Flame‐retardant and mechanical properties of high‐density rigid polyurethane foams filled with decabrominated dipheny ethane and expandable graphite

Abstract

ABSTRACT:The article reported the flame-retardant and the mechanical properties of expandable graphite (EG), an intumescent type, and decabrominated dipheny ethane (DBDPE), a gas-phase type of flame-retardant-containing high-density rigid polyurethane foams (RPUF) with a constant density of 0.5g/cm 3 . The results indicated that both EG and DBDPE could effectively interdict the burning of RPUF, besides, the EG exhibited more effective flame retardancy than the DBDPE. When the flame-retardant loadings were 20 wt %, the LOI value of DBDPE-filled RPUF increased to 33 vol %, while, surprisingly, the EGfilled RPUF reached 41 vol %. Unfortunately, when they were both simultaneously added into RPUF, there was not any flame-retardant synergistic effect. Although EG had outstanding flame retardancy, the compressive strength and modulus of 20 wt % EG-filled RPUF dropped to only 9.1MPa and 229.7MPa respectively, which were lower than those of DBDPE (12.4 MPa and 246.8 MPa). The phenomena were ascribed to the different flame-retardant mechanisms of EG and DBDPE, which were verified by scanning electronic microscope (SEM) observation of the burned surfaces. Besides, the dynamical mechanical analysis (DMA) demonstrated that the additions of EG and DBDPE made the glass transition temperature shift to the high temperatures, and the EG-filled RPUF had the higher storage modulus.

Intumescence: Tradition versus novelty. A comprehensive review

“…In term of HRR during combustion, PU foam with 5 pphp intumescent additives had the similar flame retardancy to that with 12 pphp TCPP. [315]. However, the mechanical properties of PU foams were impaired with addition of EG.…”

Synergistic effect of expandable graphite and aluminum hypophosphite on flame‐retardant properties of rigid polyurethane foam

“…In recent years, the simplest way to prevent the burning of RPUF is to add flame retardant additives . The commonly used additives are halogen, phosphorus, nitrogen flame retardants, such as decabromodiphenyl ethane (DBDPE), dimethyl methylphosphonate (DMMP), ammonium polyphosphate (APP), and melamine cyanurate . Expandable graphite (EG) is a novel intumescent flame retardant, and it not only endows polymer materials with good flame retardancy but is also low‐cost and environmentally friendly.…”

Synthesis and characterization of chlorine‐containing flame‐retardant polyurethane nanocomposites via in situ polymerization

“…Polyurethanes (PUs) form a very wide family of polymeric materials (paints, adhesives, elastomers, flexible, and rigid foams) and thus play an important and increasing role in our daily life. Like other organic materials, one of the major drawbacks of PU is their flammability 1, 2. Flame‐retardant additives are usually needed, among which halogenated compounds are most widely used.…”

“…Flame‐retardant additives are usually needed, among which halogenated compounds are most widely used. It is reported that brominated additives represent 25–30% of the total flame‐retardant consumption in the United States and the Western Europe 1. From the point view of flame retardancy, the halogenated flame retardants are most effective and cannot be substituted in many applications to date; but, in certain cases, they may give rise to environmental problems 1, 3.…”

“…It is reported that brominated additives represent 25–30% of the total flame‐retardant consumption in the United States and the Western Europe 1. From the point view of flame retardancy, the halogenated flame retardants are most effective and cannot be substituted in many applications to date; but, in certain cases, they may give rise to environmental problems 1, 3. Replacing carbon and hydrogen atoms in the polymer with inorganic atoms such as chlorine,4–6 silicon,7–9 nitrogen,10, 11 sulfur,3 or phosphorus7, 12, 13 results in a polymer with reduced flammability due to increased heat resistance and lower fuel value 11.…”