摘要:

AbstractThe fundamental basis of the burning of polymers is reviewed and the planning of the present investigations is justified. Preliminary results are given on the effect of chlorinated additives on the pyrolytic decomposition of polyesters.

ISSN:0007-1641    

DOI:10.1002/pi.4980010401

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractSetchkin ignition tests and candle‐burning tests have been shown to provide a numerical index of the effect of flame retardant agent on polyesters. Experimental details for a number of commercial halogenated retardants, which were tested, are given and some conclusions are made about the nature of their actio

ISSN:0007-1641    

DOI:10.1002/pi.4980010402

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractThe intrinsic viscosity of a copolymer has been calculated using the method developed by Fixman. The result shows that the relation [η] =KM1/2may be observed under certain conditions (where [η] is intrinsic viscosity,Mis molecular weight, andKis a constant). However, even in such a case, the ‘unperturbed dimensions’ of the copolymer cannot be obtained in the manner usually adopted for homopolymers. In general, there is no θ state for a copolymer, i.e. no stage at which all interactions between pairs of segments vanish simultan

ISSN:0007-1641    

DOI:10.1002/pi.4980010403

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractA scheme is outlined for the characterisation of a crystallisable polymer using simple basic techniques. In it, the thermal characteristics such as melting point and stability up to the melting point are examined using a microscope. A range of solvents is selected and simple fractionation procedures are investigated. The solution properties of the fractions are studied by viscometry and light‐scattering. Finally the melting points and glass transitions of the fractions are investigated, mechanical and dielectric loss measurements are made and gravimetric analyses of thermal stability are carried out.An example of the application of this scheme to a relatively new polymer, polytrifluoroethoxy phosphazene, is discussed and difficulties encountered as the characterisation scheme progressed are outline

ISSN:0007-1641    

DOI:10.1002/pi.4980010404

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractIonic conduction in continuous polymer films is of two types. Inverse conduction occurs when the resistance of the film runs counter to, and direct conduction when the resistance follows, that of the external solution. The two types are interconvertible; the controlling factor is the water content of the film, which is governed by the nature of the polymer, the mode of preparation of the film, and the conditions of exposure.

ISSN:0007-1641    

DOI:10.1002/pi.4980010405

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractA torsion pendulum has been found to be a sensitive tool to detect the first steps of pyrolysis. It has been shown that some primary bonds break at elevated temperatures, but in the presence of oxygen, new crosslinks can form simultaneously. In resin heated in air, embrittlement due to these crosslinks starts on the surface of the resin and progresses inwards with time.

ISSN:0007-1641    

DOI:10.1002/pi.4980010406

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractThe infra‐red spectra of copolymers of vinyl acetate with acrylic esters and fumaric and maleic di‐esters show no features which enable differentiation one from another. High‐resolution nuclear magnetic resonance, however, shows differences in backbone structure between vinyl acetate‐acrylic esters and vinyl acetatefumaric or maleic esters. Furthermore, there are finer differences between the fumaric and maleic ester copolymers and, with the aid of specially prepared model compounds, it has been established that these differences are accounted for by a greater tendency for the occurrence of fumaric ester sequences than maleic ester sequences in the copolymers. The differing sequence distribution of vinyl acetate‐fumaric ester and vinyl acetate‐maleic ester has been shown to be in qualitative agreement with that expected from reacti

ISSN:0007-1641    

DOI:10.1002/pi.4980010407

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractThe solubility parameter (δ2) of polystyrene was measured by the maximum [δ] method in four series of solvents which were structurally different. In each case δ2varied with the solvent series used, from 8·75 to 9·25 (cal/ml)1/2The enthalpy parameter (XH), which was calculated for polystyrene dissolved in at least one member of each series, was then used to derive δ2, and little or no variation in δ2, with solvent was observed. The average value was δ2= 9·16 ± 0·1 (cal/ml)1/2It has been shown that determination of δ2, from [η]maxcan be solvent‐dependent because of the influence of the entropy termXs. It was concluded that if reliable values of δ2are to be obtained, they should be e

ISSN:0007-1641    

DOI:10.1002/pi.4980010408

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY

ISSN:0007-1641    

DOI:10.1002/pi.4980010411

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY

ISSN:0007-1641    

DOI:10.1002/pi.4980010412

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY