FIELD: chemistry.
SUBSTANCE: invention relates to an improved composition for production of vinyl aromatic polymers, modified rubber, where considerable improvement of impact strength of end product is caused by inclusion of a modifying additive structure at different stages of polymerisation, preferably during combined continuous phase and, in particular, on interval treatment phases. Additive is a compound of formula: 
where each R1, R3 is saturated or unsaturated chain of C1-C18, where R1 and R3 are identical or differ from each other, each of R2, R4, R5 denotes hydrogen, halogen or carbonised circuit consisting of C1-C18, where R2, R4, R5 are identical or differ from each other, R6 denotes a C2H4 group, n is an integer equal to or greater than 1.
EFFECT: significant improvement of impact strength of vinyl aromatic polymers.
13 cl, 7 dwg, 2 tbl, 3 ex
