摘要:

AbstractAmphipathic lipopeptides CnSarpwith a hydrophobic aliphatic chain, Cn, and a hydrophilic peptidic chain of polysarcosine, Sarp, were synthesized by two methods, a step‐by‐step method and a polymerization method. In the step‐by‐step method, the sarcosine residues are added one by one at the end of a fatty amine (n‐alkylamine,n= 12,14,16,17,18). In the polymerization method, sarcosineN‐carboxyanhydride is polymerized initiated by the amino end of a fatty amine. In concentrated water solution, lipopeptides CnSarpexhibit mesophases whose structure was determined by means of X‐ray diffraction. Three types of mesomorphic structures (lamellar, cylindrical hexagonal, and body‐centred cubic) and two types of polymorphism (one as a function of the length of the peptidic chains, the other as a function of the water content of the mesophases) were established. Furthermore, the respective influence of the factors, governing the type of structure of the mesophases and the values of their geometrical parameters

ISSN:0025-116X    

DOI:10.1002/macp.1986.021870301

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractNew phospholiposaccharides OT‐6‐DPPE and OT‐2‐DPPE were synthesized by linking the α‐amino function of the asparagine residue of the glyco‐amino acid OT from hen ovotransferrin (that contains only Man and ClcNAc residues) to the primary amino group of the polar head of 1,2‐dipalmitoylphosphatidylethanolamine (DPPE) via a suberoyl or a succinoyl bridge. The structural study by X‐ray diffraction showed that the phospholiposaccharide OT‐6‐DPPE exhibits a lamellar structure in concentrated aqueous solution and in the dry state at room temperature; in this lamellar structure, the paraffinic chains are crystallized, hexagonally packed, and tilted as in the Lβ, structure of synthetic phospholipids, while the saccharidic chain adopts an “Y‐shaped conformation”, A comparison with the previously synthesized liposaccharide OT‐16, formed by the same glyco‐amino acid OT but linked to palmitic acid and exhibiting a cubic structure in which the saccharidic chain adopts a slightly deformed “T‐shaped conformation”, shows that it is possible to induce a conformational change of the saccharidic chain of hen ovotransferrin by changing the nature of the “hydrophobic

ISSN:0025-116X    

DOI:10.1002/macp.1986.021870302

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractThe ester groups of copolymer beads, prepared from methyl acrylate and 1,4‐bis(vinyloxy)‐butane, were substituted by aminolysis with hexamethylenediamine or aminoalcohols. The resulting gel carrying amino groups was transferred into an anion exchanger by alkylation with 2‐chloroethanol or into a cation exchanger by reaction with succinic anhydride. Hydrazinolysis of the starting copolymer beads resulted in gels with hydrazide groups which subsequently can be derivatized. Gels with hydroxyl groups linked to the matrix by means of spacers were obtained by reaction of the succinylated gels with 2‐aminoethanol. Phosphorylation of these hydroxyl groups afforded strongly acidic cation exchangers. The yields of the derivatized products are higher and the preparations are easier than those of the known methods. The 11 gel derivatives synthesized from the starting gel are mechanically stable, resistent to hydrolysis in the pH range between 1 and 14, chemically stable at temperatures up to 130°C and obtainable with a variety of pore sizes. The derivatized, cross‐linked polymer beads, applicable in aqueous systems as well as in organic solvents, should find application in chromatography, in solid‐phase synthesis and as basic gels in biotechnic

ISSN:0025-116X    

DOI:10.1002/macp.1986.021870303

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractBenzoylation of metalatedN‐benzoyllactams, derived from 7‐, 9‐ and 13‐membered lactams, gives rise to bothN‐benzoylenol esters (1) andN,2‐dibenzoyllactams (3), whereas in the case of derivatives of 5‐ and 6‐membered lactams only products3byC‐acylation in position 2 were isolated. In the propionylation ofN‐benzoyl‐ orN‐propionyl‐6‐hexanelactam, only products ofO‐acylation were formed. The aminolysis of3gave rise to 2‐benzoyllactams (4). For selected compounds of type1–4the activation effect in the anionic polymerization of 6‐hexanelactam was found to be comparable with that ofN‐acyllactams. The equilibrium aci

ISSN:0025-116X    

DOI:10.1002/macp.1986.021870304

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractLiquid prepolyesters (PPE) were obtained from castor oil and dibasic acids, viz. oxalic, malonic, succinic, glutaric, adipic, suberic and sebacic acids. All these prepolyesters were subsequently copolymerized with acrylamide by radical polymerization initiated with benzoyl peroxide. The resulting prepolyester (PPE)/polyacrylamide (PAm) interpenetrating polymer networks (IPN's) were characterized by elemental analyses, solubility behaviour, IR spectral study, differential scanning calorimetry and thermogravimetry. The transition behaviour was analyses for one IPN by the Ozawa and the Kissinger methods for calculating the various kinetic parameters.

ISSN:0025-116X    

DOI:10.1002/macp.1986.021870305

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractOligo(oxyethylene)s immobilized as pendant groups on a polymethacrylate‐based resin were used as phase transfer catalysts in the reaction of solid alkali phenoxides with octyl halides in toluene and in the synthesis of benzyl acetate from benzyl bromide and solid alkali acetates in chloroform. The resins are cross‐linked homopolymers or copolymers of methyl ethers of oligo(ethylene glycol) methacrylates of the general formula H2CC(CH3)COO(CH2CH2O)nCH3withn= 4 (MG4), 8 (MG8) or 22 (MG22), the comonomers being styrene, methyl methacrylate (MMA), acrylonitrile or 4‐vinylpyridine. The conversion of the organic halides into the respective products were found to be all pseudo first order reactions and the observed rate constants are proportional to the amount of added catalyst and decrease with increasing crosslinking density of the catalyst. Catalysts with longer oligo(oxyethylene) chains have considerably higher activity. Incorporation of more than 50 mol‐% MMA comonomer decreases the catalytic activity at least for the benzyl bromide reaction, but the structure of the comonomer has no significant effect. The catalysts are easily synthesized in large quantities from commercially available

ISSN:0025-116X    

DOI:10.1002/macp.1986.021870306

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractThe transesterification ofS‐phenyl thiobenzoate with 1‐butanol, catalysed with metal salts, was studied as a model reaction for the polyester synthesis. The metal salts were found to interact with both the alcohol and the thioester. Mn(OCOCH3)2· 4H2O, the most active catalyst, shows a higher kinetic order as well as a greater temperature dependence than the less active catalyst LiOCOCH3· 2H2O, whereas the uncatalysed reaction shows the smallest temperature dependence. The application of the catalysts for polyester formation was examined withS,S‐diphenyl 1,4‐benzenedicarbothioate and triethyleneglycol. The molecular weight of the resulting polyester was found to increase with increasing catalytic activity of the metal salt in the corresponding monofunctional model

ISSN:0025-116X    

DOI:10.1002/macp.1986.021870307

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractA series of multifunctional cationic initiators was synthesized from 1,5,9‐cyclododecatriene and from methylbenzenes by the Wohl‐Ziegler reaction withN‐bromosuccinimid. The initiators were treated with silver perchlorate to prepare star‐shaped polytetrahydrofurans with three to s

ISSN:0025-116X    

DOI:10.1002/macp.1986.021870308

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractGlycerol was used as a very suitable compound to prepare reactive derivatives of aldehydes and ketones allowing reaction with polymerizable groups such as methacryloyl chloride. By radical polymerization of methacryloyl derivatives of acetals, synthesized from glycerol and progesterone or its models, polymers were obtained bearing on each constitutional unit a drug covalently linked by two types of bonds which can be cleaved by hydrolysis.

ISSN:0025-116X    

DOI:10.1002/macp.1986.021870309

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractThe thermodynamic compatibility of dilute, solid solutions of poly(propylene glycol) (PPG) (mass‐average molar massM̄w= 3900 g/mol) in poly(methyl methacrylate) (PMMA) (M̄w= 550000 g/mol) was investigated by means of small‐angle X‐ray scattering. The results of the analysis show that PPG is molecularly dispersed in the solid, amorphous matrix of PMMA, and that the molecules display the typical statistical coil macroconformation of polymers in dilute, liquid solution, whereby the numerical value of the second virial coefficient seems to point to the unperturbed nature of the coils. This behaviour, consistent with the concept of “interpenetration of segments”, is in total agreement with the experimentally measured compositional variation of the glass transition temperature of

ISSN:0025-116X    

DOI:10.1002/macp.1986.021870310

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY