FIELD: chemistry.
SUBSTANCE: present invention relates to production of foamed vinyl aromatic polymers. The method of producing granules of fire-resistant foamed vinyl aromatic polymers, which enable to obtain foamed articles by aqueous suspension polymerisation, which includes polymerisation of styrene or a mixture of styrene and up to 25 wt % α-methylstyrene in an aqueous suspension in the presence of a peroxide initiating system which is active at temperature above 80°C, a foaming agent which is added before, during or after polymerisation, and in the presence of an amide of basic formula (I) R1CONHCH2 - CH2NHCOR2 (I), where R1 and R2, identical or different, denote an (iso)alkyl radical CH3(CH2)n for n ranging from 10 to 20, preferably from 16 to 18; and a fire-retardant system which includes a bromated additive with bromine content of more than 30 wt %, wherein said fire-retardant system includes bromated aliphatic, cycloaliphatic, aromatic compounds with bromine content of more than 30 wt %. Described is a foamed composition in form of granules based on vinyl aromatic polymers, which enables to obtain low-density foamed articles with improved insulating capacity, said composition including: a) a matrix obtained by polymerisation of styrene or a mixture of styrene and up to 25 wt % α-methylstyrene; b) 1-10 wt %, calculated with respect to the polymer matrix (a), foamed agent; c) 0.1-3 wt %, calculated with respect to the polymer matrix (a), self-extinguishing bromated additive in form of bromated aliphatic, cycloaliphatic, aromatic compounds with bromine content of more than 30 wt %; d) 0-1 wt %, calculated with respect to the polymer matrix (a), substance having synergetic effect, containing at least one C-C or C-O-O-C heat labile bond; e) 5-5000 mln-1, calculated with respect to the polymer matrix (a), amide of basic formula (I), obtained using the aqueous suspension polymerisation method described above. Also described is a foamed article, having thermal conductivity ranging from 34 to 36 mW/mK at 17 g/l, obtained by foaming and sintering granules based on a vinyl aromatic polymer composition described above.
EFFECT: obtaining foamed articles with low density and improved insulation capacity, and also resistant to deformations caused by solar radiation.
10 cl, 4 ex
