Struktol KW 400 Fatty acid esters Struktol Plasticizers Rubber - Elastomer (Chloroprene, Butyl …) STRUKTOL ® KW 400 PLASTICIZERS Synthetic or fatty acid esters. STRUKTOL ® ester plasticizers are special purpose synthetic plasticizers mainly used in compounds based on nitrile rubber. The decreased raw compound viscosity facilitates further processing. STRUKTOL ® KW 400 will improve the low temperature flexibility with all commonly used rubbers. For example, NBR vulcanizates can be compounded with flexibility at temperatures as low as -55 o C. STRUKTOL ® KW 400 is easily soluble in aliphatic and aromatic hydrocarbons. STRUKTOL ® KW 400: 0.5 - 40 phr Fatty acid ester. Used as a plasticizer in nitrile rubber compounds. Provides low surface resistance. Improves low temperature flexibility. Use level: 0.5-40 phr.