FIELD: chemistry.
SUBSTANCE: invention relates to a foamed polymer composition with a high foaming degree, excellent stability of a cellular structure and an end product. Described is a foamed polymer composition in the form of balls with processing properties, including i) a polymer base, ii) from 0.2 to 10 pts. wt. foaming agent in terms of 100 parts of polymer base (i) and iii) additive with plasticizing effect. Polymer base i) consists of a) 0 to 100 wt. % of vinyl aromatic polymer in terms of total weight of base (i), b) from 100 to 0 wt. %, based on the total weight of the base (i) of the copolymer, containing from 50 to 99 wt. % vinyl aromatic monomers and from 1 to 50 wt. % of at least one type of alkyl ester, containing from 1 to 18 carbon atoms and being a derivative of acrylic or methacrylic acid, wherein polymer base contains at least 2 wt. % of component (b) or polymer base contains only component (a). Additive with plasticizing effect is used in quantity A) from 0 to 10 pts. wt. in terms of 100 parts of polymer base (i), if (i) contains at least 2 wt. % of component (b), or B) from 0.3 to 10 pts. wt. in terms of 100 parts of polymer base (i) if (i) contains only component (a). Said polymer composition is characterized by that molecular weight Mp maximum peak of base (i) is from 130 to 190 kDa, and obtained during centrifugation average molecular weight Mz base (i) ranges from 430 to 900 kDa, and the glass transition temperature difference (DTg) of vinyl aromatic polymer of comparison and glass transition temperature of polymer composition, consisting of said base (i) and optionally component (iii), is in range from 1 to 8 °C. Vinyl aromatic polymer has a molecular weight distribution (MWD) of the base (i) and a composition corresponding to the vinylaromatic fraction of the base (i), wherein said molecular weights and molecular weight distribution are determined by the method of exclusion chromatography.
EFFECT: technical result is providing a polymer composition in the form of beads with high degrees of pre-foaming without premature collapse of the cellular structure and with excellent stability of the cellular structure, which increases efficiency of methods for manufacturing foamed articles, reduces costs and reduces emissions of volatile organic substances into atmosphere.
13 cl, 11 ex, 6 tbl
