Polymerization of chlorophenyl glycidyl ethers. VI

Summary Polymerization of p-chlorophenyl glycidyl ether initiated by potassium glycolates (ethylene, propylene and 2-methyl propylene glycolatea) in DMSO containing some 18-crown-6 ether or glycol was investigated. For the reaction system containing the propylene glycolate asymmetrically substituted with a methyl group, relatively high polymerization rates were obtained as compared with those found for the other systems studied, the resultant polymers also having higher molecular weights and comparatively low polydispersities. Aliphatic double bonds were found to be absent in the polymers synthesized, which would suggest that in the anionic polymerization process studied the growing chain is not transferred to the monomer.Dedicated to Prof. C.I. Simionescu on the occasion of the 60th anniversary of his birthday     

Polymerization of bicyclic ethers: 2. N.m.r. structure study of the polymer formed from 3-oxabicyclo[3,2,2]nonane

The polymerization of 3-oxabicyclo[3.2.2] nonane (I) was carried out in methylene chloride with phosphorus pentafluoride and epichlorohydrin at temperatures ranging from ?25° to +25°C. Slow polymerization rates were generally observed, leading to low molecular weight amorphous polymers. By ¹³C n.m.r. and ¹H n.m.r. analysis of the monomer and polymer compounds, it was possible to assign the polymer the structure of a poly(1,4-cyclohexylene-dimethylene there). By comparing the polymer n.m.r. spectra with the proton spectra of two reference compounds, it was possible to establish a microstructure for the repeating unit of the polymer in which the methylenether groups on positions 1 and 4 of the cyclohexane ring are cis to each other. A propagation scheme through oxonium ions is proposed in order to explain the formation of cis polymer.     

Reactions of unsaturated fatty alcohols. II. Polymerization of vinyl ethers and film properties of polymers

Summary Vinyl ethers of stearyl, soybean, and linseed fatty alcohols have been prepared and polymerized in solution in hydrocarbon or chlorinated solvents at temperatures down to −30°C. with several Lewis-acidtype catalysts. Stearyl polyvinyl ether was a white, waxy solid melting at 44°–50°C. while soybean and linseed polyvinyl ethers were colorless, viscous liquids. Molecular weights of these polymers range from 1,500 to 15,000 and higher, depending on the conditions of polymerization. Films of soybean and linseed polyvinyl ethers containing driers were cast from toluene solution. Hard films were obtained with cobalt drier by baking at 150°C. while softer films were obtained under these conditions when lead driers were used. Soybean films containing cobalt drier and baked on Pyrex glass dissolved completely in 5% aqueous alkali. A fatty acid coresponding to the fatty alcohol side chain was isolated from this solution along with a material that appeared to be partially oxidized polyvinyl alcohol. Baked films of soybean polyvinyl ether with lead drier did not dissolve in alkali. Some improvement of alkali resistance was obtained with cobalt films by adding aromatic amines as antioxidants. Soybean polymer films containing cobalt and baked on soft glass or metal surfaces were resistant to 5% aqueous alkali for at least three days. Soybean polyvinyl ether was emulsified with an equal weight of water, using ammonium salts of fatty acids as emulsifiers. Films were prepared from this emulsion that appeared to be continuous. Presented at the meeting of American Oil Chemists' Society, Chicago, Ill., September 24–26, 1956. Since the Department of Agriculture does not recommend the produets of one company over those of another, these names are furnished for information only.     

Reactions of unsaturated fatty alcohols. VII. Polymerization of vinyl ethers catalyzed by stannic and ferric chlorides

Summary Variables affecting the use of stannic chloride as a catalyst for initiating polymerization of conjugated and nonconjugated soybean vinyl ether were studied. Molecular weight of the polymers increased with an increase in catalyst and a decrease in initiation temperature, and it decreased when the amount of moisture in the solvent, the amount of free fatty alcohol in the monomer, or the ratio of solvent to monomer was increased. Aromatic and aliphatic hydrocarbon solvents were superior to halogenated solvents for conducting polymerizations. Similar results were obtained with nonconjugated monomers except that viscosities of the polymers were considerably lower than those of polymers of the same molecular weight obtained from conjugated monomer. To obtain polymers suitable for film-forming studies (4,000–6,000 molecular weight) polymerization is initiated preferably at 25°C. with 3 ml. of anhydrous toluene used per gram of monomer and 4.8 mmoles of stannic chloride per mole of monomer. Monomer purity should be at least 98%. Ferric chloride hexahydrate initiated polymerization at 25°, but polymerization was incomplete, and the polymers had relatively low molecular weights. Presented in part at the fall meeting, American Oil Chemists' Society, Chicago, Ill., Oct. 20–22, 1958. This is a laboratory of the Northern Utilization Research and Development Division, Agricultural Research Service, U. S. Department of Agriculture.     

Radiation-induced cationic polymerization of vinyl ethers in solution: 2. Polymerization of ethyl vinyl ether in methylene dichloride solution

The rates and degrees of polymerization of ethyl vinyl ether (EVE) polymerized by gamma radiation in methylene chloride (CH₂Cl₂) have been studied in detail. The addition of even a small amount of CH₂Cl₂ sharply reduced the rates and degrees of polymerization. After about 0.5 ml_?1 of CH₂Cl₂ the rates became roughly first order in monomer. It is postulated that CH₂Cl₂ strongly solvates the growing chain ends disrupting the solvation by the polymer chains themselves, leading to lower rates. The degrees of polymerization support this hypothesis. Isodielectric constant solutions of EVE in benzene-CH₂Cl₂ mixtures gave rates at the same monomer concentrations, which fitted perfectly those obtained in EVE-CH₂Cl₂ mixtures. These results indicate that the dielectric constant is not the predominating property as formerly thought but that solvation is a more important factor. The activation energies were lower in CH₂Cl₂ solution than in bulk monomer or in low dielectric constant solvents, again indicating perhaps a different state of solvation of the growing chain ends.     

Hybrid copolymerization of alkyl vinyl ethers with glycidyl ethers

Homopolymerization and copolymerization experiments of isobutyl and dodecyl vinyl ether with propylene oxide, and some glycidyl ethers have been carried out by using both conventional cationic initiators (BF₃, BF₃·OEt₂) and 4-chlorophenyldiazonium tetrafluoborate as cationic photoinitiator. Conventional polymerization experiments performed under vacuum at low and room temperature gave rise to a mixture of the two homopolymers, indicating that the epoxide and vinyl ethers are incompatible with respect to chemical reactivity and that apparently no hybrid copolymerization occurs. Analogous results were obtained in parallel photoinitiated polymerization experiments.     

Copolymers of ethylene with bicyclic dienes

The copolymerization of ethylene (E) with dicyclopentadiene (DCP), ethylidene norbornene (ENB) or methyl endomethylene hexahydronaphthalene (MEHN) by ZIEGLER -NATTA catalysts in presence of H₂ affords low-mol.-wt. products over a wide range of unsaturation. In this paper some characteristic features of the copolymerization and some physical properties of the raw products are discussed. For the catalytic system VOCI₃-Al₂Et₃Cl₃ differences in catalyst efficiency, copolymer composition, diene incorporation and viscosity can be seen as a function of type and amount of diene monomer. Physical properties of the copolymers are strongly dependent on composition. Incorporation of dience results in lowered melting points of the parent PE. In case of E-DCP and E-ENB the materials become amorphous beyond 15-20 mole-% diene. At this composition minimum glass transition temperatures are seen.     

冠醚化合物的合成（ⅩⅪⅠ）．内酯型冠醚的合成

合成了１０个内酯型冠醚化合物，其中７个冠醚是新化合物，其结构均由元素分析，及红外、核磁、质谱分析证实。     

微乳液聚合和细乳液聚合

分别从微乳、细乳体系的形成,聚合机理及聚合特点等方断对两者进行了比较,并对各自的应用前景进行了展望。     

Radiation-induced cationic polymerization of vinyl ethers in solution: 4. Polymerization of isopropyl vinyl ether in bulk and in various solvents

The influences of the polymerization media, the monomer and solvent concentrations and the temperature on the radiation-induced polymerization of isopropyl vinyl ether (IPVE) have been studied in detail under super-dry conditions. Rates of polymerization were measured and estimates of the rate constants of polymerization were calculated according to the simplified Hayashi-Williams equation. A comparison of the results with those previously reported for ethyl vinyl ether (EVE) is made. The much higher reactivity of IPVC in low polar solvents is interpreted by a drastic reduction of the polymer intramolecular solvation of the growing chain ends. This is ascribed to the bulkiness of the isopropyl side-chain groups. The radiation-induced polymerization of IPVE in bulk and in various solvents with different physical and solvating properties was studied. This was to obtain further information on the kinetics and the mechanisms involved with this monomer and also the role of the polymerization media. The influence of the monomer and solvent concentrations and of the polymerization temperature on the rate of polymerization have also been investigated.     

双环硝胺类含能化合物的合成进展

综述了国内外双环硝胺类含能化合物的合成进展,主要包括醛胺缩合法合成双环[3.3.1]壬烷衍生物、乌洛托品与亲电试剂反应合成双环[3.3.1]壬烷衍生物、以及含单、双环硝基脲硝胺类含能化合物的合成方法。指出含有单、双环硝基脲的硝胺类含能化合物具有非常高的密度,适合于作为高能量密度材料的基础单元结构;双环[3.3.1]壬烷衍生物合成中的醛胺缩合法为八元双环含能化合物的合成提供了新途径。     

碘代醚类化合物的合成研究

碘代化合物是有机合成化学中的一种重要的中间体.探索了碘代醚类化合物的合成方法.以己二醇为原料,经碘代、成醚,碘化合成了碘代硫醚类化合物,产率达23.5％.以己二醇单碘代中间体为原料,经保护、成醚、脱保护,碘化合成了碘代醚类化合物,产率达30.5％.本合成方法工艺简便、条件温和、原料易得.     

Analysis of disteryl ethers

Disteryl ethers isolated from a vegetable oil and a table margarine were analyzed by capillary gas chromatography. The composition of disteryl ethers in such products reveals whether vegetable oils are mixed with animal fats and if these materials have been subjected to in dustrial bleaching     

表面活性冠醚

综述了表面活性冠醚的结构、合成方法及其在水溶液中的性质。对其在相转移催化、离子选择电极及模拟膜中的应用也进行了简略的讨论。     

Preparation of benzothiophen compounds from bicyclic sulphides

• 1.1. Bicyclic sulphides of 2,3-dihydrobenzothiophen and thiochroman series readily undergo dehydrogenation and dehydro-isomerization to compounds of benzothiophen series in the presence of catalysts with aprotonic acidity (Al₂O₃; 10, 20% ZnCl₂/Al₂O₃). Transformations of thiochroman take place with compression of the six-membered heterocycle.
• 2.2. 20% ZnCl₂/Al₂O₃ is the optimum catalyst for aromatization of compounds of the 2,3-dihydrobenzothiophen series. Yields of benzothiophen compounds from mono-substituted bicyclic sulphides (2- and 3-methyl-2,3-dihydrobenzothiophens) reach 56–72% with a process selectivity of 85–96%. The yield of benzothiophen compounds from a di-substituted bicyclic sulphide (2,2-dimethyl-2,3-dihydrobenzothiophen) exceeds 50% with a process selectivity of 75%.
• 3.3. 10% ZnCl₂/Al₂O₃ is the optimum catalyst in aromatization of thiochroman. Benzothiophen yield exceeds 50% with a process selectivity of 82%.
• 4.4. The proposed catalytic method of obtaining benzothiophen compounds is simple and promising as bicyclic oil sulphides may be used as raw materials for this purpose.

     

敏感冠醚

对各种敏感冠醚的种类及环境变化对冠醚与客体分子或离子的键合能力和选择性的影响进行了评述。     

一种双环原酸酯的合成研究

由原甲酸三乙酯与季戊四醇为原料制备了一种双环原酸酯 4-羟甲基 -2 ,6,7-三氧杂二环( 2 ,2 ,2 )辛烷 ,并提供了一条简单可行的合成途径。     

Origin of bicyclic fatty acids in tall oil

It was shown that two bicyclic fatty acids present in Finnish tall oil were formed from (5Z, 9Z, 12Z)-5, 9, 12-octadecatrienoic acid, pinolenic acid (I). Under the alkaline conditions of sulfate pulping, pinolenic acid forms conjugated isomers which undergo Diels-Alder cyclization during the heating in the tall oil distillation. The cyclization products, here called cyclopinolenic acids, are bicyclic fatty acids and stereoisomers of 4-(5-pentyl-3a, 4,5,7a-tetrahydro-4-indanyl) butanoic acid (IV and V).     

Thermal decomposition of cellulose ethers

The thermostability and thermal decomposition kinetics of methyl cellulose (MC), ethyl cellulose (EC), carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), and hydroxypropyl–methyl cellulose (HPMC) were characterized in nitrogen and air by thermogravimetry (TG). Various methods of kinetic analysis were compared in case of thermal degradation of the five cellulose ethers. The initial decomposition temperature (T_d), temperature at the maximum decomposition rate (T_dm), activation energy (E), decomposition reaction order (n), and pre-exponential factor (Z) of the five cellulose ethers were evaluated from common TG curves and high-resolution TG curves obtained experimentally. The decomposition reactions in nitrogen were found to be of first order for MC, EC, and HPMC with the average E and ln Z values of 135 kJ/mol and 25 min⁻¹, although there were slight differences depending on the analytical methods used. The thermostability of cellulose ethers in air is substantially lower than in nitrogen, and the decomposition mechanism is more complex. The respective average E, n, ln Z values for HEC in nitrogen/air were found to be 105/50 kJ/mol, 2.7/0.5, and 22/8.3 min⁻¹, from constant heating rate TG method. The respective average E, n, and ln Z values for three cellulose ethers (EC/MC/HPMC) in air are 123/144/147 kJ/mol, 2.0/1.8/2.2, 24/28/28 min⁻¹ by using high-resolution TG technique. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 2927–2936, 1999