From Polymer Reference Book

Two techniques, dynamic mechanical thermal analysis (DMTA) and dielectric thermal analysis (DETA), have been used for the study of resin cure. Differential scanning calorimetry (DSC) has also been employed (for a discussion of the theory and instrumentation of DSC, see Chapter 9). The application of differential photocalorimetry to the measurement of cure rates of photocurable resins is discussed in Chapter 12.

10.1 Dynamic Mechanical Thermal Analysis

10.1.1 Theory

Although DMTA has found its major applications in the mechanical testing of plastics (see Chapter 15), it has also found application in degradation studies, chemical reaction studies such as resin curing measurements (i.e., degree and rate of cure), and studies of temperature properties of elastomers.

In resin cure studies the technique characterises the rheological changes in resins before, during, and after cure. Plots of temperature versus permittivity pinpoint the glass transition temperature (T g) for the resin during cure. Plots of time versus logarithm of loss factor enable determinations of vitrification of resins during cure to be carried out.

The rheological changes in a polymer during complex thermal histories can provide information about polymer processing, chemical structure, and end-use performance (time or temperature versus logarithm of loss factor, time versus logarithm of conductivity, and temperature permittivity plots).

10.1.2 Instrumentation

Some available instrumentation and software for DMTA is listed next (see also Appendix 1):

  • Perkin Elmer: Series 7, Model DMA-7

  • DuPont: 9000 Thermal Analysis System, Model 983

  • PL Thermal Sciences: Model PL DMA

  • TA Instruments: Model DMA 983

10.1.3 Applications

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Products & Services
Polymer Concrete and Mortar
Polymer concrete and mortar are binders, compounds, and aggregate mixtures that use epoxy, polyester, vinyl ester or other polymer resin bonds. They cure or set through chemical reactions, thermoset bonds, and multiple component binder systems.
Conductive Compounds
Conductive compounds provide an electrically and/or thermally conductive path between components.
Specialty Cement, Concrete, and Mortar
Specialty cement, concrete and mortar contain specialized binders such as K silicate, calcium aluminate, sulfur, and oxysulfate or polymer resins. They cure or set through film drying (air setting), chemical reactions, thermoset bonds, hydraulic bonds, hot melting, and multiple component binder systems.
Electrical and Electronic Resins
Electrical and electronic resins includes adhesives, greases, pads, stock shapes, tapes, encapsulants, potting compounds, thermal interface materials, and electrically conductive substances used in electrical, electronics, and semiconductor applications.
Industrial Sealants
Industrial sealants are liquid or viscous compounds used between surfaces to contain fluids, prevent leaks, and prevent infiltration of unwanted material. They may also include compounds for filling gaps or seams.

Topics of Interest

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AA Atomic absorption AAS Atomic absorption spectrometry/spectrometers ABS Acrylonitrile butadiene styrene terpolymers ADC Analogue-to-digital converter AES Auger electron spectroscopy AFM...

ac Alternating current AFM Atomic force microscopy AR Acrylic resin ASTM American Society for Testing and Materials au Arbitrary units BaH Barium hexaferrite BAS Bulgarian Academy of...