Polyolefin Non Intentionally Added Substances Identification Basics
Polyolefin non-intentionally added substances require chromatographic screening, Cramer toxicological tiering, and finished article migration verification.
Erucamide Breakdown Products
Meaning
Volatile chemicals produced during the thermal oxidation of slip agents can negatively impact the quality of plastic films and parts. These erucamide breakdown products form when the primary additive is exposed to high temperatures or UV light for extended periods. While erucamide is added to reduce the coefficient of friction, its degradation can lead to surface defects and unintended odors.
Degradation Pathway
Heat and oxygen react with the unsaturated carbon bonds in the amide molecule. This process results in the formation of various erucamide breakdown products such as ketones and carboxylic acids. Because these molecules are often more mobile than the original slip agent, they can migrate to the surface at unpredictable rates.
Surface Appearance
Accumulation of these degraded molecules often creates a hazy or yellowish film on the surface of clear parts. This phenomenon is distinct from the normal blooming of the slip agent, as the erucamide breakdown products do not provide the desired lubricity and instead create a sticky or uneven texture. In high precision optical or medical components, this surface contamination can render the part unusable.
Olfactory Profile
Sharp or rancid smells in a resin batch often indicate the presence of these oxidative byproducts. Because erucamide breakdown products have a much lower sensory threshold than the original additive, even small amounts can cause a shipment to be rejected for use in food or water packaging. Maintaining tight control over processing temperatures and minimizing the time the resin spends in a molten state are the most effective ways to prevent the development of these unwanted chemicals.