Interfacial modification of high impact polystyrene magnesium hydroxide composites effects on flame retardancy properties

Abstract

High impact polystyrene (HIPS)/magnesium hydroxide (MH) composites were prepared by meltblending. Two kinds of interfacial modifiers were used in this research, maleinated poly[styrene-b-(ethylene-co-butylene)-b-styrene] (SEBS-g-MA) triblock copolymer and PS. The effects of the use levels of SEBS-g-MA on the flame retardancy of HIPS/elastomer/MH based on unmodified and PS-modified surface were investigated by TEM, FTIR, and combustion tests (horizontal burning test and cone calorimetry). The combustion results showed that comparing composites containing unmodified MH, the flame retarding properties of composites containing PS-modified MH were obviously improved. The increased performance can be explained that the PS covered on the surface of MH could further improve dispersion of the filler in matrix. Furthermore, there existed a critical thickness of interfacial boundary for optimum flame-retarding properties in both ternary composites based MH and PS-modified MH. When the interfacial boundary relative thickness is less than 0.53, the introduction of SEBS-g-MA can improve the dispersion degree, leading the improvement of flame retardancy properties. However, with the increase of interfacial boundary thickness, the SEBS-g-MA coating around MH acted as a heat and mass transfer barrier, leading to the reduction of flame retardancy.

Improvement of the Compatibilization of High-Impact Polystyrene/Magnesium Hydroxide Composites with Partially Sulfonated Polystyrene as Macromolecular Compatibilizers

“…Traditional FRs are usually halogen based ones (HBFRs), ,, which have been proven effective in flame retardance. Nevertheless, polymers containing HBFRs will be accompanied by negative effects such as corrosiveness, smoke emission, and toxic combustion products in fire. , With the enhancement of public awareness of environmental protection and under the pressure of new laws and regulations, , there is a growing demand for halogen free FRs (HFFRs) instead of HBFRs, in which magnesium hydroxide (MH) − and alumina trihydrate (ATH) have received considerable attention from both academia and industry. MH, due to its higher decomposition temperature, , can be applied in a wider range than ATH.…”

“…In order to overcome these drawbacks, it is essential to modify the surface of MH particles using surface modifiers, , which include macromolecular compatibilizers and low-molecular-weight ones. ,− Although low-molecular compatibilizers, such as surface active agents, silane coupling agents, , and titanate coupling agents, are inexpensive and have shown availability to some degree, their hydrophobic chains are too short to anchor to the polymer matrix tightly. ,, On the contrary, macromolecular compatibilizers, in comparison with low-molecular ones, are more beneficial to bridging the inorganic and organic phases through physical entanglements and van der Waals interactions in virtue of their longer flexible chains. Hence, in recent years, an increasing number of studies have been focused on macromolecular compatibilizers. ,, …”

“…In the past decades, many kinds of macromolecular compatibilizers ,, based on various functional groups at various hydrophobic chains have been reported to enhance the performance of HIPS based flame retardant composites, for example, styrene-butadiene-styrene block copolymer (SBS), ethylene-propylene-diene monomer rubber (EPDM), ethylene-vinyl acetate copolymer (EVA), poly­[styrene- b -(ethylene- co -butylene)- b -styrene] (SEBS), poly­[styrene- b -(ethylene- co -butylene)- b -styrene]- g -maleic anhydride (SEBS- g -MAH), , etc. All of them have improved the mechanical and/or thermal properties more or less.…”

Effects of magnesium hydroxide and its synergistic systems on the flame retardance of polyformaldehyde

“…Compared with phosphorus‐containing compounds, inorganic flame retardants, such as magnesium hydroxide (MH) possess many advantages including environment‐friendliness, good smoke and melt drip suppression, and a low cost, thus increasingly applied in polymer materials in recent years 8–12. However, few investigations were reported concerning inorganic flame retardant POM system due to its high loading level.…”

Mg(OH)2/polystyrene Hybrid Nanocomposite Particles Prepared by Emulsion Polymerization

“…Mg(OH) 2 has also drawn interest as an environmentally friendly halogen-free additive giving enhanced flame retardancy for ethylene-vinyl acetate copolymers, polypropylene, high impact polystyrene (HIPS) etc. [11][12][13][14] . The rheological and flame retardant properties of HIPS/PS-encapsulated Mg(OH) 2 composites were found to be significantly improved compared to the composites containing untreated Mg(OH) 2 , this being mostly attributed to a better dispersion of the encapsulated filler and a strong adhesion between the filler and matrix 15 .…”