Test Methods

Abstract

Plastics testing covers analytical, thermal, physical, and environmental procedures for determining the composition, structure, as well as mechanical and other responses to a variety of environmental conditions of plastic materials. General uses of Fourier transform infrared, nuclear magnetic resonance, Raman, and X‐ray techniques are reviewed and illustrated with specific examples. Developments in neutron and X‐ray scattering techniques, as well as molecular weight determination techniques such as gel‐permeation chromatography and turbidimetric methods, are also covered. Thermal tests, thermogravimetric analysis, differential thermal analysis, differential scanning calorimetry, and dynamic mechanical analysis are all useful for understanding degradation and phase changes in polymers and their influence on material behavior. New techniques of atomic force microscopy and positron annihilation are allowing studies of the microstructure of polymers and free volume determinations. Several mechanical testing techniques are used in plastics for normal quality control testing and initial application screening of polymers. These tests and those used for more fundamental understanding of polymer response to stress, including fracture mechanics procedures, are referenced. Flammability tests commonly used for plastics include oxygen index, flammability ratings, and smoke generation. Work on the use of cone calorimeters to characterize behavior of plastics under fire conditions is also covered. Finally, environmental testing, chemical exposure, weathering, radiation, and biological agents are reviewed. Emphasis is given to test development or applications reported since 1990.

Polymer Fracture

“…These relations are also helpful in context with other key subjects within this Encyclopedia: Fracture Mechanics necessarily appears as part of the important mechanical characterization methods (80) as well as in a discussion of impact behavior (81).…”

Chemometric Methods for Estimating the Strain Hardening Modulus in Polyethylene Resins

“…Over the past decade, the ability to characterize polymer composition has dramatically improved with advances in analytical methods. 1–4 Specifically, the development of chromatographic systems with multivariable detectors can provide a variety of structural information dependent upon the type of detector used and can help to discern the underlying polymer microstructure. Furthermore, chromatographic systems that couple two different types of separation methods such as liquid (high-performance liquid chromatography [HPLC]) and size exclusion chromatography (SEC) or couple temperature with SEC analytical temperature rising elution fractionation (ATR EF-SEC), have afforded even greater insight into the composition of various polymers by providing multidimensional data.…”