Polymer off-gassing refers to the release of volatile compounds from a material into the surrounding air. This process is commonly noticed as a persistent chemical odour from newly manufactured parts. Off-gassing can occur for several reasons, depending on the material formulation, manufacturing process, and environmental conditions.
Common off-gassing mechanisms include:
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Physical evaporation of volatile components retained within the polymer matrix, such as residual solvents, impurities, oligomers, or additives.
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Surface evaporation of solvents remaining on the exterior of a part, similar to the drying process of paints or coatings.
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Slow chemical reactions within the polymer, including continued curing or polycondensation after manufacturing.
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Surface degradation processes, such as hydrolysis, oxidation, or biodegradation resulting from interaction with air and its components.
Off-gassing tests can be conducted over 6, 30, or 55 hours at either ambient or elevated temperatures. The relative humidity of the test air can be controlled from dry conditions (0% RH) to ambient levels and up to 80% RH. Samples may be tested in their commercial form or as dust. Emitted gases and vapours can be measured as total vapours or as individual chemical compounds. When the composition of emissions is unknown, analytical identification of individual components can be performed.
Several testing approaches are available, each addressing off-gassing from a different analytical perspective:
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Off-gassing screening using Total Volatile Organic Compounds (TVOC) measured by photoionization detection (PID).
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Open characterization of off-gassing products, performed as an add-on to TVOC-PID screening using GC MS
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Detailed off-gassing studies, involving time-resolved monitoring of specific organic and inorganic compounds emitted by the polymer.
LCS Laboratory has more than 20 years of experience in analytical chemistry and air testing, with ongoing work in manufacturing, construction materials, consumer products, and industrial process evaluation. The laboratory is equipped with controlled-environment test chambers, precise temperature and humidity control, and a range of analytical instruments suitable for both screening-level and compound-specific analysis of gases and vapours.
Testing programs are typically adapted to the client’s product, expected use conditions, and project objectives. Please contact us to discuss their materials, performance concerns, and the most appropriate testing approach for their application. ©
