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.     

Radical-initiated copolymerization of carbon monoxide and ethylenimine in the presence of ethylene

The radical-initiated copolymerization of carbon monoxide and ethylenimine in the presence of ethylene was studied quantitatively. Carbon monoxide copolymerized with difficulty with ethylenimine with α,α′-azobisisobutyronitrile as radical initiator. In the presence of a small amount of ethylene, however, a remarkable amount of crystalline powdery poly-β-alanine (nylon 3) was obtained. The crystalline copolymer, which mainly consists of nylon 3 and contains a small amount of nylon 5 and other substances of higher homologous nylon structure, was obtained in the presence of a large amount of ethylene. This copolymer scarcely contained any ketone structure. Increasing the total feed of the equimolar mixture of the monomers increased the conversion of total monomer and nylon 3 content in the copolymer formed. The effect of increasing carbon monoxide content in this system was to increase both the conversion and the nylon 3 content in the copolymer. In both cases the copolymers were almost identical with nylon 3. Increased ethylene content in the monomer feed, however, increased the conversion and the content of higher homologous nylon structures, such as nylon 5 and 7. From the results it was concluded that ethylene was involved not only in the propagation reaction but also particularly in the initiation reaction.     

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.     

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}     

γ-Ray-induced copolymerization of carbon monoxide with cyclic ethers

The γ-ray copolymerization of carbon monoxide with cyclic ethers, such as ethylene oxide, phenyl glycidyl ether, 1,3-dioxolane, 2-vinyl-1,3-dioxolane, terahydrofuran, 1,4-dioxane, and acetaldehyde was studied. A yellowish or brownish powdery copolymer was obtained in most of the cases examined. The infrared spectra showed that copolymers containing the ester structural unit were produced in the copolymerization with cyclic ethers which have no vinyl groups, and that a copolymer containing a ketone structure was produced from cyclic ether having vinyl group. It was found that the copolymer with ethylene oxide also had a β-propiolactone ring structure at the chain end or the side chain. The copolymers were confirmed to be partially crystalline from the x-ray diffraction diagrams. Further, a ring-opening polymerizability of the cyclic ether by γ-radiation was discussed. And it was found that as the bond dissociation energy between the carbon–oxygen linkage of the cyclic ether is small, the polymer yield both in the homopolymerization and copolymerization with carbon monoxide is high. A mechanism for the copolymerization is proposed on the basis of the results.     

Preparation of crystalline polyamides by the alternating copolymerization of aziridines and cyclic imides

The copolymerization of aziridines and cyclic imides was studied. Aziridines copolymerized alternately with cyclic imides to give crystalline polyamides. Ethylenimine and succinimide copolymerized to nylon 2,4, melting near 300°C., without any catalyst. Similarly, the corresponding crystalline polyamides were obtained from the systems of 1,2-propylenimine–succinimide, ethylenimine–glutarimide, and ethylenimine–phthalimide. The copolymerization of aziridines and cyclic imides in the presence of BF₃OEt₂ gave a copolymer which was rich in aziridine units, whereas, the addition of triethylamine had no influence on the copolymer composition. A mechanism of copolymerization was proposed based on the facts that N-tetramethylenesuccinamide was obtained by the reaction of pyrrolidine and succinimide, N-acetylethylenimine reacted with acetamide to yield N,N′-diacetylethylenediamine and that the rate of this copolymerization was dependent on the electrophilicity of imide.     

Block polymers from isocyanate-terminated intermediates. II. Preparation of butadiene–ϵ-caprolactam and styrene–ϵ-caprolactam block polymers

Polystyrene–nylon 6 and polybutadiene–nylon 6 block copolymers have been prepared from isocyanate-terminated prepolymers. From extraction and fractionation data the products obtained were found to be mixtures of both homopolymers and pure block copolymer. The polybutadiene–nylon 6 copolymers are extremely pliable at ambient temperatures even at high ?-caprolactam contents (70–80 wt-%). This is true even though these copolymers show a crystalline melting point at 213°C similar to poly-?-caprolactam. Presumably this unusual behavior occurs because of the nature of the synthesis which renders the butadiene portion of these copolymers the continuous phase. Plasticity measurements indicate that pliability is dependent on the molecular weight of the block poly-?-caprolactam.     

γ- and ultraviolet-radiation-induced solid-state polymerization of maleimide in a few binary systems

The solid-state polymerization of maleimide by γ- and ultraviolet irradiation was carried out in binary systems with succinimide, maleic anhydride, and acenaphthylene. Polymaleimide obtained from the solid-state polymerization of maleimide by γ-rays was amorphous, while that obtained from the solid-state polymerization by ultraviolet rays was highly crystalline. In the maleimide–succinimide system the rate of polymerization reached a maximum nearly at the eutectic composition when the polymerization was carried out by γ-irradiation. With ultraviolet irradiation the rate of polymerization became higher with increasing content of succinimide in the feed. In the maleimide–maleic anhydride system a copolymer of both constituents was formed by γ-irradiation, but almost no homopolymer was produced. On the other hand, two kinds of polymers, a crystalline copolymer and an amorphous one, were produced by ultraviolet irradiation. The results were compared with those obtained from the copolymerization in solution. In the maleimide-acenaphthylene system the main products with ultraviolet irradiation was the dimer of acenaphthylene.     

Ligand‐Dependent Diastereoselectivity in the Palladium‐Catalyzed Copolymerization of Styrene with Carbon Monoxide

[(LL′)Pd(H₂O)](OTf)₂ complexes, in which LL′ is a chelate ligand containing the chiral 4‐benzyl‐4,5‐dihydrooxazole moiety and either pyridin‐2‐yl or 2‐(diphenylphosphino)phenyl substituents, catalyze the copolymerization of styrene with carbon monoxide with an isotactic or prevailingly syndiotactic microstructure, respectively. The chiroptical properties of the copolymers and model studies for carbon monoxide and olefin insertion on related Pd complexes suggest that the reason for the different stereochemistry of the copolymers is a site‐selective coordination of the olefin in the intermediates containing the PN ligand; a lower regioselectivity in the coordination and a different coordination site lead to the different diastereoselectivity for the copolymer formation by the complex containing the NN′‐ligand.     

Energy characteristics of poly(olefin ketone) surfaces at different interfaces

The energy characteristics of surfaces of new polymers belonging to the class of poly(olefin ketone)s at the interfaces with air and polar (water) and nonpolar (octane) liquids were determined by the ?ontact angle method. The objects of the study were binary copolymer (propyl-ene—carbon monoxide, PCO) and ternary copolymers (propylene—carbon monoxide—ethyl-ene—carbon monoxide, PECO; but-1-ene—carbon monoxide—ethylene—carbon monoxide, BECO). It was shown that the ternary copolymers can be recommended for further medicobio-logical tests as a base for the development of hemocompatible materials. The equilibrium values of the interfacial energy of poly(olefin ketone)s at the interfaces with water and octane make it possible to predict their adhesion properties for designing composite materials.     

New routes for copolymerization of carbon monoxide with styrene or vinyl chloride and photodegradation of these copolymers in solutions

New routes for copolymerization of carbon monoxide with styrene or vinyl chloride were found by emulsion polymerization (nonionic or ionic emulsifier). These procedures yielded copolymers containing carbonyl groups even at high conversion. These carbonyl-containing polyketones were photoirradiated in solvent. In carbon monoxide—styrene copolymer of high molecular weight, the viscosity change produced by photoirradiation was especially remarkable, while in carbon monoxide—vinyl chloride copolymer no pronounced change in viscosity was observed, even at high contents of carbonyl group.     

Use of carbon suboxide to obtain block and graft copolymers. II. Grafting of carbon suboxide on polyethylene

Experiments have been carried out on grating of carbon suboxide on nonactivated polyethylene films and on films previously activated by ultraviolet irradiation and by γ-irradiation. The experiments gave a grafted copolymer. A grafted copolymer was also obtained on grafting carbon suboxide in solution on polyethylene films preactivated by means of ozonization at 70°C. Examination of the copolymer indicated its structure to be cross linked. It has been proved that below 50°C single molecules of carbon suboxide react with polyethylene. The polyethylene thus modified is then easily surfacedyed.     

Alternating copolymerization of carbonyl sulfide with aziridines

The copolymerization of carbonyl sulfide with aziridines such as ethylenimine, propylenimine, and N-ethylethylenimine was studied in various organic solvents. The copolymerizations occurred easily without the addition of any catalyst and gave white powdery crystalline copolymers. The copolymers produced were insoluble in many organic solvents, but soluble in p-chlorophenol and dimethyl sulfoxide. The elementary analyses and the infrared spectra showed that alternating copolymers which have a thiourethane structure were produced. In the copolymerization of carbonyl sulfide with ethylenimine, both the polymer yield and the molecular weight of the resulting polymer increased with the use of a solvent having a higher dielectric constant, and also with an increase in the ratio of carbonyl sulfide to imine in the feed. The rate of copolymerization of carbonyl sulfide with aziridines was in the order of ethylenimine > propylenimine > and N-ethylethylenimine. Irradiation of the copolymers improved their thermal properties and increased their melting point.     

Novel sol–gel methodology to produce LaCoO3 by acrylamide polymerization assisted by γ-irradiation

In this paper we report the synthesis of LaCoO₃ (LCO) nano-particles with two methodologies: the conventional sol–gel reaction of acrylamide (AA) polymerization using a cross-linking agent (methylenebisacrylamide or MBA) with the activation of the polymerization reaction by thermo-chemical initiator (azobisisobutyrnitrile or AIBN). The second was a novel sol–gel methodology in which the polymerization of AA monomers was done without MBA and the initiation was achieved by gamma radiation. With thermochemical initiator a xerogel with a foam and porous structure was obtained, while the gamma-irradiation of the mixture leads to the formation of a compact resin with entrapped cations. X-ray diffraction (XRD) shows that formation of the product begins around 500 °C and according to analysis of microscopy images of powders calcined in 700 °C the average sizes of particles are 20 nm and 42 nm for samples obtained using γ-irradiation and AIBN as initiators, respectively. TEM images also show differences in particle morphology. Those synthesized using AIBN as initiator are dispersed, while those with γ-irradiation are in aggregates.     

Radiation-induced cryocopolymerization of hydrogen cyanide and epichlorohydrin: Copolymerization traveling waves initiated by mechanical fracture at 77 K

Low-temperature (77–150 K) radiation-induced copolymerization of hydrogen cyanide (HCN) and epichlorohydrin (ECH) has been studied. Copolymers have been obtained in two modes of running the reaction, the thermally activated postpolymerization at slow heating of the preliminarily γ-irradiated system and the traveling wave of copolymerization initiated by local brittle fracture of solid samples at 77 K. The threshold values of parameters (a dose of preliminary irradiation, comonomer ratio in the initial mixture) necessary for the realization of the self-sustained wave mode of copolymerization have been determined. An increase in the HCN concentration in the initial comonomer mixture suppresses the copolymerization, and the yield of the copolymer decreases. Epichlorohydrin-soluble copolymers with the content of HCN units up to 5.7 mol % have been obtained as the result of the process.     

Copolymerization of carbon disulfide and N-(β-cyanoethyl)ethylenimine

It was found that carbon disulfide copolymerizes with N-(β-cyanoethyl) ethylenimine by using water as a catalyst. The copolymerization was conducted in detail by using water as a catalyst in the temperature range between 0 and 50°C with various initial concentrations of carbon disulfide and N-(β-cyanoethyl)ethylenimine in the absence of solvent. The copolymer obtained was always composed of the two monomers: 1:1 ratio, independent of the initial concentration of the monomers. The copolymer was white solid material soluble in dimethyl sulfoxide, insoluble in other usual organic solvents and decomposed at 155°C. Spectroscopic analysis of the copolymer combined with the results of elemental analysis indicates that the copolymer had the following structure:      

手性钯(Ⅱ)配合物及BF3·Et2O助剂催化的丙烯与一氧化碳立体选择性交替共聚反应研究

BF3·Et2O助催化剂加速了[L2]Pd (OAC)2(L:手性双瞵配体)催化的丙烯与一氧化碳立体选择性交替共聚反应,在相对较短的时间里合成了手性聚酮高分子,13C NMR和1H NMR,及摩尔旋光度证实产物具有较高的区域规整度和立构规整度,红外光谱指出产物同时具有螺旋缩酮和交替聚酮结构,凝胶渗透色谱法测定产物具有较低的分子量和宽的聚合度。     

Regio- and stereocontrol in the alternating copolymerization of olefins with carbon monoxide

Strictly alternating copolymers between olefins and carbon monoxide are synthesized using cationic palladium catalysts modified by phosphorus or nitrogen ligands. Basic chelate diphosphines as the ligand allow the regioregular copolymerization of aliphatic olefins thus affording, e.g. in the case of propene, poly(1-oxo-2-methyltrimethylene). Steric control of the copolymerization process towards the production of overwhelmingly isotactic copolymers is possible particularly when using atropisomeric ligands. In the case of styrene as the substrate and for all ligands employed the copolymerization process is regioregular. Prevailing syndiotactic structure is obtained with 1,10-phenanthroline or 2,2′-bipyridine as the ligand. Chelate thioether ligands allow the preparation of a completely atactic material. For 4-tert-butylstyrene an isotactic structure became accessible by using chiral bisoxazolidines. The prevailing structure of the copolymers of cyclopentene corresponds to a 1,3-enchainment of the olefin units most probably associated with a prevailing diisotactic structure     

Costereosymmetric α-olefin copolymers

Copolymerization of propylene and 1-butene with highly stereospecific three-component coordination catalysts produced multiblock crystalline copolymers having stereo-regular sequences of both propylene and 1-butene. Copolymers containing from 3 to about 80% 1-butene had two DTA melting points which were attributable to polypropylene and poly-1-butene crystallinity. Those containing from 18 to about 70% 1-butene had x-ray diffraction patterns showing peaks characteristic of polypropylene and form I poly-1-butene, but form II poly-1-butene crystallinity was never observed. The multiblock copolymer structure observed is also supported by the fact that the product of the reactivity ratios is greater than unity. The composition distributions of low-conversion and continuously prepared copolymers were similar and relatively broad. For example, copolymers containing an average of 12% 1-butene had species containing from 5–30% 1-butene. High-conversion copolymers had an even broader composition distribution due to the gradual increase of the 1-butene concentration in the comonomer mixture as the copolymerization proceeded. The absence of homopolymers was demonstrated by fractionation. The ability to detect homopolymers was proved by the fact that a mixture of stereoregular polypropylene and poly-1-butene were readily separated. Increasing the amount of 1-butene tended to decrease those properties dependent upon crystallinity such as hardness, tensile strength, stiffness, density, and melting point, but tended to improve significantly the impact strength, low temperature properties, and clarity of molded objects. These duocrystalline copolymers retained a much higher level of properties than that observed for random copolymers prepared with less stereospecific coordination catalysts.