Recently ASTM D 4065-82 (Practice for Determining and Reporting Dynamic Mechanical Properties of Plastics) was written to provide important rheological information on thermoplastics and thermosetting resins/reinforced plastics-composites. These procedures have been established for monitoring the subtleties of macromolecular behavior, the effects of processing, and in-service performance.
The significance of ASTM D 4065-82 is the generation of important rheological information that can be used to organize, monitor, and provide the necessary information for the quality control and assurance engineer.
Dynamic mechanical testing (DMT) of polymeric material systems provides important viscoelastic information for the materials, design, and process engineer. DMT quickly generates the critical information the materials engineer needs for formulating new composite systems, especially as raw material prices change. The design engineer will use DMT results for optimizing functional performance with greater reliability. The processing engineer will use DMT for assessing the effects of processing parameters on functional performance and determining the effect of changes in temperature on modulus, impact, and dimensional stability.
DMT provides critical information on the effects of the environment, such as moisture on long-term durability. Short-term dynamic mechanical characterizations can be used to establish “master curves” for predicting time-dependent behavior.
Representative examples of DMT as a function of frequency (dynamic oscillation), strain, temperature, and time are cited to illustrate how ASTM D 4065-82 is being used as an effective analytical procedure for ensuring quality and for predicting long-term functional performance. The final section of this paper details the use of instrumented impact testing [ASTM D 3763-79 (Test Method for High-Speed Puncture Properties of Rigid Plastics)] for generating additional information on functional performance.