γ-Ray-induced terpolymerization of carbon monoxide,aziridines, and cyclic ethers

The terpolymerization of carbon monoxide, aziridines, and cyclic ethers was carried out by γ-irradiation. A partially crystalline solid copolymer was obtained. The infrared spectrum of the copolymer obtained indicated characteristic peaks due to the secondary amide and ester groups. The results of elementry analysis, infrared spectra, and x-ray diffraction of the copolymer showed that terpolymerization of carbon monoxide, aziridine, and cyclic ether took place by γ-irradiation. 2-Vinyl-1,3-dioxolane was polymerized in the system of carbon monoxide and ethylenimine to give a solid polymer. The infrared spectrum showed characteristics of the secondary amide and dioxolane ring, while no absorption due to carbonyl group of ester was observed. The infrared spectra and results of elementary analysis confirmed that the terpolymerization of carbon monoxide–ethylenimine–2-vinyl-1,3-dioxolane occurred.     

γ-ray-induced copolymerization of carbon monoxide with cyclic hydrocarbons

The γ-ray-induced copolymerization of carbon monoxide with saturated or unsaturated cyclic hydrocarbons, such as cyclohexane, cyclohexene, 4-vinyl-1-cyclohexene, and cyclopentadiene was studied at 30°C. Resinous or powdery polymers were obtained in the copolymerization. The results of elementary analysis, infrared spectra, and NMR spectra showed that copolymers containing ketone and ring structures were produced. The copolymers were confirmed to be partially crystalline by the x-ray diffraction diagram. Further, the influence of the addition of ethylenimine on the copolymerization of carbon monoxide with cyclohexane or cyclohexene was examined. A powdery polymer formed in the copolymerization was concluded to be a terpolymer of carbon monoxide with cyclic hydrocarbon and ethylenimine. On the basis of the experimental results, a mechanism of the copolymerization is proposed.     

γ-Ray-induced copolymerization of ethylene and vinyl chloride in liquid carbon dioxide

The γ-ray-induced copolymerization of ethylene and vinyl chloride with the use of liquid carbon dioxide as a solvent was studied under a total pressure of 400 kg/cm², with a dose rate of 2.5 × 10⁴ rad/hr at 30°C. A rubberlike, sticky polymer is obtained when the molar concentration of vinyl chloride is less than 30% in the monomer mixture, and the polymer is a white powder at higher concentrations of vinyl chloride. Infrared, x-ray, and differential thermal analyses confirm that the polymerization products are noncrystalline, true random copolymers. The rate of copolymerization decreases markedly when a small amount of vinyl chloride is added to ethylene monomer. In the range of vinyl chloride concentration higher than 5%, however, the rate and the molecular weight of copolymer increase with increasing concentration of vinyl chloride. It has been concluded from kinetic considerations based on these results that the rate of initiation increases proportionally with the concentration of vinyl chloride. Further, the growing chain radicals are shown to be deactivated by the cross-termination reaction between the radicals with terminal unit of ethylene and vinyl chloride, and no transfer reaction occurs.     

Co60 γ-radiation-induced copolymerization of ethylene and carbon monoxide

The γ-radiation-induced free-radical copolymerization of ethylene and CO has been investigated over a wide range of pressure, initial gas composition, radiation intensity, and temperature. At 20°C., concentrations of CO up to 1% retard the polymerization of ethylene. Above this concentration the rate reaches a maximum between 27.5 and 39.2% CO and then decreases. The copolymer composition increases only from 40 to 50% CO when the gas mixture is varied from 5 to 90% CO. A relatively constant reactivity ratio is obtained at 20°C., indicating that CO adds 23.6 times as fast as an ethylene monomer to an ethylene free-radical chain end. For a 50% CO gas mixture, the above value of 23.6 and the copolymerization rate decrease with increasing temperature to 200°C. The kinetic data indicate a temperature-dependent depropagation reaction. Infrared examination of copolymers indicates a polyketone structure containing ? CH₂? CH₂? and ? CO? units. The crystalline melting point increases rapidly from 111 to 242°C., as the CO concentration in the copolymer increases from 27 to 50%. Molecular weight of copolymer formed at 20°C. increased with increasing CO, indicating M?_n values >20,000. Increasing reaction temperature results in decreasing molecular weight. Onset of decomposition for a 50% CO copolymer was measured at ≈250°C.     

Alternative copolymerization of aziridines and carbon monoxide by γ-ray irradiation

The copolymerization of carbon monoxide and aziridines such as ethylenimine and propylenimine was carried out by γ-ray irradiation. Aziridines and carbon monoxide were allowed to copolymerize under γ-ray irradiation from a Co⁶⁰ source and gave a crystalline solid copolymer. The yield of the copolymer increased with reaction temperature. The composition of copolymers obtained did not depend on the feed ratio of monomers and was found to be almost equimolar. The copolymer of ethylenimine and carbon monoxide melted at about 322–335°C. with decomposition and has an infrared spectrum identical with that of poly-β-alanine obtained by the hydrogen-migration polymerization of acrylamide. The hydrolyzed product of the ethylenimine–carbon monoxide copolymer was confirmed to be β-alanine by paper chromatography. These results lead to the conclusion that the copolymerization of aziridines and carbon monoxide took place alternatively by γ-ray irradiation, and produced crystalline poly-β-alanines.     

γ-Ray-induced polymerization of α-haloacrylic acids

The γ-ray induced polymerizations of α-chloroacrylic acid, mp 66°C, and α-bromo-acrylic acid, mp 72°C, were investigated in the temperature range from 35°C to 85°C. An analysis of polymerization kinetics was made, and results were similar to those reported in the literature for other vinyl monomers. On heating of the polymer obtained, elimination of hydrogen halide takes place, and intramolecular lactone formation is observed. The rate of lactone formation of poly(α-chloroacrylic acid) obtained in the solid-state polymerization was found to be higher than that in the liquid state, because a highly isotactic configuration of polymers, tends to be formed in the solid-state polymerization, and elimination of hydrogen chloride is facilitated with an isotactic 5₂ helix structure.     

Influence of addition of ethylene on the γ-ray-induced alternating copolymerization of ethylenimine and carbon monoxide

The influence of the addition of ethylene on the γ-ray-induced alternating copolymerization of ethylenimine and carbon monoxide was investigated. A mixture of ethylenimine, carbon monoxide, and ethylene was irradiated to produce a polymer containing these monomeric units. The infrared spectrum of the copolymer showed the characteristic absorption peaks of the secondary amide and ketone bond and was different from that of the reaction product of polyketone with ethylenimine and that of the γ-ray irradiation product of ethylene and poly-ß-alanine. The x-ray diffraction diagram of the copolymer was different from those of poly-ß-alanine and polyketone and exhibited an amorphous structure. Paper chromatographic analysis showed that the hydrolysis product of the copolymer contained ß-alanine and δ-aminovaleric acid. These results indicate that terpolymerization of ethylenimine, carbon monoxide, and ethylene took place under γ-ray irradiation and gave an amorphous polymer containing the units \documentclass{article}\pagestyle{empty}\begin{document}$ \rlap{} ({\rm CH}_{\rm 2} {\rm CH}_{\rm 2} {\rm NHCO}\rlap{}),\rlap{} ({\rm CH}_{\rm 2} {\rm CH}_{\rm 2} {\rm CO}\rlap{}),{\rm and}\rlap{} ({\rm CH}_{\rm 2} {\rm CH}_{\rm 2} {\rm CH}_{\rm 2} {\rm CH}_{\rm 2} {\rm NHCO}\rlap{}) $\end{document}     

Ring-opening copolymerization of α-chloromethyl-α-methyl-β-propionolactone with ε-caprolactone

α-Chloromethyl-α-methyl-β-propionolactone (CMMPL) has been copolymerized with ε-caprolactone (CL) using a wide range of feed compositions and aluminium triisopropoxide [Al(OⁱPr)₃] as an initiator. Random copolymers of CMMPL with CL were obtained. The pendant chloromethyl groups of the copolymer were converted to quaternary ammonium salts by reaction with pyridine, resulting in an increased hydrophilicity of the copolymers.     

A direct synthesis of α-keto five- and six-membered cyclic ethers

A simple synthesis of tetrahydro-2H-pyran-2-yl and tetrahydrofuran-2-yl ketones from their corresponding carboxylic acids was studied. A comparison was made of organolithium and Grignard alkylating reagents as a means of reducing the formation of byproducts and improving the yields.     

Alternating copolymerization of fluoroalkenes with carbon monoxide

The palladium-catalyzed alternating copolymerization of fluoroalkenes, represented as CH(2)=CH-CH(2)-C(n)F(2n+1), with CO was performed using (R,S)-BINAPHOS (2e) as a ligand. The CH(2)-C(n)F(2n+1) group is the most electronegative substituent ever reported for the copolymerization (Taft's sigma value of 0.90 for CH(2)CF(3)). The copolymer obtained from CH(2)=CH-CH(2)-C(8)F(17) (1a) existed as a mixture of polyspiroketal and polyketone, while that from CH(2)=CH-CH(2)-C(4)F(9) (1b) was a pure polyspiroketal, as was revealed by infrared and (13)C-CP/MAS NMR spectroscopies. The terminal structure of the polymer from 1b was confirmed by MALDI-TOF MS spectrometry. Detailed NMR studies suggested that the much higher reactivity with (R,S)-BINAPHOS (2e) than that with the conventional ligand DPPP (2a) can be attributed to the unique 1,2-insertion of the fluoroalkene into acylpalladium species. The existence of an electronegative substituent on the alpha-carbon of the palladium center is successfully avoided in the 1,2-insertion mechanism.     

Alternating copolymerization of dienes with α-olefins

Alternating copolymerization of butadiene with several α-olefins and of isoprene with propylene were investigated by using a mixture of VO(Acac)₂, Et₃Al, and Et₂AlCl as catalyst. The alternating copolymerization ability of the olefins decreases in the order, propylene > 1-butene > 4-methyl-1-pentene > 3-methyl-1-butene. The study on the sequence of the copolymer of isoprene with propylene by ozonolysis reveals that the polymer chain is reasonably expressed by the sequence \documentclass{article}\pagestyle{empty}\begin{document}$ \rlap{--} [{\rm CH}_{\rm 2} \hbox{--} {\rm CH} \hbox{=\hskip-1pt=} {\rm C(CH}_{\rm 3}) \hbox{--} {\rm CH}_{\rm 2} \hbox{--} {\rm CH(CH}_{\rm 3}) \hbox{--} {\rm CH}_{\rm 2} \rlap{--}]_n $\end{document}. NMR and infrared spectra indicate that the chain is terminated with propylene unit, forming a structure of ?C(CH₃)? CH₂? C(CH₃)?CH₂ involving a vinylene group.     

Influence of addition of olefins on the alternating copolymerization of carbon monoxide and ethylenimine by azobisisobutyronitrile or by γ-ray irradiation

The alternating copolymerization of carbon monoxide and ethylenimine to give poly-β-alanine could be initiated by γ-irradiation but hardly by α,α'-azobisisobutyronitrile (AIBN). It was found that in the case of the addition of olefin, this system could be copolymerized even by AIBN and that, in the γ-ray copolymerization of carbon monoxide and ethylenimine, the addition of olefin brought about an increase in the copolymer yield. No difference was observed between the nature of copolymers obtained by AIBN and those obtained by γ-irradiation, except in the system carbon monoxide–ethylenimine–ethylene. An increase in the amount of reacted olefin gave rise to an increase in copolymer yield. The melting points of the copolymers were in the range 295–335°C. The infrared spectra, x-ray diffraction diagrams, and NMR spectra of the copolymers were almost identical with that of poly-β-alanine obtained by the hydrogen-migration polymerization of acrylamide. Paper chromatographic analysis of the hydrolysis product of the copolymer showed the existence of β-alanine, ethylamine, and δ-aminovaleric acid homolog in the products. From these results, it was concluded that terpolymerization of carbon monoxide, ethylenimine, and olefin took place in the presence of AIBN or γ-irradiation which gave a crystalline solid copolymer containing the units of nylon 3 and nylon 5. A mechanism of this copolymerization was proposed on the basis of these results.     

Radical-initiated homo- and copolymerization of α-methylene-γ-butyrolactone

The kinetics of α-methylene-γ-butyrolactone (α-MBL) homopolymerization was investigated in N,N-dimethylformamide (DMF) with azobis(isobutyronitrile) as initiator. The rate of polymerization (R_p) was expresed by R_p = k[AIBN]^0.54[α-MBL]^1.1 and the overall activation energy was calculated as 76.1 kJ/mol. Kinetic constants for α-MBL polymerization were obtained as follows: k_p/k_t^1/2 = 0.161 L^1/2 mol^?1/2·s^?1/2; 2fk_d = 2.18 × 10^?5 s^?1. The relative reactivity ratios of α-MBL(M₂) copolymerization with styrene (r₁ = 0.14, r₂ = 0.87) were obtained. Applying the Q–e scheme led to Q = 2.2 and e = 0.65. These Q and e values for α-MBL are higher than those for MMA     

Selenium-Catalyzed debromination of vic-dibromoalkanes and α-bromo ketones with carbon monoxide and water

Selenium has been found to be an excellent catalyst for the reductive debromination of some organic bromides with carbon monoxide and water: vic-dibromoalkanes and α-halo ketones can be reduced to the corresponding alkenes and ketones respectively in moderate to high yields.     

Emulsion copolymerization behavior of α-methylstyrene with methacrylonitrile

The emulsion copolymerization behavior of α-methylstyrene with methacrylonitrile is described. The effects of polymerization temperature, potassium persulfate initiator concentration, sodium lauryl sulfate emulsifier concentration on copolymer yield, molecular weight, and rate of copolymerization are described. The copolymer was found to have an azeotropic composition at 43 mole-% AMS. Reactivity ratios were determined to be 0.06 and 0.28 for AMS and MAN, respectively.     

Regiocontrolled copolymerization of methyl acrylate with carbon monoxide

An alternating copolymer of methyl acrylate with carbon monoxide has been synthesized for the first time via coordination polymerization using palladium complexes of phosphine-sulfonic acid as catalysts. The highly controlled head-to-tail structure of the copolymer was confirmed by NMR spectra. Subsequent insertion of carbon monoxide and methyl acrylate to methylpalladium species provided gamma-ketoalkylpalladium 2. The present system apparently conquered the difficulty in coordination-insertion of CO to 2.     

Polymerization and copolymerization of α-methacrylophenone

Under a variety of conditions it has not been possible to induce the free-radical-initiated homopolymerization of α-methacrylophenone (α-MAP). The only product isolated from such efforts was the Diels-Alder dimer of the monomer. A Mayo-Lewis plot of the free-radical copolymerization of α-MAP and styrene shows considerable scatter but the copolymer composition indicates that an α-MAP unit can add to itself. These results have been ascribed to a penultimate effect. α-MAP is homopolymerized by dimsylsodium or n-butyllithium. Attempted copolymerization of α-map and styrene with n-butyllithium produces >95% α-MAP. Unexpectedly, α-MAP does not homopolymerize with lithium dispersion, but does react in the presence of styrene to give product containing a relatively small amount of α-MAP.