Preparation of urea formaldehyde microsphere and its effect on flame retardant ethylene vinyl acetate composites

Abstract

Urea formaldehyde microsphere (UFM) was prepared and used with organic montmorillonite (OMMT) to modify the flame retardant efficiency of ethylene vinyl acetate copolymer (EVA)/intumescent flame retardant (IFR) composites. The results show that single IFR may modify the flame retardancy of EVA, but its efficiency is not good enough. The EVA composite containing 21 wt% IFR is just classified the UL_94 V2 and has a limiting oxygen index (LOI) 24.7 vol%. Combining UFM with IFR does not improve the flame retardancy of EVA/IFR composites, and blending OMMT with IFR only improves its LOI. Adding 2 wt% UFM, 2 wt% OMMT, and 17 wt% IFR into EVA, it obtains the UL_94 V0 without melt dripping and a LOI 29.0 vol%. Also, the peak heat release rate and total heat release decrease a lot. Good synergistic effects among IFR, UFM, and OMMT improve the char residues and modify the char micromorphology of EVA composites, which provide better protect for the underlying resin.

Recent Advances in Halogen-Free Flame Retardants for Polyolefin Cable Sheath Materials

“…Recently, silica-based FRs have attracted extensive attention in the research on cooperative flame-retardant PO/IFR composites, such as SiO 2 [ 174 , 175 ], MMT (OMMT) [ 176 , 177 ], and polysiloxane [ 147 , 178 ] .…”

“…Meanwhile, POE-MA and nano-CB, as a toughening agent and rigid nanoparticles, respectively, showed significant improvement in elongation at break and tensile strength, reaching 215% and 32.8 MPa, respectively. •Silica-based adjuvants Recently, silica-based FRs have attracted extensive attention in the research on cooperative flame-retardant PO/IFR composites, such as SiO2 [174,175], MMT (OMMT) [176,177],…”

“…The presence of HNTs-Si made the UL-94 test achieve the V-0 level without ignition, and the LOI was further increased to 30.6% from 29.1%. As shown in Figure 15, the cooperative effect of HNTs-Si and IFR promotes the formation of dense and crosslinking carbon layers, which can cover the PP matrix to effectively prevent the release of flammable gases and enhance the flame •Silica-based adjuvants Recently, silica-based FRs have attracted extensive attention in the research on cooperative flame-retardant PO/IFR composites, such as SiO 2 [174,175], MMT (OMMT) [176,177], and polysiloxane [147,178] https://www.x-mol.com/paperRedirect/1296136865981276160.…”

Effect of amino acid‐triazine copolymer on intumescent flame retardant ethylene‐vinyl acetate

“…The application of intumescent flame retardants in EVA has been reported in many literatures, 7,8,28,32,[35][36][37] the related performances are listed in Table 5. The research focuses on the design of new charring agents and synergistic flame retardancy.…”

“…Adding flame retardants into EVA is a common method to improve the flame retardancy of EVA. 7,8 In recent years, a variety of flame retardants have been used in EVA resin, such as halogen flame retardant, metal hydroxides, intumescent flame retardant (IFR) and so on. 8,9 Each flame retardant has advantages and disadvantages, so it is suitable for different fields.…”