Citriflex 84: bio-based plasticizer for PVC and elastomers

Phthalate plasticizers have been the workhorses of PVC flexibility since the 1930s. They are effective, low-cost, and abundant, and under increasing regulatory scrutiny. DEHP, DBP, and BBP are restricted under EU REACH, California Prop 65, and CPSC regulations for children's products, and the list of regulated phthalates continues to grow. Citrate esters have established themselves as the most commercially viable alternative for demanding applications.

Citriflex 84 (acetyl tributyl citrate, or ATBC) is among the most widely used citrate ester plasticizers, combining low volatility, strong compatibility, and a bio-based carbon content that supports sustainability positioning.

Properties of Citriflex 84 (ATBC)

ATBC is produced by esterification of citric acid (a naturally occurring tricarboxylic acid derived from fermentation of sugars) with butanol, followed by acetylation. Main characteristics:

• Low volatility: significantly lower than comparably performing phthalate plasticizers, resulting in improved heat aging and reduced weight loss in service
• Good plasticizing efficiency: achieves target flexibility at reasonable loading levels in PVC and nitrocellulose systems
• FDA compliance: acceptable for food contact, medical device, and pharmaceutical packaging applications
• Bio-based content: citric acid feedstock is derived from fermentation, giving ATBC a measurable bio-based carbon content by ASTM D6866

Key applications

• Food packaging PVC films: cling wraps, lidding films, and food service applications requiring FDA compliance
• Medical device PVC: blood bags, IV tubing, and medical packaging where DEHP restrictions apply
• Children's product PVC: toys and juvenile products regulated under CPSC and EU toy safety directives
• Nitrocellulose lacquers: where low volatility and film flexibility are required
• Personal care: as a solvent and plasticizer in nail polish, tablet coatings, and topical formulations