In this study, the graphite effect on the mechanical and fire-retardant performance of low-density polyethylene (LDPE) and ethylene-vinyl-acetate (EVA) foam composites was investigated. Polymer composites were prepared by melt mixing process and foamed by hot press molding at different graphite content (0, 3, 6, and 12 phr). Cone calorimetric tests through heat release rate (HRR) curves obtained, revealed a decreasing of 45% on peak heat release rate (pHRR) of foam composites LDPE-EVA with 12 phr of untreated graphite content compared than those LDPE-EVA foamed composites without graphite, which was attributed to the good distribution of graphite in the composite and more residual generates as thermogravimetric analysis suggested. Mechanical properties of polymer foamed composites with high graphite content do not show significant detrimental as a result to the formation of more uniform cells with smaller size incorporating a material with high modulus like graphite. The results suggest that polymer foam composites with graphite are suitable for the building and construction industry, in sealing and thermal insulation applications with good fire-retardant performance. 相似文献
To improve the flame retardancy of low-density polyethylene (LDPE) and mechanical properties of LDPE composites, phenol-formaldehyde aluminum diethylphosphinate microcapsules (PF@ADP) was prepared by in-situ polymerization with phenol-formaldehyde (PF) resin as the wall material and halogen-free flame-retardant aluminum diethylphosphinate (ADP) as the core material. The effects of PF@ADP on flame retardancy and mechanical properties of LDPE were investigated by methods of combustion experiments, mechanical analysis, thermogravimetric analysis (TGA), and smoke density analysis. The results indicated that, compared with ADP/LDPE composites, the flame retardancy and mechanical properties of PF@ADP/LDPE were obviously improved. With the addition of 20 wt% PF@ADP (PF:ADP = 3:7), the limit oxygen index (LOI) of LDPE composites increased to 30.7% and UL-94 reached V-1 grade. The tensile strength and elongation at break reached 12.5 MPa and 431.2%, which was 20.2% and 23.1% higher than that of ADP/LDPE with the same addition. The addition of PF@ADP was beneficial to the smoke suppression of LDPE. 相似文献
Summary: In the previous study, we observed compatibilizing effects of low density polyethylene (LDPE)/polystyrene (PS) with polystyrene‐block‐poly(ethylene‐co‐butylene)‐block‐polystyrene (SEBS), a triblock copolymer. Blends consisting of 70 wt.‐% LDPE and 30 wt.‐% PS were prepared with a SEBS concentration of up to 10 wt.‐%. This study examined the electrical properties such as the electrical breakdown, water tree length, permittivity and tan δ in the blends. The possibility of using these blends as insulating material substitutes for LDPE was investigated. The electrical breakdown strength reached a maximum of 66.67 kV/mm, which is superior to 50.27 kV/mm of the LDPE used as electrical insulators for cables. In addition, the water tree length decreased with increasing SEBS concentration. The water tree lengths of the blends containing SEBS were shorter than that of the LDPE. The permittivity of the blends was 2.28–2.48 F/m, and decreased with increasing SEBS concentration with the exception of S‐0. Tan δ of the blends increased smoothly with increasing SEBS content.
Breakdown strength , water tree length, permittivity and tan δ of the LDPE/PS/SEBS blends and raw materials. 相似文献
The effect of waste office white paper (WOWP) loading and size on mechanical properties, morphology and thermal properties of LDPE/WOWP composites were investigated. The results showed that increasing of WOWP loading has increased tensile strength and Young's modulus but decreased elongation at break of composites. LDPE/WOWP composites with smaller particle size (31 μm) have higher mechanical properties. Thermal analysis results of composites with particle size (31 μm) show higher thermal stability and crystallinity than composites with particle size (77 μm). Scanning electron microscope (SEM) micrograph indicates that the smaller particle size of filler has better interaction with LDPE matrix. 相似文献