Synthesis Of Intumescent Flame Retardant With Inverse Suspension Polymerization And Properties Of Flame Retardant SBR

In this paper, melamine-formaldehyde resin was prepared in inverse suspensionpolymerization way, together the components (ammonium-polyphosphate APP,pentaerythritol PET) of intumescent flame retardant (IFR) system were wrapped insitu to prepare IFR powder, the factors that may affect the stability of the inversesuspension polymerization system were discussed; the flame-retardant effect of themass ratio between the components was investigated. Then IFR was applied instyrene-butadiene rubber (SBR) and the flame retardant property and physicalperformance of the vulcanized rubber SBR/IFR were researched, finally the burningcarbon layer and the thermal properties of the vulcanized rubber SBR/IFR werestudied by scanning electron microscopy (SEM) and TG-FTIR. The followingconclusions can be attained through the experiment tests and analysis.The study of mass ratio between the components showed that when theamount of MEL was3wt%possession of IFR and the ratio of APP: PER wasbetween4to5.67, gave the highest residual carbon rate. Scanning electronmicroscopy (SEM) results showed that IFR with higher residual carbon rate hadmore homogeneous and thick foam wall. The conditions of stable inverse suspensionpolymerization system were determined and IFR powder was prepared. The IRanalysis of IFR showed that melamine-formaldehyde resin was synthesized and IFRpowder with APP and PER wrapped by it was prepared. The SEM results of IFRshowed that the size of IFR powder mainly in the vicinity of0.5μm and the particlewas regular sphere.The physical and mechanical properties of vulcanized rubber SBR/IFRdemonstrated that with the growing amount of IFR, the tensile strength and tearstrength of SBR/IFR increased, while the hardness and rebound elasticity decreased. The analysis of oxygen index of SBR/IFR showed that SBR/IFR had acorresponding improvement in flame retardant properties, its oxygen index improvedsignificantly, and when the dosage of IFR was30wt%, its oxygen index can get to27.7. Through the thermal analysis of SBR/IFR investigated by TGA demonstratedthat compared with SBR, vulcanized rubber SBR/IFR can form stable expansioncarbon layer after burning and had better thermal stability. Finally, the cross-sectionand residual carbon morphology of SBR/IFR were observed by SEM, the resultsshowed that IFR powder had good dispersion and compatibility with rubber. Afterburning, the residual carbon surface of the sample SBR/IFR (30wt%) was compact,forming uniform small room as honeycomb, which was almost a closed structure,blocking the transfer of oxygen and heat effectively and preventing the escape ofbiodegradable gas.