Thermal Analysis of Polymers. Part 5: DSC and TGA of Elastomers - METTLER TOLEDO

Thermal Analysis of Polymers. Part 5: DSC and TGA of Elastomers

Glass Transition of EPDMFigure 1: Determination of the glass transition temperature of two samples of unvulcanized EPDM with different ethylene contents.

The previous UserCom articles on the thermal analysis of polymers [1, 2, 3, 4] presented an overview of the four main thermal analysis techniques, DSC, TGA, TMA, and DMA, and the possibilities they offer for the analysis of thermoplastics and thermosets. This article deals with the thermal analysis of elastomers [5, 6] and covers the properties of elastomers that can be characterized by DSC and TGA. A future article (Part 6) will describe TMA and DMA applications. The elastomers used for the experiments were EPDM (ethylenepropylene- diene rubber), SBR (styrene-butadiene rubber), NBR (natural butadiene rubber) and EVA (ethylene-vinylacetate copolymer).


Introduction

Elastomers is the name given to a group of lightly-crosslinked polymers that exhibit elastic or viscoelastic deformation. Thermal analysis plays an important role in the analysis of elastomers. It is widely used to characterize raw materials, intermediate products and vulcanization products. The information obtained is valuable for quality control, process optimization, research and development of advanced materials, and failure analysis.

This article discusses physical properties and chemical reactions that are typical and important for elastomers. The properties include the glass transition temperature, melting, vulcanization, compositional analysis, fillers and additives, creep and recovery, master curve and compatibility of polymer blends.

The elastomers used in experiments to illustrate these properties were EPDM (ethylene-propylene-diene rubber), SBR (styrene-butadiene rubber), NBR (natural butadiene rubber) and EVA (ethylenevinyl acetate copolymer).


Experimental details

The measurements were performed using the following METTLER TOLEDO instruments: DSC 1 with FRS5 sensor; TGA/DSC 1; TMA/SDTA840e and 841e; and DMA/SDTA861e.

Details of the samples and experimental conditions are described in the individual applications.



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This article series will be continued in UserCom36 and complemented with TMA and DMA measurements.



Thermal Analysis of Polymers. Part 5: DSC and TGA of Elastomers | Thermal Analysis Application No. UC351 | Application published in METTLER TOLEDO Thermal Analysis UserCom 35