growing allyl acetate radicals formed stable adducts with the solvent much as vinyl acetate does. The stabilized adduct is terminated by combination with a growing radical. The twinning reaction is said to account for the relatively high molecular weight of the polymer despite the fact that the reaction with benzene is a chain-transfer reaction. Ethyl acetate, on the other hand, would have been a preferable solvent... 

In Experiment 1, 9.28 moles of allyl acetate per liter of latex was emulsified with 0.087 mole of sodium lauryl sulfate, buffered with 0.45 mole of sodium pyrophosphate, and initiated with 0.0920 mole/liter of potassium persulfate. In experiment 2, again 9.28 moles of allyl acetate per liter of latex was polymerized in the presence of 0.087 mole of sodium lauryl sulfate, 0.45 mole of sodium pyrophosphate, and 0.366 mole/liter of potassium persulfate. Since the MW of allyl acetate is 100, the above information implies that the basic monomer to water ratio is an unlikely 928 gm of monomer to approximately 70 gm of water. If indeed these are the experimental facts, then the fact that the polymers produced resembled those produced in bulk or in solution is not surprising. A reaction mixture consisting of nearly 93% pure monomer, naturally would be expected to produce a polymer similar to one produced from a pure (i.e., bulk) monomer and not one similar to an emulsion polymer. Compositions of less than 60% monomer in water would ordinarily be expected to produce latices. Perhaps the data in question refer to a ratio of 9.28 moles of monomer to one liter of water. 

One patent reports the use of a seed -polymerization technique to produce an allyl acetate-ethyl acrylate copolymer [. In a typical example, to 305 gm of a 3.28% solution of poly(vinyl alcohol) (DP 1000) is added 10 gm of allyl acetate and 0.8 gm of potassium persulfate. The mixture is heated to 75°C followed by the addition of 190 gm of ethyl acrylate with heating for 2.25 hr at 80°-85°C. After stirring for an additional hour and cooling to room temperature, the resultant latex is claimed to exhibit 99.6% conversion of all of the monomer to polymer. The pH of the latex is said to be 2.5. 

Cationic polymerizations of allyl esters require further investigation. Schild-knecht [7] mentions the polymerization of allyl acetate and of allyl formate in benzene solution upon heating the solution with 6% of benzenediazonium fluoroborate under nitrogen at 200°C in sealed tubes. The solid products melt at about 190°C (d) and are soluble in benzene and insoluble in methanol. 

Using azobisisobutyronitrile (AIBN) initiator, benzene solvent, and a polymerization temperature of 60°C, others confirmed the alternation copolymerization of MA with allyl acetate.Alternating copolymers were obtained with reduced viscosities of 0.11-0.19 dl/g, measured for 0.2% solutions of copolymer in iV,AT-dimethylformamide at 30°C. Equimolar allyl benzoate-MA copolymer, which has had very little study, may also be easily obtained with peroxide initiators. 

Photo-oxidation of citronellol in polystyrene beads [120]. A sample of 3.0 g of polystyrene beads (commercial, cross-polymerized with 1% of divinylbenzene) was treated with a solution of 2 mg of tetraphenylporphyrin and 780 mg (5 mmol) of citronellol in 20 mL of ethyl acetate in a petri-dish (30 cm diameter). After 2h in a ventilated hood, the solvent has evaporated and the petri-dish was covered with a glass plate and irradiated for 5 h with a 150 W halogen lamp. The solid support was then washed with 3 x 20 mL of ethanol, the combined ethanol fractions were rota-evaporated and 900 mg of the hydroperoxide mixture (96%) was isolated as a slightly yellow oil. The hydroperoxides were quantitatively reduced to the corresponding allylic alcohols by treatment with sodium sulfite. One of these products is used in the industrial synthesis of rose oxide. 

Electroreduction of pyridazines in the presence of acetic anhydride gives the acylated open-chain diamines (cf. 117 -> 222). In aqueous solution a 1,2-dihydropyridazine is formed, which decomposes to nitrogen and an unsaturated hydrazino-aldehyde that polymerizes. Allylic bromi-nation of l,2-dicarbomethoxy-l,2,3,6-tetrahydropyridazine followed by de-hydrobromination gives l,2-dicarbomethoxy-l,2-dihydropyridazine. Catalytic hydrogenation gives the hexahydro compound." ... 

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