摘要:

AbstractChloromethyloxirane (CMO) undergoes an asymmetric selective oligomerization with a binary catalyst system comprised of triethylaluminium and an optically active cobalt complex,N,N'‐disalicylidene‐(1R)‐1,2‐cyclohexanediyldiaminatocobalt(II). A series of optically active oligomers obtained were isolated and characterized. Two kinds of linear oligomers were produced with respect to the end groups, namely epoxy‐ and halohydrin‐ended oligomers. A mechanism for the selective formation of linear oligomers by the present catalyst system

ISSN:0025-116X    

DOI:10.1002/macp.1983.021840501

出版商:Hüthig&Wepf Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractPoly(propylene carbonate) (PPC) was treated with diethylzinc in 1,4‐dioxane solution at 30°C, Zn(C2H5)2being used in excess or defficiency with regard to carbonate units. PPC was found to undergo degradation and depolymerization reactions, which were followed via the polymer intrinsic viscosity and the propylene carbonate yield. A model reaction between diethyl carbonate and diethylzinc was carried out too. From the results, a mechanistic view for both pathways, degradation and depolymerization, is propos

ISSN:0025-116X    

DOI:10.1002/macp.1983.021840502

出版商:Hüthig&Wepf Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractThe copolymerization of vinyl chloride (VC) and methyl acrylate (MA) in the presence of ethylaluminium compounds (C2H5AlCl2, (C2H5)2AlCl, and (C2H5)3Al) at low ethylaluminium compound (EAC)/MA mole ratios was investigated. An alternating copolymer was produced in this reaction when an excess of VC in the initial monomer feed was used. The addition of dibenzoyl peroxide (BPO) to the systems containing EAC resulted in an increase of the alternating copolymer yield. In polymerization systems containing EAC resulted in an increase of the alternating copolymer yield. In polymerization systems containing EAC combined with VOCl3an enhancement of the alternating copolymer yield and formation of VC‐rich copolymers were observed. In the polymerization system with (C2H5)3AlVOCl3a VC‐rich copolymer was the main product. It was concluded that VC‐rich copolymers are formed in the random radical copolymerization which occurs when most of EAC is complexed by the alternating copolymer chain. The structure of alternating and VC‐rich copolymers was studied in detail by means of13C NMR spe

ISSN:0025-116X    

DOI:10.1002/macp.1983.021840503

出版商:Hüthig&Wepf Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractIn the polymerization of water‐soluble vinyl monomers, such as acrylamide, sodiump‐sty‐renesulfonate, acrylic acid, and methacrylic acid, using water‐insoluble free radical initiators such as azo or peroxide compounds in the two‐phase system consisting of water and an organic solvent (chloroform/ligroin, volume ratio 1:4), the addition of a small amount of a methylated β‐cyclodextrin, heptakis(2,6‐O‐dimethyl)‐β‐cyclodextrin (DM‐β‐CD) or heptakis(2,3,6‐O‐trimethyl)‐β‐cyclodextrin (TM‐β‐CD), was found to cause a marked increase in conversion of the polymerization. Based on this finding, it may be suggested that the methylated β‐cyclodextrins act as initiator‐carriers which transport the water‐insoluble initiators from the organic phase to the aqueous phase to initiate the

ISSN:0025-116X    

DOI:10.1002/macp.1983.021840504

出版商:Hüthig&Wepf Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractReductive cleavage of derivatives from tetrafluoroethylene photooxidation resulted in perfluorinated polyethers with α,ω‐carboxylic ester groupsB. Their condensation with suitable aliphatic and aromatic diamines gave a new class of elastomers, crosslinkable by organic peroxides. A good balance of low temperature elasticity, resistance to solvents, and thermostability was particularly found for aromatic polyami

ISSN:0025-116X    

DOI:10.1002/macp.1983.021840505

出版商:Hüthig&Wepf Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractTwo new lactam monomers containing vinyl groups were synthesized, namely 1‐benzyl‐3‐methylene‐5‐methyl‐2‐pyrrolidone (1) and 5‐oxo‐2‐pyrrolidinylmethyl methacrylate (2). Their homopolymerization and copolymerizations with methyl methacrylate (MMA), styrene, or methylacrylate were studied. The copolymerization parametersr1andr2were also evaluated. Poly(1) is a stable polymer which decomposes at ≈ 300°C under nitrogen and at 250°C in air. Its pyrrolidone ring is resistant

ISSN:0025-116X    

DOI:10.1002/macp.1983.021840506

出版商:Hüthig&Wepf Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractAcrylic acid (AA) was polymerized with NO2in tetrahydrofuran (THF) and in 1,4‐dioxane. The effects of monomer and initiator concentration and of temperature on polymer conversion, initial rate of polymerization, and molecular weight were studied. The overall activation energy of polymerization was found to be 16,3 kcal mol−1(68,23 kJ · mol−1) and 15,54 kcal · mol−1(65,05 kJ · mol−1) in THF and in 1,4‐dioxane, respectively. High molecular weight polymers (Mca. 105) were obtained. The polymerization appears to be initiated by

ISSN:0025-116X    

DOI:10.1002/macp.1983.021840507

出版商:Hüthig&Wepf Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractAnionic polymerization ofp‐triphenylgermylstyrene (1a) andp‐tributylgermylstyrene (1b) were investigated under high vacuum conditions (≈10−6mbar). Both1aand1bwere readily polymerized with sodium naphthalide, potassium naphthalide, or α‐methylstyrylsodium oligomers to form“living polymers”. The addition of α‐methylstyrene to these living systems gave the triblock copolymer, poly(α‐methylstyrene‐b‐p‐triphenylgermylstyrene‐b‐α‐methylstyrene). Both monomers were also polymerized radically with AIBN as initiator. Some physical properties of the

ISSN:0025-116X    

DOI:10.1002/macp.1983.021840508

出版商:Hüthig&Wepf Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractPolyurethanes6and7based on poly(oxyethylene) (5) were synthesized and investigated for the application as macromolecular chelating agents. 4,4′‐Diaminobenzil (3c) and 4,4′‐diaminobenzil monoxime (4a) were prepared as monomer precursors in 70 and 80% yield. Copolymers were obtained in yields between 40 and 60% by polyaddition of the corresponding diisocyanates3dand4bto poly(oxyethylene) (5) of different chain length and characterized by IR and13C NMR spectroscopy. The application of the resulting polyurethanes containing functional aromatic block units as polychelatogenes was studied in homogeneous phase by membrane filtration. The metal content was determined in both the filtrate and the retentate and in the case of Ni2+at different pH values. At pH 2, for example, the molar binding capacity of a polyurethane sample of6was 3 times as high as t

ISSN:0025-116X    

DOI:10.1002/macp.1983.021840509

出版商:Hüthig&Wepf Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractPhotocrosslinkable block cotelomers were synthesized in three steps. In the first step a monomer M1was telomerized with carbon tetrachloride or chloroform, in the second step a monomer M2with the resulting macrotelogen, and in the third step the hydroxyl groups were esterified by cinnamic acid or acrylic acid. These reactions were carried out with ethyl acrylate (M1)/CCl4by redox catalysis and subsequently with vinyl acetate (M2) by free radical initiation, or with vinyl acetate (M1)/CHCl3by free radical initiation and subsequently with isoprene (M2) by redox catalysis, or with 2‐hydroxyethyl acrylate (M1)/CCl4by redox catalysis, and subsequently with isoprene (M2) by redox catalysi

ISSN:0025-116X    

DOI:10.1002/macp.1983.021840510

出版商:Hüthig&Wepf Verlag    

年代:1983

数据来源: WILEY