摘要:

Novel methods of synthesis of spiro acyloxyphosphoranes are described emphasizing the significance of the first isolated instance of these new species. Then, the no-catalyst alternating copolymerizations of the combinations of cyclic phosphorus(III) compounds (serving as nucleophilic monomer, MN) with acrylic acid derivatives and with α-keto acids (electrophilic monomer, ME) are mentioned. These copolymerizations proceed without added initiator. Spiro oxyphosphoranes play an important role in the copolymerization scheme in the equilibrium with the+MN- ME−zwitterion, the key intermediate of the copolymerization. Finally, new reactions of spiro acyloxyphosphoranes with nucleophiles, alcoholysis and aminolysis polymerizations are presented.

ISSN:0022-233X    

DOI:10.1080/00222337908068104

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The following aspects of polymer reactivity are discussed: (a) effects due to differences in the microenvironment of the polymer domain and the solvent; (b) effects due to spatial requirements of enzymatic attack on polymer side chains; (c) heterogeneous reactions of gel-bound functional groups with a reagent in a solution phase; and (d) the relation of the conformational mobility of a polymer and its low molecular weight analog.

ISSN:0022-233X    

DOI:10.1080/00222337908068105

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The acceleration effect of poly(ethylene oxide) on nucleophilic reactions was investigated. The enhancement of the reaction rate was interpreted by the cooperative solvation of alkali metal ions with ethereal oxygens of PEO resulting in active nucleophilic anions. In relation to the complex formation of alkali metal ions with PEO, the oligo(ethylene oxide) derivatives were prepared as the synthetic ionophores, which were able to transport alkali metal ions selectively through a liquid membrane against the alkali metal ion concentration.

ISSN:0022-233X    

DOI:10.1080/00222337908068106

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

A large number of naturally occurring polyanionic materials are known each of which possesses its own set of physiological properties. Within recent years, a wide variety of synthetic polyanions have become available, and investigators have compared their physiological properties with the naturally occurring polyanions. Perhaps, the most widely investigated synthetic polyanion is the 1:2 regularly alternating cycloco-polymer (DVE-MA) of divinyl ether (DVE) and maleic anhydride (MA), first discovered in these laboratories in 1951. This material has been investigated extensively, both from the standpoint of its chemical structure and its biological activity. Although certain aspects of its structure remain to be determined, it has been shown to possess a wide spectrum of biological activity. It possesses antitumor as well as other activities and is an interferon inducer. Many structural modifications of DVE-MA have been synthesized which also possess antitumor activity and interferon-inducing capability. A recent structural modification incorporated 5-fluorouracil (5-FU) into DVE-MA. This polymer is hydrolyzed readily to release 5-FU, and the material exhibited considerable activity against P388 lymphocytic leukemia. A novel series of polyanions have been synthesized via reactions of N-substituted triazolinediones with a variety of olefins and diene polymers. The synthesis and physiological properties of certain of these polyanions are discussed in this paper.

ISSN:0022-233X    

DOI:10.1080/00222337908068107

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The uncatalyzed reactions of N-vinylcarbazole with electrophilic olefins have been studied. The products included both small molecules and polymers. N-Vinylcarbazole reacted with tricarbomethoxyethylene in inert solvents such as benzene at 110°C to form trimethyl 1-carbazol-9-ylbut-1-ene-3,4,4-tricarboxylate. Donor solvents such as acetone or acetonitrile gave trimethyl-1-carbazol-9-ylcyclobutane-2,2,3-tricarboxylate. A variety of additives in the inert solvents also diverted the product from the 3,4,4-tricarboxylate to the 2,2,3-tricarboxylate. These included oxygen, several silver salts, metallic mercury, diphenylpicrylhydrazyl, and tributyltinhydride. Polymers also formed in low yields in many of these reactions. Either homo-polyvinylcarbazole or the alternating copolymer of N-vinylcarbazole with tricarbomethoxyethylene formed, depending on the solvent. Pyridine prevented the formation of the former, and tert-butylhydroquinone the latter; thus their formation is ascribed to cationic and free radical processes, respectively. N-Vinyl-carbazole reacted with tetracarbomethoxyethylene at 155°C in either inert or donor solvents to produce tetramethyl 1-carbazol-9-ylbut-1-ene-3,3,4,4-tetracarboxylate. In the presence of DPPH, tetramethyl 1-carbazol-9-ylcyclobutane-2,2,3,3-tetracarboxylate was the product. N-Vinylcarbazole reacted with dimethyl cyanofumarate at 28°C in inert solvents with air present to give dimethyl 4-cyano- l-carbazol-9-ylbut-l-ene-3,4-dicarboxylate, while donor solvents with air present gave dimethyl 2-cyano-1-carbazol-9-ylcyclobutane-2,3-dicarboxylate. N-Vinylcarbazole reacted with 1,2-disubstituted ethylenes at 155°C to give only copolymers. The above results are interpreted as proceeding by electron transfer from N-vinylcarbazole to the electrophilic olefin. In inert solvents the N-vinylcarbazole cation-radical transfers a proton to the anionradical and couples to form the 1-butene derivative. In donor solvents or in presence of additives which scavenge or stabilize the anion-radical, the N-vinylcarbazole cation-radical reacts instead with the electrophilic ethylene monomer. The resulting butane radical-cation cyclizes and leads to the cyclobutane derivatives. This new cyclobutane synthesis extends the cyclodimerization mechanism of Tada, Shirota, and Mikawa and of Ledwith for electron-rich olefins to the cycloaddition of electron-rich olefins to electron-poor olefins.

ISSN:0022-233X    

DOI:10.1080/00222337908068108

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Surface properties of styrene-tetrahydrofuran (St-THF) block copolymers (AB and ABA type) were studied. Morphology observed by electron micrography showed the formation of fibrils of poly-THF covered with poly-St for THF-rich block copolymers and the accumulation of poly-THF segments for St-rich block copolymers. The poly-THF segment was found to have a surface of activity 3 dyne/cm lower than the poly-St segment. Modification of the poly-St surface by adding St-THF block copolymers was examined by measuring the surface tension drop during heating. Inverse gas chromatography of the block copolymers revealed that the surface of St-rich block copolymer changes from poly-St to poly-THF on baking. The contact angle of water droplets was a linear function of surface composition, and water wettability of St-rich block copolymers by accumulation of surface active poly-THF segment was indicated.

ISSN:0022-233X    

DOI:10.1080/00222337908068109

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Synthetic polymers with functional groups, especially where the functional group is a biologically active group, are receiving considerable attention, since such polymeric drugs represent novel drug delivery systems. In this paper methods for the preparation of typical classes of polymers with biologically active groups were explored. As an example of a condensation polymer, primaquine was incorporated in a polymer chain by an allophanate linkage. Primaquine was also substituted on a polyoxyethylene polymer chain as was the N, N-dimethylamino-benzoate group. Oligo(oxyethylene) glycols were endcapped with salicylate or N, N'-dimethylaminobenzoate groups. These functional groups are reversibly linked to polymers and can be removed, for example, by hydrolysis, providing slow and sustained release of the drug. As nondegradable polymers with functional groups, polymers and copolymers of 4-vinylsalicylic acid and 5-vinylsalicylic acid derivatives have been prepared. It was shown clearly that high polymers are active in antibacterial tests, against gram-positive and/or gram-negative bacteria. The activity of poly(4-vinylsalicylic acid) and poly(5-vinyl-salicylic acid) was found to be independent of molecular weight. Selective activity has been obtained by preparing copolymers of 4-vinylsalicylic acid or 5-vinylsalicylic acid with methacrylic acid, a coraonomer whose homopolymer was inactive.

ISSN:0022-233X    

DOI:10.1080/00222337908068110

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0022-233X    

DOI:10.1080/00222337908068103

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor