Gel Permeation Chromatography (GPC) —
A size exclusion technique that measures the molecular weight and weight distribution of most polymers. GPC is the most accurate way to quantify degradation. It is also very useful in identifying additives, modifiers, and low level impurities and can be used to estimate a polymer's physical properties.

Thermogravimetric Analysis (TGA) —
A thermal analysis procedure that measures weight loss as a function of temperature in a controlled environment. The temperature points at which active components volatilize are plotted, creating a graph that quantifies the composition.

Microstructural Analysis —
A failure analysis technique that involves the observation of a thin cross section of a sample under a compound polarizing light microscope. A trained eye can detect patterns of stress, irregularities in the microstructure, contaminants, voids, and design flaws. An integral, high-resolution camera provides a permanent record of the evaluation.

Differential Scanning Calorimetry (DSC) —
A thermal analysis procedure that measures the rate of heat flow. DSC charts the difference between the rate of the test sample and that of a known reference material. This difference is useful in determining variations in composition and in measuring the degree of crystallinity and oxidation.

Fourier Transform Infrared Spectrometry (FTIR) —
Defines the chemical composition of a sample by the amount of infrared light that is transmitted through or absorbed by the sample. The resulting computerized analysis is used to identify resins, to identify and quantify additives, and to determine the presence of copolymers.

Ash Content (burn-off testing) —
A direct procedure for isolating non-combustible elements, such as glass and minerals, in a resin sample. The resin is burned off, leaving the identifiable and measurable inorganic material.

Melt Flow Rate —
Measures the viscosity of a polymer through a defined orifice at a constant temperature. Differences in these rates are used to flag lot-to-lot variations and to detect degradation caused by processing.

Relative Viscosity —
Measures the viscosity of a polymer through dilute solution methodology. Incoming quality assessments as well as degradation determinations can be made with this technique.