摘要:

AbstractThe radical copolymerization of 9‐anthrylmethyl methacrylate (1) withN‐phenylmaleimide (2), initiated by 2,2′‐azoisobutyronitrile at 60°C in 1,4‐dioxane, was investigated. Simultaneously with the copolymerization a Diels‐Alder cycloaddition of2to the anthracene nucleus takes place as side reaction. A charge transfer complex formation between the two monomers was evidenced by1H NMR spectroscopy. The stability constant of the complex, which is an intermediate in the cycloaddition reaction, was found to be 0,

ISSN:0025-116X    

DOI:10.1002/macp.1985.021860601

出版商:Hüthig&Wepf Verlag    

年代:1985

数据来源: WILEY

摘要:

AbstractThe copolymerization of propylene with 1‐butene was carried out in presence of the catalytic system TiCl4/Mg[(CH2)5CH3]2in heptane. A transparent copolymer with a random distribution (r1·r2= 1,0) was obtained. The catalyst shows a considerably high activity. The rate of monomer addition was found to be independent of the chemical structure of the growing polymer chain end, which is quite different for the copolymerization of ethylene with propyle

ISSN:0025-116X    

DOI:10.1002/macp.1985.021860602

出版商:Hüthig&Wepf Verlag    

年代:1985

数据来源: WILEY

摘要:

AbstractTwo aspects of the reversed‐phase liquid chromatographic separation of α‐hydro‐ω‐butyloligostyrene stereoisomers are presented. In the first part, two‐dimensional NMR is employed to make stereochemical assignments on isolated dimer, trimer and tetramer species. This work established the elution pattern of the stereoisomers as isotactic, heterotactic and syndiotactic for tetramers. In the second part, the elution behavior of these stereoisomers in reversed‐phase chromatography is compared to that observed in size exclusion chromatography, and these comparisons suggest that differences in the effective sizes of the stereoisomers are important factors in the

ISSN:0025-116X    

DOI:10.1002/macp.1985.021860603

出版商:Hüthig&Wepf Verlag    

年代:1985

数据来源: WILEY

摘要:

Abstract2‐, 3‐ and 4‐Acryloylaminobenzoic acids were prepared in overall yields of 72, 78 and 83%, respectively. Radical polymerizations of all three monomers were studied using 2,2′‐azoisobutyronitrile as initiator in 1,4‐dioxane at three different temperatures. The unfractionated polymers were characterized by their physical properties, IR and NMR spectral studies, viscosity measurements and vapour pressure osmometry. The thermal properties were elucidated by therm

ISSN:0025-116X    

DOI:10.1002/macp.1985.021860604

出版商:Hüthig&Wepf Verlag    

年代:1985

数据来源: WILEY

摘要:

AbstractAnionic polymerization of 4‐(tert‐butyldimethylsilyloxy)styrene (2) was investigated under high vacuum conditions (≈ 10−6mbar).2was readily polymerized by lithium naphthalide to form a “living polymer” at −78°C. By subsequent acid hydrolysis of the resulting polymer, a linear, nearly monodisperse polymer of 4‐vinylphenol of known molecular weight was obtained. Block copolymers of2with α‐methylstyrene were also prepared by means of

ISSN:0025-116X    

DOI:10.1002/macp.1985.021860605

出版商:Hüthig&Wepf Verlag    

年代:1985

数据来源: WILEY

摘要:

AbstractAnalytical and kinetic aspects of the photooxidation in the solid state of two polyether‐block‐polyamides1aand1bare described. The block copolymers studied contain different fractions of polyether segments. Nevertheless, their photooxidation presents the same features and concerns mainly the ether groups. In both thermoplastic elastomers,1aand1bvery high stationary concentrations of hydroperoxy groups CH(OOH)OCH2 are observed (0,3 to 0,7 mol · kg−1). These hydroperoxides are, however, photounstable and thermounstable above 60°C. They are converted into hemiacetals OCH(OH)OCH2, saturated esters and formates. The hemiacetal groups are thermounstable, too, and decompose into alcohol and aldehyde groups, the latter being photoxidized in the matrix. The oxygen consumption rate, the primary hydroperoxidation rate, and the rate of accumulation of final products were determined. A mechanism including the photolysis and the thermolysis of the hydroperoxides can account for the formation of the final photoproducts (hemiacetals, es

ISSN:0025-116X    

DOI:10.1002/macp.1985.021860606

出版商:Hüthig&Wepf Verlag    

年代:1985

数据来源: WILEY

摘要:

AbstractStudies of a number of organotin(IV) oxides and sulfides as modifiers of Ziegler‐type propene polymerization catalysts are reported. The general trend observed is that organotin(IV) sulfides provide better catalyst activity‐stereospecificity combinations than the corresponding oxides. Among the various modifiers studied, μ‐thiobis[tri‐butyltin(IV)] was found to exhibit the best overall modifying effect. Combination of an organotin(IV) sulfide with a second modifier of the aromatic amine,N‐oxide, phosphite ester or cyclic ether type in a binary modifier package was shown to lead to catalyst systems with excellent stereospecificities and activities ranging from acceptable to outstanding. Possible interactions and reactions of the organotin modifiers with the components of the catalyst system are

ISSN:0025-116X    

DOI:10.1002/macp.1985.021860607

出版商:Hüthig&Wepf Verlag    

年代:1985

数据来源: WILEY

摘要:

AbstractThe structures of the adducts of 2‐butanone oxime (1) to different diisocyanates were determined by1H NMR spectroscopy. The reaction of diisocyanate blocking is quantitative. The different adducts of1to 4,4′‐methylenediphenyl isocyanate (2), 2‐methyl‐1,4‐phenylene and 2‐methyl‐1,3‐phenylene diisocyanates (8and10) and to the isocyanate resulting from α‐hydro‐ω‐hydroxypoly(oxytetramethylene) and an excess of2, dissociate upon heating to reform the starting materials. The residual water in the NMR solvent reacts partially with the regenerated diisocyanates to give prim

ISSN:0025-116X    

DOI:10.1002/macp.1985.021860608

出版商:Hüthig&Wepf Verlag    

年代:1985

数据来源: WILEY

摘要:

AbstractPolysiloxane‐poly(methyl methacrylate) and polysiloxane‐polystyrene graft copolymers of well‐defined structure and composition were synthesized by hydrosilylation. Polysiloxanes with SiH bonds were prepared by equilibrium ring‐opening polymerization of cyclic siloxane oligomers catalyzed by trifluoroacetic acid. Molecular weight and SiH group content were controlled by the feed ratio. Allyl‐terminated poly(methyl methacrylate) and polystyrene were prepared by the reaction of carboxyl‐terminated prepolymers with allyl glycidyl ether. The hydrosilylation reactions of SiH containing polysiloxanes with these allyl‐terminated polymers produced tailor‐made graft copolymers, which were characterized by their

ISSN:0025-116X    

DOI:10.1002/macp.1985.021860609

出版商:Hüthig&Wepf Verlag    

年代:1985

数据来源: WILEY

摘要:

AbstractDifferent mixtures of (2R,3S)‐ and (2S,3S)‐1,2‐epithio‐3‐methylpentanes (1) were polymerized using anionic (sodium), stereoselective (ZnEt2/H2O, cadmium tartrate) and stereoelective (ZnEt2/R(−)‐3,3‐dimethyl‐1,2‐butanediol (R(−)DMBD)) initiator systems. In all cases a preferential consumption of the (2R,3S)‐diastereoisomer was observed. The reactivity ratios of the two diastereoisomers (2R,3S) and (2S,3S) in the copolymerization, initiated with sodium, were determined:r1= 1,40 ± 0,08 andr2= 0,54 ± 0,05. A low but significant diastereoisomeric enrichment was observed in stereoselective polymerization. It results from different consumption rates for the two diastereoisomers on enantiomorphic sites of the initiator. The election obtained with a stereoelective system is much higher. It is, however, not very different from that observed with isopropylthiiranne, which does not bear an additional chiral center

ISSN:0025-116X    

DOI:10.1002/macp.1985.021860610

出版商:Hüthig&Wepf Verlag    

年代:1985

数据来源: WILEY