Preparation and thermal properties of a novel core‐shell structure flame‐retardant copolymer

Abstract

In order to improve the flame retardancy of polystyrene (PS), a phosphorus and nitrogen comonomer, named AC2NP2, was synthesized and then incorporated into various amounts of PS by seeded emulsion polymerization. The modified methacrylate (AC2NP2) was used as the core phase, the styrene as the shell phase, then flame‐retardant effect copolymers with core‐shell structure were prepared successfully. The particle size was ranged from 40 to 60 nm, and the structure and properties of the copolymers were characterized in detail. Notably, despite a few amounts of the AC2NP2 units in the copolymers, all the copolymers exhibited significantly enhanced thermal stability and reduced flammability as compared with pure PS. Furthermore, from differential scanning calorimetry test, it was observed that the glass transition temperature was tinily influenced with the incorporation of commoner. The incorporation of P‐N comonomer into PS backbone did not lead to negative effect on the glass transition behavior of PS.

Reactive and Additive Modifications of Styrenic Polymers with Phosphorus-Containing Compounds and Their Effects on Fire Retardance

“…The chemical incorporation of fire-retarding species into the polymeric chains through covalent bonding is known as a reactive modification. The P-containing monomer(s) with double (-C=C-) bonds can be co- or ter- polymerised with the monomer of styrene (St) to produce the polymeric systems with improved fire retardance [ 48 , 107 , 108 ]. The reactive modification is particularly attractive because the fire-retarding groups, which are linked to the polymeric chains via covalent bonds, tend not to leach out from the polymer during its processing and the consequent use.…”

“…In another study, Cui et al (2017) used the same P–N comonomer, AC 2 NP 2 , in the amounts ranging from 5 to 20 g for the preparation of styrene-based copolymer via the seeded emulsion polymerisation ( Figure 26 ) [ 107 ]. During the emulsion polymerisation, water was used as the emulsion medium along with the emulsifiers, sodium lauryl benzene sulfate and sodium p- styrene sulfonate.…”

“…The fire-retarding mechanism of the AC 2 NP 2 units was determined from various characterisation and flammability studies, clearly highlighting the synergistic P–N effects. The impact of this synergism strengthened as the content of AC 2 NP 2 in the copolymer grew up to 20 g [ 107 ].…”

“…Table 2 summarises the data obtained from various flammability studies of the PS homopolymer and the copolymer of St with 10 wt% of AC 2 NP 2 prepared through the solution and emulsion polymerisation techniques [ 107 , 119 ]. The polymeric samples prepared in the solution or emulsion showed higher char residue (CR) under the air atmosphere than that produced in the inert atmosphere.…”

A facile method for preparation of PGS@ZB‐N and gas‐sol alternating synergistic effect for fire resistance of EVA

“…[17][18][19] For the most important role of the synergistic effects in flame retardant research, many studies have been carried out. To now, most research about synergistic effect were focused on the P-N system [20][21][22][23][24] ; however, there were few attentions paid to the B-N group. 25 In our previous work, we have combined PGS, boric acid (B), and dodecylamine (N) to construct a flame retardant of PGS@B-N to improve the flame retardancy of EVA.…”