Showing papers in "Polymer Degradation and Stability in 1983"

TL;DR: In this paper, the thermal degradation to 500°C of urea-formaldehyde polycondensate occurs in four successive steps, in which partial volatilisation takes place while the polymer undergoes chemical modification to give progressively more stable structures.

TL;DR: In this paper, the mechanism of production of carboxylic acids during the photo-oxidation of an ethylene-propylene copolymer is discussed, which involves the photolysis of a complex between neighbouring hydroperoxide and ketone groups.

TL;DR: In this article, the nature of the processes which occur in epoxy resins and in model compounds is discussed with reference to changes in the ultraviolet, infra-red and 13C and 1H NMR spectra.

TL;DR: The photo-degradation of bisphenol A polycarbonate films has been studied as a function of the partial pressure of oxygen and relative humidity at the gas/solid interface as discussed by the authors.

TL;DR: In this paper, the evolution of sulphur dioxide and carbon dioxide during the reaction between concentrated sulphuric acid and low density polyethylene, isotactic polypropylene and atactic polypolypropylene at 100-125°C has been followed.

TL;DR: In this article, it was shown that galvinoxyl (G·), a stable aryloxyl radical, is converted to the corresponding phenol(GH) in polypropylene during processing.

TL;DR: In this article, the principal characteristics and products of thermal degradation of an oligomeric phosphorus containing polyol, poly(butylene phenylphosphonate) (I), and the same compound endcapped with phenyl isocyanate, bis(phenyl carbamate) (II) were studied.

TL;DR: In this paper, the role played by photo-oxidation and its sensitivity to ultraviolet irradiation in air of various elastomeric substances has been explained in terms of energy transfer phenomena, and changes in macromolecular chains and network formation have been followed.

TL;DR: In this article, a series of pentaerythritol diphosphites (PEDP) was used to study the effect of structure on the decomposition of 1-methyl-1-phenylethyl hydroperoxide (CHP) in chlorobenzene under nitrogen at 75°C.

TL;DR: The effect of concentration on the light stabilizing efficiency of three metal chelates in polypropylene film has been examined in this article, and the results confirm earlier conclusions that the photo-oxidation products of the first two Chelates are photo-active, whereas those of the latter are themselves photo-stabilisers.

TL;DR: In this article, it was shown that a thiolamide antioxidant, 4-mercaptoacetamido diphenylamine (MADA) can be reacted with both polypropylene and polyethylene in a mechanochemical process.

TL;DR: In this paper, the thermal oxidation behavior of three hindered piperidine compounds has been examined in polypropylene film by oven ageing in air at 140°C together with its subsequent effect on rate of photo-oxidation.

TL;DR: In this paper, the photo-oxidation of two copolymers of butadiene and acrylonitrile (NBR rubbers) was compared under the same experimental conditions.

TL;DR: In this paper, the principal characteristics and products of thermal degradation of a series of polyurethanes incorporating a range of concentrations of phenyl phosphonate structures were examined, and the evidence has been accounted for in terms of acceptable mechanisms.

TL;DR: In this article, a study of the oxidation of amorphous APP and IPP in the condensed phase and in 1,2,4-trichlorobenzene solution was made, and it was found that the oxidation in solution follows the kinetic rules of degenerate radical chain reactions under steady-state conditions.

TL;DR: In this article, the thermal antioxidative behavior of three metal chelates in polypropylene film has been examined using hydroperoxide analysis and infra-red spectroscopy, and the results suggest that metal chelsates compete effectively with oxygen for macroalkyl radicals thermally and photochemically.

TL;DR: A series of sulphonated 2-hydroxybenzophenones containing 4-alkyloxy substituents of varying chain length has been synthesized and applied to wool fabrics as discussed by the authors.

TL;DR: In this article, the effect of calcium and nickel stearates on the photo-stabilizing action and photo-decomposition of one calcium and two nickel metal chelates in polypropylene has been examined using infra-red and ultraviolet derivative spectroscopy.

TL;DR: In this article, the complex interaction between coloured pigments, a primary antioxidant and a hindered piperidine compound in the photo-stabilisation of polypropylene has been examined using infra-red absorption spectros-copy.

TL;DR: In this paper, the mechanisms of reactions which occur on heating mixtures of Bi compounds and a chloroparaffin, which are suitable fire retardant additives for polymers, have been studied.

TL;DR: The photo-stabilising action of a new aliphatic p-hydroxybenzoate light stabiliser, Cyasorb® UV 2908 (American Cyanamid Company), has been examined in polypropylene film, with the aid of a number of related compounds, by both normal and derivative uv absorption, infra-red techniques and hydroperoxide analysis as discussed by the authors.

TL;DR: In this article, the photo-stabilising action of three metal chelates in unprocessed and processed polypropylene is examined using normal and second order derivative ultraviolet and infra-red spectroscopic techniques and hydroperoxide analysis.

TL;DR: Sulphur-containing antioxidants are shown to react with an ethylene-propylene-diene terpolymer in a mechanochemical process as mentioned in this paper, and high yields of adduct are formed in the case of thiols.

TL;DR: In this article, the degradation of PVA was investigated and it was concluded that the observed increase in the rate of deacetylation is due to weakening of the CO bonds attaching acetate groups to the polymer backbone as a result of complex formation between the carbonyl groups and zinc bromide.

TL;DR: In this article, the main characteristics of the evolution of HCl and SbCl3 during the thermal degradation of chloroparaffin-Sb2O3 mixtures, which are typical fire retardant additives for polymers, have been studied.

TL;DR: In this article, the effect of an antioxidant, 2,2′-thiobis(4,6-di-tert-butylphenol) (I) and of the derived sulphoxide (II) and sulphone (III), on the decomposition of tertbutyl hydroperoxide (IV) at 65, 75, 85 and 100°C was investigated.

TL;DR: In this paper, a logical extension to the simple model has been proposed in which several shearing zones of differing severity operate in parallel, and the consequences of this new model for the kinetics of the shear degradation process are explored in detail and tested experimentally.

TL;DR: In this paper, the stabilising activity of hindered phenols was investigated in free radical photo-oxidative and singlet oxygen oxidative degradation of cis-1,4-polybutadiene in solution.