Enhancement of thermal stability and flame retardancy of ethylene vinyl acetate/magnesium hydroxide composite by carbon black

J of Applied Polymer Sci

et al. 2023

In this article, MHPA, a novel bio-based flame retardant, was prepared by a reaction of magnesium hydroxide (MH) and phytic acid (PA). Then, MHPA was added into high-density polyethylene (HDPE) to prepare flame-retardant HDPE composite. This work aims to add MHPA into HDPE to flame-retardant HDPE composites by melt blending to significantly reduce the smoke and toxic gases produced during combustion. The limiting oxygen index (LOI) and cone calorimeter test (CCT) results show that the flame retardancy and smoke suppression of HDPE can be improved by the mixture of MHPA and MH. The LOI of HDPE/MHPA/MH was 26.3%, and its peak heat release rate (pHRR), total heat release (THR) and total smoke production (TSP) values decreased by 38.6%, 27.3%, and 65.2%, respectively, compared with pure HDPE. In addition, HDPE/ MHPA/MH composites have significant tensile strength, elongation breaking strength, and tear strength because of the interface compatibility of bio-based MHPA. Therefore, this study verified that the flame retardancy, smoke suppression, and mechanical properties of HDPE composites could be effectively improved when MHPA and MH are added to HDPE simultaneously.

Section: Resultsmentioning

confidence: 98%

Development of bio‐based magnesium phosphate flame retardant for simultaneously improved flame retardancy, smoke suppression and mechanical properties of HDPE

Feng

J of Applied Polymer Sci

et al. 2023

“…For example, the limiting oxygen index (LOI) of high density polyethylene filled by 33.3 wt% MH is only 20%. The LOI increases to 25.6% when only a tiny amount of silicon rubber is added. [22] In addition, the introduction of some flame retardant elements onto MH surface through proper surface modification can also increase the flame retardant efficiency of MH observably.…”

Section: Introductionmentioning

confidence: 99%

“…To solve this problem, some synergistic additives are used to improve the flame retardant efficiency of MH. The synergistic agents reported in literature include aluminum trihydrate, [13] SiO 2 , [14] red phosphorus, [15,16] expandable graphite (EG), [17,18] organosilicon, [19] nanoclay, [20,21] silicone rubber, [22] carbon nanomaterials, such as carbon nanotube, [23] graphene, [24] carbon black, [25] carbon microsphere, [26] and so forth. By introducing proper synergists, the flame retardant efficiency of MH is raised and the amount of FR can be reduced to a certain degree.…”

Section: Introductionmentioning

confidence: 99%

Enhanced flame retardancy, smoke suppression, and acid resistance of polypropylene/magnesium hydroxide composite by expandable graphite and microencapsulated red phosphorus

Liang

Vinyl Additive Technology

et al. 2023

Self Cite

Low flame retardant efficiency and poor acid resistance of filled polymer composites are two main drawbacks of magnesium hydroxide (MH) as a flame retardant (FR). To solve these problems, expandable graphite (EG) and microencapsulated red phosphorus (MRP) were introduced into polypropylene/ magnesium hydroxide (PP/MH) composite by melt compounding. The obtained PP/MH/EG/MRP quadruple composite was studied regarding its fire behavior as well as acid resistance. Obvious flame retardant synergism among MH, EG, and MRP is found in PP, which diminishes the loading of FR from 63.0 to 37.5 wt% to obtain V-0 rating in UL-94 test and low smoke release.Compact intumescent char with high thermo-oxidative stability was generated on composite surface, which plays a vital role in flame retardancy. The removal of MH by acid erosion on PP/MH/EG/MRP composite surface does not affect production of intumescent char and fire behavior of this composite.

“…To improve fire safety, many halogen-free flame retardants (HFFRs) are employed to flame-retard EVA. Among these HFFRs, metal hydroxide, such as magnesium hydroxide (MH), aluminum trihydrate (ATH) and layered double hydroxide, [1][2][3][4][5] intumescent flame retardant (IFR), [6][7][8] and nanofillers, [9][10][11] are intensively investigated in literature.…”

Section: Introductionmentioning

confidence: 99%

Concurrently improving fire safety and processability of ethylene vinyl acetate copolymer by expandable graphite and polyphosphoric acid

et al. 2023

Self Cite

Ethylene vinyl acetate copolymer (EVA) was modified by expandable graphite (EG) and polyphosphoric acid (PPA) in melt state and the obtained EVA/EG/PPA composite was studied regarding its fire behavior, thermal endurance, water resistivity, processability, and mechanical property. The outcomes evince that the combination of EG and PPA in proper mass ratio can improve fire retardancy, thermal stability, processability, and reduce smoke and toxic gas releases of EVA upon combustion significantly. The EG/PPA combination exhibits very high flame retardant efficiency to EVA in that only 10 wt% loading is enough to make EVA obtain V‐0 rating in UL‐94 test. Moreover, the flame‐retarded EVA/EG/PPA composite displays excellent water resistance and acceptable mechanical property. The EVA/EG/PPA (90/7.5/2.5) composite can produce coherent intumescent char on composite surface, which has good heat endurance and hinders heat transmission from fire to interior of composite. The flame retardation occurs in condensed phase and the intumescent char plays a pivotal role. The presence of PPA endows EVA composite with good melt flowability, which has presented a striking contrast to other flame retardants.Highlights The combination of EG and PPA has very high flame retardant efficiency to EVA. The EVA/EG/PPA composite has better fire safety and processability than EVA. The EVA/EG/PPA composite still maintains acceptable mechanical property. The expanded char from EVA/EG/PPA composite hinders heat transfer effectively.