CPC C08J 9/141 (2013.01) [B29C 44/3442 (2013.01); B29C 44/3465 (2013.01); B29C 44/36 (2013.01); C08J 9/0061 (2013.01); C08J 9/0066 (2013.01); C08J 9/16 (2013.01); C08J 9/18 (2013.01); C08J 9/232 (2013.01); C08K 3/04 (2013.01); C08J 2201/024 (2013.01); C08J 2201/03 (2013.01); C08J 2203/14 (2013.01); C08J 2325/04 (2013.01); C08J 2325/08 (2013.01); C08J 2453/00 (2013.01); C08J 2491/06 (2013.01)] | 12 Claims |
1. Expandable vinyl aromatic polymers comprising at least one blowing agent and a plurality of dispersed coke particles, said dispersed coke particles being characterized by:
(i) an average stack height (Lc) of carbon crystallites of at least 4 nm, wherein Lc is given by the formula
and is estimated from the full width at half maximum of diffraction peak [002];
(ii) a volume median particle diameter (D50) comprised between 1 and 5 μm, as obtained from laser light scattering measurements according to ISO 13320; and
(iii) a span (D90−D10)/D50 below 2.5 as obtained from laser light scattering measurements according to ISO 13320;
wherein the expandable vinyl aromatic polymers comprise between 4 and 6% by weight of the dispersed coke particles; and
wherein polymer foams obtained from the molding of expanded polymer pellets of the expandable vinyl aromatic polymers comprise a thermal conductivity, (λ), measured according to ISO 8301, of 31.0 mW/mK or less at a foam density of 12.5 kg/m3 or higher.
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