FIELD: chemistry; expandable vinyl aromatic polymers.
SUBSTANCE: description is given of the expandable vinyl aromatic polymers, which consist of a) a matrix, obtained through polymerisation of 50-100% of mass of one or more vinyl aromatic monomers and 0-50% mass of a monomer, capable of co polymerisation; b) 1-10% mass, estimated for polymer (a), of the expanding agent in the polymer matrix; c) 0.01-20% mass, estimated for polymer (a), of soot, homogenously distributed in the polymer matrix, with average diameter in the interval from 30 to 2000 nm, surface area from 5 to 40 m2/g, sulphur content from 0.1-2000 million parts and ash content from 0.001 to 1%. Description is also given of expandable products, which can be obtained from the above mentioned expandable vinyl aromatic polymers, with density in the interval from 5 to 10g/l and thermal conductivity from 25 to 50 mW/mK, more than 10% lower than the same value for similar expanding materials without soot. Description is also given of the method of making expandable vinyl aromatic polymers. The method involves polymerisation in a water suspension of one or more vinyl aromatic monomers, possibly together with at least, one monomer, capable of copolymerisation, in quantity of 50% mass, in the presence of soot, with average diameter in the interval from 30 to 2000 nm, surface area from 5 to 40 m2/g, sulphur content from 0.1 to 2000 million parts and ash content from 0.001 to 1%, and in the presence of a peroxide radical indicator, possibly containing at least, one aromatic ring, and an expanding agent, added before, during or at the end of polymerisation. A method of continuous obtaining of expanded vinyl aromatic polymers is also described.
EFFECT: obtaining of vinyl aromatic polymers, which have lower thermal conductivity and density after expansion.
21 cl, 8 ex
