Modification of poly(styrene-block-butadiene-block-styrene) [SBS] with phosphorus containing fire retardants

Abstract

a b s t r a c tAn elaborate survey of the chemical modification methods for endowing highly flammable SBS with increased fire resistant properties by means of chemical modification of the polymer backbone with phosphorus containing fire retardant species is presented. Optimal conditions for free radical addition of the PAH containing fire retardants to a double bonds of poly(butadiene) block of SBS were found, affording varied degree of the modification (0.2-21 mol%). Alternatively, a two-step procedure based on an epoxidation step followed by hydrolysis of the epoxides with phosphoric acid was developed resulting in 20 mol% of poly(butadiene) block modification. Based on TGA results, organophosporus-modified SBS was found to be amenable to charring -a property which correlated directly with the reduced flammability of the modified polymer observed in Cone Calorimetry tests. Furthermore, conceptually novel application of the H 3 PO 4 modified SBS as a fire retardant additive for bitumen material, in combination with synergetic melamine species, offered 25% better self-extinguishing properties of such formulation already at a low loading level of the fire retardant components (3.5 wt.%).

Hydrogen bonding and thermoplastic elastomers – a nice couple with temperature-adjustable mechanical properties

“…This offers the possibility to tune the properties of the polymer [23][24][25][26][27] and thus widens the range of potential applications eminently. 26,[28][29][30][31] For instance, the combination of thermoplastic polystyrene and elastomeric polybutadiene provides thermoplastic elastomers (TPEs) with the advantage of a good and adjustable balance between elasticity and rigidity in the resulting material. 32 Though, the uncrosslinked rubber exhibits a rather low strength and elasticity.…”

Preparation of a novel styrene copolymer: Simultaneously improving the thermal stability and toughness

“…The modification of PS with SBS can improve the impact resistance, however, the introduction of double bond structure makes the composite more aging and stress cracking. Furthermore, the introduction of highly flammable modifier may further increase the difficulty of halogen‐free flame retardant, which makes the contradiction between flame retardant and toughening . These disadvantages greatly limit the application range of PS.…”

“…In view of the additive flame retardant can damage the mechanical properties of the polymer, one of the most used methods for improving the flame retardancy of PS is reactive method, That is, flame retardant moiety is introduced into PS backbone via radical emulsion copolymerization . It is believed that this method just needs lower loading than the “additive” approach .…”

Synergistic effect of amino silane functional montmorillonite on intumescent flame‐retarded SEBS and its mechanism

“…However, high loadings (>30 wt %) of the flame retardants are needed to impair the flammability of the matrix to a sufficient level which may deleteriously affect the elastic properties of matrix itself. Chemical incorporation of phosphorus containing substituents into poly (styrene‐ block ‐butadiene‐ block ‐styrene) backbone has been reported to improve the substantial fire retardation, while the approach is assessed to be expensive.…”