STP1136: Material Characterization by Thermomechanical Analysis: Industrial Applications

    Riga, AT
    Senior research chemist and corporate consultant, Lubrizol Corporation, Wickliffe, OH

    Collins, EA
    Senior research chemist and corporate consultant, Lubrizol Corporation, Wickliffe, OH

    Pages: 13    Published: Jan 1991


    Abstract

    Thermomechanical analysis (TMA) has been used to study a wide spectrum of materials over a broad range of temperatures in our laboratories. Polymers, motor oil-wax composites, ceramics, alloys, and metals have been studied from -100 to 600°C. The TMA properties that have been measured are the glass transition temperature, softening point, coefficients of linear expansion, heat deflection temperatures, creep modulus (compliance) and relaxation, degree of cure, viscoelastic behavior, dilatometric properties, melting temperature, Curie, and Neel magnetic transition temperatures and properties.

    Polymer cure has been studied and is indicated by variations in the glass transition temperature and increased with heat cycling. A good correlation exists between ASTM Vicat softening temperatures and heat deflection temperatures under load with TMA transition temperatures, which approximate strength and Tg. A scheme has been developed to rank commercial polymers based on their creep modulus and creep recovery. There is a good correlation between the TMA creep properties and the known tensile properties of commercial polymers.

    Additive-treated oil forms short stubby wax crystals, which lead to a low creep modulus oil-wax composite at -60°C. This soft composite (gel) melts at a depressed temperature. These TMA properties have been related to low-temperature pumpability and engine performance.

    The critical magnetic transition temperatures (Curie and Neel) of a number of ceramics and alloys have been determined by TMA. There is a good correlation between the TMA, differential scanning calorimetry (DSC), and literature critical magnetic temperatures. The mechanism responsible for magnetic changes in the paramagnetic state has been elucidated from TMA expansion rates and DSC exothermicity.

    Keywords:

    Thermomechanical analysis, industrial applications, polymers, composites, ceramics, alloys, metals, temperatures


    Paper ID: STP23592S

    Committee/Subcommittee: E37.01

    DOI: 10.1520/STP23592S


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