Layer　by　layer　(LBL)　self-assembly　coatings　upon　expandable　polystyrene　(EPS)　surface　play　an　important　role　in　improving　its　flame　retardancy.　However,　a　large　number　of　layers　is　needed　to　achieve　a　satisfied　fire　performance,　and　the　coatings　are　difficult　to　adhere　on　the　inert　EPS　surface,　resulting　in　the　poor　durability.　In　this　work,　the　surface　of　EPS　was　activated　by　ultraviolet　ozone　(UVO)　with　the　appearance　of　oxygen　contained　groups,　then　a　LBL　coating　with　only　two　bilayers　(branched　polyethyleneimine　(BPEI)-kaolinite　(kaol)-BPEI-diethylene　triamine　penta　(methylene　phosphonic　acid))　was　covalently　connected　on　the　EPS　surface.　Compared　with　neat　EPS,　the　obtained　E-K5D30　sample　increased　the　value　of　limiting　oxygen　index　(LOI)　from　18.8　%　to　37.7　%,　improved　the　ignition　time　from　59　s　to　95　s,　reduced　the　peak　heat　release　rate　(pHRR)　value　from　282.0　kW/m2　to　220.9　kW/m2,　and　enhanced　the　char　residues　from　6.3　%　to　32.3　%　after　the　combustion.　Moreover,　an　ultraviolet　(UV)　curing　layer　with　P/N　elements　was　prepared　upon　E-K5D30　sample　to　maximize　the　flame　retardant　durability.　A　novel　amino-intercalated　kaol　was　used　to　play　a　smoke　suppression　role.　The　results　showed　that　E-K*5D30-P8N3　sample　further　increased　the　LOI　to　39.2　%.　Even　after　12　h　washing,　the　E-K*5D30-P8N3　sample　exhibited　a　slight　LOI　reduction　to　37.8　%,　and　fire　performance　index　(FPI)　value　of　0.405　m2·s/kW,　showing　the　successful　construction　of　coatings　with　good　fire　safety　and　flame　retardant　durability.　©　2024　Elsevier　B.V.