English to French Tech/Engineering Engineering (general) polymères

Bonjour
Dans des processus de polymérisation, comment traduire le terme 'endblocker' ?

The composition of claim 8 or claim 9, where the composition further comprises one or more additional ingredients, which are distinct from ingredients (A), (B), and (C), and which are selected from the group consisting of (D) a spacer; (E) an extender, a plasticizer, or a combination thereof; (F) a filler; (G) a filler treating agent; (H) a biocide; (I) a stabilizer, (J) a flame retardant; (K) a surface modifier; (L) a chain lengthener; (M) an endblocker;

Merci

Olivia