Rasvasel

Rasvasel is a viscous, oil-like liquid used primarily as a plasticizer and lubricant in polymer formulations. It is typically a mixture of fatty acid esters and polyol esters, selected for its ability to impart flexibility to plastics without excessive volatility. The term appears in industrial datasheets and regulatory documents describing biobased or low-toxicity plasticizers.

Rasvasel is produced by transesterification of triglycerides derived from vegetable oils or animal fats with short-chain alcohols, followed by purification to remove impurities. The resulting esters vary in chain length and branching, which influences viscosity, compatibility with polymers, and volatility. Some formulations include stabilizers to limit oxidation and odor.

Its physical properties depend on the composition but generally include a high boiling point, low vapor pressure, and good compatibility with polymers such as polyolefins. Rasvasel tends to be colorless to pale yellow and can be a clear liquid or semi-solid at room temperature. It remains primarily immiscible with water but is soluble in many organic solvents, and its miscibility with specific polymers can be tuned through formulation.

Common applications include flexible film packaging, adhesives, sealants, and coatings where reduced brittleness and improved processability are desired. In addition, rasvasel can serve as a secondary lubricant in metalworking and machinery where incidental contact with polymers occurs.

Safety and regulatory status vary by jurisdiction. Rasvasel-based products are often marketed as low-toxicity or biobased, but standard assessments for plasticizers apply, including tests for migration, skin contact, and environmental persistence. Some fatty acid ester plasticizers have raised concerns about long-term health effects, necessitating compliance with applicable regulations. See also: plasticizer, ester, fatty acid ester, polymer additive.