Dynamic thermogravimetric. Analysis in polymer degradation

The processes of thermal and thermal-oxidative degradation taking place in polyethylene (PE) films modified by graft polyacrylic acid (PAA) have been studied by TG and DTA. The mutual influence of the components on the degradation of the macromolecules present in the graft copolymer has been revealed. The increase in thermal stability of PE in the graft copolymers is explained by the decrease in the molecular mobility in PE amorphous regions containing microphase particles of graft PAA.

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Thermal properties of films of polyethylene with graft polyacrylic acid

Polikarpov¹,

Krul

Osipenko³

et al. 1988

“…On the other hand, it seems that the most recent period has given no new stimulus for the study of degradation kinetics, although this was not long ago one of the most used applications of TG [9] and although non-isothermal kinetics has in general attained significant sucesses. On the other hand, it seems that the most recent period has given no new stimulus for the study of degradation kinetics, although this was not long ago one of the most used applications of TG [9] and although non-isothermal kinetics has in general attained significant sucesses.…”

Section: Prospects Of Application Of Ta Methods On Polymersmentioning

confidence: 99%

Prospects of thermal analysis in polymer research

Gömöry

1977

A survey and an analysis of the publications concerned in thermal analysis (TA) published in four renowned journals during the years 1965--1974 were performed. The published data were evaluated from three points of view: TA methods used for polymers, properties and phenomena studied by TA methods, types of polymers investigated by TA methods. From the statistical data were derived the future trends for the application of particular TA methods in polymer science.The methods of thermal analysis have gradually found very wide application in research into the structures and properties of polymers. The first sporadic contributions on the differential thermal analysis (DTA) of polymers date from about 1945, on their isothermal thermogravimetry from about 1949, and on their dynamic thermogravimetry from about 1959. Differential scanning calorimetry (DSC) and quantitative DTA were applied to polymers immediately after their discovery [1 ]. There has been an extraordinary increase in the applications of the three main TA techniques (DTA, DSC, TG) in the physics and chemistry of macromolecules in the past ten years. This is due to several specific circumstances:The design of precise and sensitive automatic equipment eliminated the disadvantages of polymers as objects for TA (low thermal conductivity, low phase transition heats, thermal gradients in measuring cell). TA apparatuses suitable for polymer research are offered at present by several tens of producers and these apparatuses have become virtually standard equipment in laboratories studying the properties of polymers from different aspects.The enormous interest in high-temperature-resistant polymers evoked the need for their evaluation and stimulated the design of new types of thermoanalytical equipment, especially thermobalances. This simultaneity of the needs for methods of evaluating the properties of new polymers and for the development of thermoanalytical equipment was the deciding moment for the spreading of TA methods in the polymer field.In order to assess the present state of the application of TA methods in polymer research, we considered it appropriate to analyse in some detail the range of publications concerning the TA of polymers in the past ten years, i.e. the time of mass adoption of TA methods in polymer research. This analysis of published material forms the substance of the present work. In our opinion, such an analysis not only 10 3-. Thermal Anal 11, 1977

“…Das wohl wichtigste Anwendungsgebiet ist die Untersuchung der relativen Thermostabilit~t und der Abbaumechanismen der verschiedensten Polyrneren, da man mit nut einer einzigen Messung sehr raseh einen Uberblick fiber die thermische Charakteristik einer Probe erhalten kann [2,3]. Von relativer Thermo- stabilit~it des Polymeren muB man im Zusammenhang mit den "dynarnischen" TG-Kurven deshalb sprechen, weil a) eine Reihe von experimentellen Faktoren den qualitativen und quantitativen Verlauf einer TG-Kurve mitbestimmen und b) jede Temperaturstufe beim Aufheizen relativ schnell durchlaufen wird und somit iJber das thermische Langzeitverhalten bei dieser Verfahrensweise nur begrenzte Aussagen m6glich sind.…”

Section: Thermogravimetrie Organischer Faserbildender Hochpolymererunclassified

Die Anwendung Thermoanalytischer Methoden zur Charakterisierung Faserbildender Organischer Hochpolymerer

Zimmermann

Baudisch

1969

A review on the application of thermogravimetry (TG) in the field of fiber-forming organic high polymers is given by examples from the literature and from the work of the author. The investigation of the relative thermostability, their changes by modification of the polymers or by addition of stabilizers and the calculation of kinetic values are particularly stressed. The advantage of derivative thermogravimetry and the necessity for isothermal thermogravimetric investigation to characterize the longtime behaviour of polymers are explained. Finally, general limitations of, and recommendations for, the application of TG, e.g. the combination with other methods of investigation, are mentioned. Thermogravimetrie (TG) und Differentialthermoanalyse (DTA) sind zwei seit langer Zeit angewandte Analysenmethoden. Ihre gemeinsame Behandlung im Rahmen dieser Arbeit ist insofern berechtigt, als beiden die Verfinderungen in der zu untersuchenden Probe in Abh/ingigkeit vonder linear ansteigenden Temperatur zugrunde liegen. Im Falle der Thermogravimetrie ergibt sich die Verfinderung des Probengewichts, im Falle der Differentialthermoanalyse die Ver~nderung der Enthalpie der Probe als abh/ingige Versuchsvariable. Ihre gemeinsarne Abh/ingigkeit vonder linear ansteigenden Temperatur fiihrt in neuerer Zeit mehr und mehr zur Konstruktion yon Ger/iten, die die genannten abhfingigen Parameter gleichzeitig registrieren. Die Thermogravimetrie und Differentialthermoanalyse waren ursprtinglich ffir die Untersuchung von Mineralien, Erzen, Tonen, analytischen Niederschl~ge usw. entwickelt worden. Ihr Einsatz in der Polymerforschung ist neueren Datums und man kann sagen, dab sic seit etwa 1960 zu einem unentbehrlichen Hilfsmittel ftir die Charakterisierung yon Polymeren in nahezu allen Forschungslaboratorien geworden sind. Die Zahl der Publikationen ist in den vergangenen 6-8 Jahren stark angestiegen [1 ] und es gibt heute wohl kaum ein organisches Polymeres, tiber das nicht thermogravimetrische oder differentialthermoanalytische Daten vorliegen. Inzwischen sind auch eine Reihe bemerkenswerter Monographien und {)bersichtsarbeiten erschienen [2-11] und die Thematik mehrerer Symposien und Tagungen wurde thermoanalytischen Problemen organischer hochmolekularer Verbindungen gewidmet [12,13].Hatte man zun~ichst von einer Vielzahl von Polymeren in zumeist empirischer Arbeitsweise die MSglichkeiten der thermoanalytischen Charakterisierung abge-