Thermal analysis applied to the characterization of degradation in soil of polylactide : II. on the thermal stability and thermal decomposition kinetics

• The disposal stage of polylactide (PLA) was assessed by burying it in active soil following an international standard. Degradation in soil promotes physical and chemical changes in the polylactide properties. The characterization of the extent of degradation underwent by PLA was carried out by using Thermal Analysis techniques. In this paper, studies on the thermal stability and the thermal decomposition kinetics were performed in order to assess the degradation process of a commercial PLA submitted to an accelerated soil burial test by means of multi-linear-non-isothermal thermogravimetric analyses. Results have been correlated to changes in molecular weight, showing the same evolution as that described by the parameters of thermal stability temperatures and apparent activation energies. The decomposition reactions can be described by two competitive different mechanisms: Nucleation model (A2) and Reaction Contracting Volume model (R3). The changes in the kinetic parameters and kinetic models are in agreement with the calorimetric and dynamic-mechanical-thermal results, presented in the Part I of the study [1]. © 2010 Elsevier Ltd. All rights reserved.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Kemiteknik -- Polymerteknologi (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Chemical Engineering -- Polymer Technologies (hsv//eng)

Nyckelord

Degradation in soil

Isoconversional methods

Polylactide

Thermal decomposition kinetic analysis

Active soils

Apparent activation energy

Chemical change

Decomposition reaction

Degradation process

Different mechanisms

International standards

Iso-conversional method

Kinetic models

Nonisothermal

Nucleation models

Poly lactide

Polylactides

Soil burial test

Thermal analysis

Thermal analysis techniques

Thermal decomposition kinetics

Thermal stability

Volume models

Activation energy

Degradation

Pyrolysis

Reaction kinetics

Soils

Thermodynamic stability

Thermogravimetric analysis

Soil testing

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)