Characterization of thermo-physical properties of EVA/ATH : Application to gasification experiments and pyrolysis modeling

• The pyrolysis of solid polymeric materials is a complex process that involves both chemical and physical phenomena such as phase transitions, chemical reactions, heat transfer, and mass transport of gaseous components. For modeling purposes, it is important to characterize and to quantify the properties driving those phenomena, especially in the case of flame-retarded materials. In this study, protocols have been developed to characterize the thermal conductivity and the heat capacity of an ethylene-vinyl acetate copolymer (EVA) flame retarded with aluminum tri-hydroxide (ATH). These properties were measured for the various species identified across the decomposition of the material. Namely, the thermal conductivity was found to decrease as a function of temperature before decomposition whereas the ceramic residue obtained after the decomposition at the steady state exhibits a thermal conductivity as low as 0.2 W/m/K. The heat capacity of the material was also investigated using both isothermal modulated Differential Scanning Calorimetry (DSC) and the standard method (ASTM E1269). It was shown that the final residue exhibits a similar behavior to alumina, which is consistent with the decomposition pathway of EVA/ATH. Besides, the two experimental approaches give similar results over the whole range of temperatures. Moreover, the optical properties before decomposition and the heat capacity of the decomposition gases were also analyzed. Those properties were then used as input data for a pyrolysis model in order to predict gasification experiments. Mass losses of gasification experiments were well predicted, thus validating the characterization of the thermo-physical properties of the material. © 2015 by the authors; licensee MDPI, Basel, Switzerland.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Samhällsbyggnadsteknik -- Husbyggnad (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Civil Engineering -- Building Technologies (hsv//eng)

Nyckelord

Aluminum tri-hydroxide

Ethylene vinyl acetate copolymer

Gasification

Heat capacity

Pyrolysis modelling

Thermal conductivity

Alumina

Aluminum

Capillary flow

Characterization

Cracking (chemical)

Decomposition

Differential scanning calorimetry

Ethylene

Heat transfer

Hydrophobicity

Optical properties

Organometallics

Physical properties

Polyvinyl acetates

Specific heat

Thermoplastic elastomers

Complex Processes

Decomposition gas

Decomposition pathway

Experimental approaches

Modulated differential scanning calorimetry

Physical phenomena

Thermo-physical property

Steel Structures

Publikations- och innehållstyp

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