摘要:

AbstractTerpolymerizations of polar vinyl monomers, acrylonitrile, methyl acrylate, or methyl methacrylate with butadiene and styrene in the presence of ethylaluminium dichloride, zinc chloride, or other Lewis acids were carried out. The yield and the contents in monomer units of the terpolymer and the yields of the polar vinyl monomer/butadiene 1,4‐cycloaddition byproduct formed in these systems were determined. Butadiene conversions in the above terpolymerizations and 1,4‐cycloaddition side reactions were related to those in the copolymerization and 1,4‐cycloaddition proceeding in corresponding binary systems without styrene. The results are discussed in terms of a radical polymerization and a polar 1,4‐cycloaddition mec

ISSN:0025-116X    

DOI:10.1002/macp.1977.021780701

出版商:Hüthig&Wepf Verlag    

年代:1977

数据来源: WILEY

摘要:

AbstractRadical polymerizations of acrylonitrile, methacrylonitrile, methyl acrylate, and methyl methacrylate in the presence of Lewis acid type complexing agents like ZnCl2, SnCl4, or (C2H5)nAlCl3−n(n = 1,2,3) were investigated. The accelerating or inhibiting effects of the complexing agents on the polymerization of individual monomers were observed depending on the concentration and the character of the complexing agent. These effects were found to be also influenced by the monomer structure. The polymerization mechanism is discusse

ISSN:0025-116X    

DOI:10.1002/macp.1977.021780702

出版商:Hüthig&Wepf Verlag    

年代:1977

数据来源: WILEY

摘要:

AbstractThe diimide of metal‐[2,9or10(or 2,16or17)bis(3,4‐dicarboxybenzoyl)]phthalocyanine(diPc) (where i = imide)2or3were prepared from 3,4,3′,4′‐benzophenonetetracarboxylic dianhydride (BTDA) (1), phthalic anhydride (PA), urea, and metal salts such as CuCl2, CoCl2, and FeCl3etc. at 170°C. In the case of copper, the diPc monomer2or3and the dimer4or5could be synthesized. Those copper complexes are stable to all of the chemical procedures. However, the core metals of Fe(III), Co(II), Ni(II) and Zn(II)‐diPc were partially removed in the acid treatment. Metal phthalocyanine derivatives which have four carboxyl groups in the peripheral site, metal‐[2,9or10(2,16or17)bis(3,4‐dicarboxybenzoyl)] phthalocyanine(daPc) (a = acid)6or7, were synthesized by hydrolysis of the metal‐diPc. The metal‐daPc are soluble in water, in aprotic solvents such asN,N′‐dimethylformamide, and also in sulfuric acid. The physicochemical properties of some metal‐daPc der

ISSN:0025-116X    

DOI:10.1002/macp.1977.021780703

出版商:Hüthig&Wepf Verlag    

年代:1977

数据来源: WILEY

摘要:

AbstractThe syntheses and polycondensations ofNε‐Z‐L‐Lys‐Gly‐L‐Pro (5),L‐Pro‐Nε‐Z‐L‐Lys‐Gly (11), Gly‐L‐Pro‐Nε‐Z‐L‐Lys (17),Nε‐Z‐L‐Lys‐Gly‐L‐Ala (23),Nε‐Z‐L‐Lys‐Gly‐L‐Pro‐L‐Ala‐Gly‐L‐Pro (35), Gly‐L‐Glu(OBut)‐Nε‐Z‐L‐Lys‐Gly‐L‐Pro‐L‐Pro (46), and Gly‐L‐Pro‐Nε‐Z‐L‐Lys‐Gly‐L‐Pro‐L‐Pro (54), are described. The polymers were separated by gelchromatogra

ISSN:0025-116X    

DOI:10.1002/macp.1977.021780704

出版商:Hüthig&Wepf Verlag    

年代:1977

数据来源: WILEY

摘要:

AbstractAcrylonitrile (AN) and butadiene (BD) were copolymerized in the presence of binary C2H5AlCl2MtXn(MtXn= metal halide or metal alkoxide) and ternary ZnCl2RmMtXnVOCl3(RmMtXn= metal alkyl or alkylmetal chloride) catalytic systems. The yield of the copolymer (mole ratio of units AN/BD = 1:1) formed in the presence of the above systems, and the effects of the molar proportion of catalyst components, of the reaction temperature and time on the copolymer yield in some systems were determined. The role of individual components of binary and ternary catalytic systems in the copolymerization is disc

ISSN:0025-116X    

DOI:10.1002/macp.1977.021780705

出版商:Hüthig&Wepf Verlag    

年代:1977

数据来源: WILEY

摘要:

AbstractCopolymerizations of 3‐vinyl‐1,4‐butyrolactone (1) and acrylonitrile (2) initiated by dibenzoyl peroxide or 2,2′‐azoisobutyronitrile were carried out. The following reactivity ratios were found for the bulk copolymerization at 70°C for1:r1= 0,078±0,037 and for2:r2= 4,7±0,3. In addition the valuesQ1= 0,033 ande1= 0,053 were obtained. The ring opening and the ring closing of the lactone moiety in the polymer with an alkaline and an acid were found to b

ISSN:0025-116X    

DOI:10.1002/macp.1977.021780706

出版商:Hüthig&Wepf Verlag    

年代:1977

数据来源: WILEY

摘要:

AbstractThe polymerization mechanism of 1,6‐anhydro‐2,3,4‐tri‐O‐benzyl‐β‐D‐glucopyranose (1) was investigated in order to synthesize 2,3,4‐tri‐O‐benzyl‐[1→6]‐α‐D‐glucopyranan (2a) and [1→6]‐α‐D‐glucopyranan (2b) (dextran) with high molecular weight. It was found that the optimum polymerization time to obtain high molecular weights was 40min when the monomer was polymerized in methylene chloride at −60°C. Stereoregular2awith a\documentclass{article}\pagestyle{empty}\begin{document}$ \overline {DP} _{\rm n} $of 1800 (M̄n= 777000), which was about twice as high as the highest\documentclass{article}\pagestyle{empty}\begin{document}$ \overline {DP} _{\rm n} $previously reported, was obtained in 77% yield by polymerizing the monomer with 0.8 mole‐% PF5as catalyst applying a monomer‐to‐solvent weight/volume ratio of 50%.2awith a high molecular weight was debenzylated to give2bwith a\documentclass{article}\pagestyle{empty}\begin{document}$ \overline {DP} _{\rm n} $of 446 (M̄n= 72300). The α‐stereospecificity and the solid state of the synthetic dextran were investigated by means of optical r

ISSN:0025-116X    

DOI:10.1002/macp.1977.021780707

出版商:Hüthig&Wepf Verlag    

年代:1977

数据来源: WILEY

摘要:

AbstractThe initiation of various vinyl monomers withtert‐butoxyl radicals derived from the decomposition of di‐tert‐butyl peroxalate (DBPOX) was investigated by using the spin trapping technique with 2‐methyl‐2‐nitrosopropane (BNO), to detect and identify the intermediate radical species, and to evaluate the monomer reactivities toward thetert‐butoxyl radical. When the reaction of DBPOX with vinyl monomers, which have no α‐methyl group (CH2CH(X)), was carried out in the presence of BNO at room temperature, the propagating radical1((H3C)3COCH2CHX) was trapped as its nitroxyl radical. However, in the cases of using α‐methylvinyl monomers (CH2CH(X)CH3), such as methyl methacrylate and methacrylonitrile, two kinds of radicals,6((H3C)3COCH2C(X)(CH3), similar to1) and8(CH2CH(X)CH2), were trapped as corresponding nitroxyl radicals. The coupling constants of the nitroxyls obtained from1and6were determined and discussed on the basis of their structure. When these reactions were performed in a reference solvent,p‐xylene, the above radicals,1(or6) and/or8, together with thep‐tolylmethyl radical (2), were trapped as their nitroxyls. From the ESR peak areas the relative reactivities of vinyl monomers toward thetert‐butoxyl radical were evaluated and found to depend not only on the polar nature, but also on the resonance effect of the substituents. In α‐methylvinyl monomers such as methyl methacrylate, the hydrogen‐abstraction from the α‐methyl

ISSN:0025-116X    

DOI:10.1002/macp.1977.021780708

出版商:Hüthig&Wepf Verlag    

年代:1977

数据来源: WILEY

摘要:

AbstractThe mechanism of photo‐decomposition of dibenzoyl disulfide (DBDS) in benzene or in monomers, and the evaluation of relative reactivities of various vinyl monomers toward the benzoylthiyl radical (4) were investigated by means of the spin trapping technique using 2‐methyl‐2‐nitrosopropane (BNO). When DBDS photo‐decomposed in benzene at 22±2°C in the presence of BNO, both4and benzoyl radicals were trapped as their nitroxyl radicals, indicating that both SS and CS bonds in DBDS were decomposed during its photolysis. However, when the photo‐decompositions were performed in the monomers, propagating radicals (7) were trapped, but no allyl‐type radicals (11). The coupling constants of the nitroxyl radicals of various propagating radicals were determined. From the ESR spectra of the systems DBDS/vinyl monomers/methyl methacrylate (as reference)/BNO the relative concentrations of the nitroxyls, [8]/[10, X = COOCH3], were determined by computer simulation, and the relative reactivities of the vinyl monomers toward4were estimated. It was found that the relative reactivities of these monomers are correlated with theirevalues to give a linear relationship with a negative slope, similar to those toward thetert‐butoxyl radical found

ISSN:0025-116X    

DOI:10.1002/macp.1977.021780709

出版商:Hüthig&Wepf Verlag    

年代:1977

数据来源: WILEY

摘要:

AbstractL‐Phenylalanine NCA and glycine NCA react with excess diisopropylamine or dicyclohexylamine to give only polymeric products. In contrast, excess morpholine or diethylamine produces no polymerization but instead yield amino acid amides (2) and hydantoic acids (6), which indicate the intermediate formation of NCA anions4, which are in equilibrium with the isomeric α‐isocyanatocarboxylates (5). Diisopropylamine and dicyclohexylamine in the presence ofN‐acetylglycine NCA (13) yield also quantitative polymerization of glycine NCA, from which oligomers14with acetyl and NCA end groups may be isolated. Under the same conditions morpholine and diethyl amine yield no polymerization, since these amines are acylated by excessN‐acetylglycine NCA. These results show that secondary amines with small substituents react preferentially as nucleophiles so that the NCA‐polymerization proceeds, as with initiation by primary amines, through propagation by nucleophilic end groups. Secondary amines with bulky substituents, in analogy with the tertiary amines, produce only NCA anions which polymerize according to the “activated monomer mechanism”, i.e., through reaction with the electrophilic NCA chain end. Apparently contradictory experiments ofSeeneyandHarwoodwere reinvestigated and the results

ISSN:0025-116X    

DOI:10.1002/macp.1977.021780710

出版商:Hüthig&Wepf Verlag    

年代:1977

数据来源: WILEY