Hybridization of α-zirconium phosphate with hexachlorocyclotriphosphazene and its application in the flame retardant poly(vinyl alcohol) composites

Abstract

A planar-like inorganic α-zirconium phosphate (α-ZrP) particles were modified by a kind of cyclophosphazene derivative via three-step hybridization method, first modified by melamine (MA), then combined with hexachlorocyclotriphosphazene (HCCP) through nucleophilic substitution and further integrated with excessive MA. Thus, a hybrid flame retardant (HAC) was successfully synthesized. The composites based on poly(vinyl alcohol) (PVA) and HAC were prepared by solution blending. The thermal, mechanical properties and flame retardancy of the composites were studied. It was found that HAC showed a catalytic effect in the initial decomposition stage and promoted the formation of char at high temperatures. When the content of HAC was 15 wt%, the limiting oxygen index (LOI) reached 28.4% and classified V-0 rating, whereas with the same content of fire retardant, for PVA/α-ZrP and PVA/product of MA with HCCP composites (one kind of intumescent flame retardant IFR), the LOI values were only 24.7% and 27.1%, respectively. The combination of IFR and α-ZrP could remarkably improve the yield and graphitization of char residues, make the char more stable, compact and continuous, inhibiting underlying PVA from contacting heat and oxygen. Moreover, the mechanical properties could be reinforced and toughened with certain content of HAC.

Preparation of hexakis (4‐aldehyde phenoxy) cyclotriphosphazene grafted kaolinite and its synergistic fire resistance in poly (butylene succinate)

“…But the wide absorption ranges around 3200/cm for ─OH group almost disappear in HAPCP. At the same time, the two peaks at 523 and 601/cm for P─Cl group in HCCP are also disappeared in HAPCP. The almost disappearance of ─OH and P─Cl peaks indicates the reaction between ─OH and P─Cl groups.…”

Synthesis of bio‐based poly (cyclotriphosphazene‐resveratrol) microspheres acting as both flame retardant and reinforcing agent to epoxy resin

“…As can be seen, the peaks at 1604 and 1504 cm −1 correspond with the characteristic absorption of benzene ring appearing in REV and PRV. Banks at 862 and 963 cm −1 is ascribed to the P─N and P═N 20, stretching presented in HCCP and PRV. Furthermore, a new characteristic absorption peak appears at 1189 cm −1 (P─OPh), indicating that P─Cl on HCCP reacted with the hydroxyl group on REV.…”

Effect of different ionic layered compounds decorated with zinc hydroxystannate on flame retardancy and smoke performance of epoxy resin

“…The level of residue char graphitized is usually indicated by the I D /I G , the ratio of D band to the G band. In the combustion process, the high graphitization means a good effect to hinder mass and heat transfer, and the higher the ratio is, the higher the graphitization degree of carbon residue will be . As can be seen from Figure , the I D /I G value of pure EP is 2.49, and the I D /I G value of the EP composites is reduced to different degrees after the addition of different flame retardants.…”

“…Xu et al also synthesized functional α‐ZrP (HCA‐α‐ZrP) and prepared PVA composite by adding HCA‐α‐ZrP to polyvinyl alcohol (PVA). Their results showed that HCA‐α‐ZrP helps to reduce the fire hazard of PVA composite with an evident effect, and the LOI value of PVA composite added with 3 wt% HCA‐α‐ZrP reached 28.4% …”