摘要:

Novel pyrrones were synthesized by one-stage polycondensation in polyphosphoric acid of 2,3,5,6-tetraamino-l,4-benzoquinone with pyromellitic anhydride, 3,3′,4,4′-benzophenonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, or 3,4,9,10-perylenetetracarboxylic dianhydride. The prepared polymers showed a considerable percentage of imide linkages, so they were heated at 350°C under high vacuum to increase the ring closure to the pyrrone structure. The polymers were insoluble in all common polar aprotic solvents, even in dimethylacetamide-water mixture, after reduction with sodium dithionite, but were slightly soluble in concentrated sulfuric and methanesulfonic acid. The thermal decomposition of the polymers (weight loss 5%) started above 400°C both under nitrogen and in air.

ISSN:0022-233X    

DOI:10.1080/00222338608063384

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

To investigate their applicabilities as photocurable formulations, photochemical reactions of poly(allylaminophosphazenes) with polythiols of ethylene glycol dimercaptoacetate or trimethylol-propane tri(3-mercaptopropionate) were carried out in the presence of photoinitiators. As a model reaction, hexaallylaminocyclo-triphosphazene(II) was reacted with polythiols, and the thermal properties were investigated. Benzoin alkyl ethers were employed as photoinitiators; in particular, benzoin methyl ether (BME) gave better results in photo reactions. Trimethylolpropane tri(3-mercaptopropionate) was more effective than ethylene glycol dimercaptoacetate in photocrosslinking. The photoreactive system of polyphosphazene containing allyl groups/BME photoinitiator/polythiol was found to be an efficient photocurable system.

ISSN:0022-233X    

DOI:10.1080/00222338608063385

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The copolymerization of glycidyl methacrylate with styrene was carried out in bulk by free-radical initiation. The composition of the copolymers were determined by1H-NMR, IR, and chemical analysis. The monomer reactivity ratios were calculated by the YBR method from the copolymer composition data. The values obtained for different techniques were compared.

ISSN:0022-233X    

DOI:10.1080/00222338608063386

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Poly(N,N-diacylhydrazone)s, which contain imide and imine functions linked by nitrogen-nitrogen bonds, were synthesized from terephthalaldehyde dihydrazone and aromatic and aliphatic dianhydrides. One of the aromatic polymers was also prepared from N,N'-diamino-l,4,5,8-naphthalenetetracarboxylic diimide and terephthaldehyde. The polymers exhibited moderate thermal stability and were shown to degrade initially by cleavage of nitrogen-nitrogen bonds.

ISSN:0022-233X    

DOI:10.1080/00222338608063387

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

A systematic investigation has been conducted of the effect of various phenols (mono- and bicyclic) on the potassium mono-persulfate-initiated polymerization of methyl methacrylate catalyzed by Na2S2O2in aqueous medium at 45°C. It is found that all the phenols, irrespective of their low or high transfer constants, behave as weak retarders within a certain concentration range (0.0005–0.0025 M), above which they behave both as inhibitors and retarders. The rate of this process is dependent upon the substituents in the phenols and often on their positions. For comparison, the reaction has also been studied in the absence of phenols, and the effect of monomer, initiator, and temperature on the rate has been noted. The mechanism of inhibition and retardation has been proposed and various rate parameters have been evaluated.

ISSN:0022-233X    

DOI:10.1080/00222338608063388

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Radical poly(vinyl chlorides), (PVC), obtained in bulk and in suspension polymerizations, and their low molecular weight extracts have been thoroughly studied by high-field NMR to obtain better qualitative and quantitative analyses of their structural defects. Assignments have been achieved by1H-1H decoupling experiments and hyperfine spectral structure analysis of model compounds and low molecular weight extracts. Strong effects of the nature of the solvents used in1H-NMR analysis were observed. Most of the defects of these radical PVC's have been quantitatively estimated in terms of average number values in correlation with their [Mbar]n. End-groups of type [I'] (= −CH2−CH˭CH‒CH2C1) are about 0.5 per chain; internal double bonds can only be estimated by difference, and their amount increases with increasing conversion. A very low quantity of vinyl chain end [I'] (˭ ‒CHC1‒CH˭CH2) has been found only in low molecular weight extracts. For the three probable saturated chloromethyl ends [II] (˭‒CHCl‒CH2Cl), [III] (˭ ‒CH2‒CH2Cl), and [IV] (˭ >CH‒CH2C1), only [II] and [III] were definitely identified. Finally, in taking into account all the endgroups, it has been concluded that branches would be grafted throughout the process. On the average, 4 to 5 branches have been found per chain of high molecular weight PVC.

ISSN:0022-233X    

DOI:10.1080/00222338608063389

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Polyamideimide was synthesized from rosin-maleic anhydride adduct by the reaction of its acid chloride with diaminodiphenyl-methane. The same polymer has also been prepared by the self-polycondensation of the amino acid prepared from the adduct and diaminodiphenylmethane in the presence of thionyl chloride at ambient temperature. The amino acid and the polymer were characterized by IR spectra and elemental analysis. The polymer was found to be soluble only in highly polar solvents. The inherent viscosity of the polymer was found to be low, indicating low molecular weight. The x-ray diffraction data indicated that the polymer was amorphous. The solubility parameter calculated from Small' group contribution agrees well with the experimental value. Ther-mogravimetric analysis, differential thermal analysis, and isothermal aging showed that the polymer was fairly thermostable.

ISSN:0022-233X    

DOI:10.1080/00222338608063390

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Xanthone and 1-hydroxyxanthone polymers were prepared by the Kostanecki reaction on salicylic acid-formaldehyde and 4-(amino, chloro, and bromo)-salicylic acid-formaldehyde polymers, respectively, with phenol and resorcinol. All the xanthone polymer samples were characterized by elemental analysis, by IR spectral study, and by TGA. Xanthone polymers were also screened for their antifungal activity against a variety of fungi.

ISSN:0022-233X    

DOI:10.1080/00222338608063391

出版商:Taylor & Francis Group    

年代:1986

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:10.1080/00222338608063383

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor