摘要:

AbstractThe chemical structures of the aromatic (A) and the aliphatic ester (B) residues of poly(ethylene terephthalate), PET, are evaluated from a comparison of their Hansen solubility parameters, as determined experimentally, and with those calculated for the various residues of PET. From such a comparison it is proposed that the structures of residues A and B are best represented by “hybrid” structures which may be taken as linear combinations of two or more structures rather than by single chemical structures. That is, the 1,4‐carbonyl group which separates the benzene ring of the aromatic residue and the ethylene group of the aliphatic ester residue effectively acts as a common plane between the two residues and is “shared” by the benzene ring and the ethylene glycol group. It is proposed that the extent to which the 1,4‐carbonyl group is “shared” by residues A and B is 0.33 and 0.67, respectively, which is consistent with the most probable molecular conformation of the 1,4‐benzenoid residue of PET as calculated from the data of Tonelli23and Daunbeny et al.21and which gives support to the view that the bond connecting the benzene ring and the carbonyl group is not rigid, but free to rotate as proposed earlier by Flory

ISSN:0021-8995    

DOI:10.1002/app.1977.070210121

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1977

数据来源: WILEY

摘要:

AbstractThe extent of solvent‐induced shrinkage, swelling, and crystallization of polyester is found to be dependent on the initial morphology of the material. However, the nature of the interaction of the nonaqueous solvents with the aromatic and the aliphatic ester residues of poly(ethylene terephthalate) is found to be independent of morphology and only dependent on the differences in the stereochemical nature of the given solvent and polyester residu

ISSN:0021-8995    

DOI:10.1002/app.1977.070210122

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1977

数据来源: WILEY

摘要:

AbstractElectrokinetic properties, namely, zeta potential (ζ), surface charge density (σ), and surface conductivity (Ks) of polyformaldehyde fibers [poly(oxymethylene) fibers] have been studied in the presence of direct dyes, with or without surfactants and an electrolyte. The anionic dyes increased the negative zeta potential of fibers. The increase in ζ was found to be a function of concentration and basicity of the dye in the streaming solution. Thus, the tetrabasic dye gave higher value of negative ζ than the equivalent concentration of the dibasic dye. The cationic surfactant brought about a decrease in negative ζ, giving a point of inflection, while the anionic surfactant increased it. The nonionic surfactant brought about a certain reduction in negative ζ, but failed to give a point of inflection. In the presence of a direct dye, the cationic surfactant brought about considerable reduction in negative ζ, to give a point of inflection. The presence of an electrolyte in the streaming dye solution progressively lowered the negative ζ. In general, σ increased with the increase in the concentration of either a dye or an electrolyte in the presence of a given concentration of the dye in the streaming solution. Results onKsindicated that the surface conductivity of the fibers is a function of concentration of dye, surfactant, and electrolyte. It was, however, observed to be independent of the nature of the surfactant. Although both the dibasic and tetrabasic direct dyes brought about an increase inKs, the extent of increase was dependent upon the basicity of the m

ISSN:0021-8995    

DOI:10.1002/app.1977.070210123

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1977

数据来源: WILEY

ISSN:0021-8995    

DOI:10.1002/app.1977.070210124

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1977

数据来源: WILEY

ISSN:0021-8995    

DOI:10.1002/app.1977.070210125

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1977

数据来源: WILEY