Construction of a copper hydroxystannate functionalized graphene oxide for rigid polyvinyl chloride foam toward improved fire safety

A copper hydroxystannate (CHS) functionalized graphene oxide (GO) (CHS@GO) was feasibly prepared through an in-situ method, and well characterized by TEM, XRD, FTIR and XPS. Rigid poly vinyl chloride (RPVC) foams containing CHS@GO were prepared by utilizing methyl hexahydrophthalic anhydride and isocyanate as coupling agents, azodiisobutyronitrile and azodicarbonamide as blowing agents. The fire safety, mechanical properties and thermal decomposition behavior of the RPVC foams were studied. The RPVC foam containing 2 wt% CHS@GO (RPVC/2CHS@GO) achieved a limiting oxygen index (LOI) of 35.5% and a V0 rating in the UL-94 tests. The cone calorimetric tests (CCT) results demonstrated the peak heat release rate (pHRR) and total heat release (THR) of RPVC/2CHS@GO were reduced by 40.6% and 36.8%, respectively, compared with those of pure RPVC foam (pure RPVC). The compressive strength and flexural strength of RPVC/2CHS@GO were increased by 47.3% and 34.6%, respectively, in contrast with those of Pure RPVC. The thermogravimetry results showed that CHS@GO endowed the RPVC foams with improved char residue.