Halogen-free flame retardant poly (vinyl alcohol) foams prepared through thermal processing
writer：Dan Guo, Shibing Bai, Qi Wang
keywords：Halogen-free flame retardant foams, Poly (vinyl alcohol) foams, Extrusion foaming
source：会议
Issue time：2012年
Novel
halogen-free flame retardant PVA-based composite foams were successfully prepared
through continuous extrusion foaming using water as plasticizer and blowing
agent. The morphology, cellular structure and flame retardancy of
the prepared PVA foams were investigated. It was found that the halogen-free flame retardant containing
nitrogen-phosphorus (NPCs) were well dispersed in PVA matrix due to the strong interactions between the amino and hydroxyl groups
containing NCP molecules and the hydroxyl groups containing PVA molecules. The fine NCPs particles also acted as a good heterogeneous nucleating agent for
foaming. Combustion test showed that the prepared PVA foams had excellent flame
retardancy, its limiting oxygen index (LOI) reached up to 35% and passed the
UL94 V-0 rating test, and compared to the control sample, its peak heat release
rate (PHRR) declined, the temperature at the maximum peak heat release rate (TP)
shifted to higher temperature. Both
FT-IR and XPS analyses of the residual chars demonstrated that the catalytic
effect and chemical reactivity of the NPCs during the chars forming reactions
improved the flame retardancy of PVA foams.