Adding Flame Retardants Research Articles

The Research on Flame Retardant Wind Turbines Nacelle Made through VARTM Process

During the process of Vacuum Assisted Resin Transfer Molding（VARTM）making flame retardant wind turbines nacelle, the viscosity of unsaturated polyester resin（UPR）with reactive flame retardant groups is too large to be used in VARTM process. In this paper, a large amount of tests were conducted by the way of adding flame retardant of Dimethyl methyl phosphate(DMMP) so as to make the resin fit for VARTM processing properties requirements as well as increase its flame retardant properties to a higher level. The results showed that, when the content of DMMP was 12%, the resin could be provided with lower viscosity with a reduction of 50.3%, making it possible for the resin to be used in vacuum import process. When the content of DMMP reached 12%, LOI of the casting body reached 31.6, with LOI of glass fiber reinforced plastic of 37.0%, the vertical burning classification of which reached V-0 level without significant drop on mechanical properties of fiberglass reinforced plastics(GFRP). Meet the requirements and provide a good material for flame-retardant wind turbines nacelle.

Mechanical properties and flammability of sisal/PP composites: Effect of flame retardant type and content

In this research, magnesium hydroxide (Mg(OH) 2) and zinc borate, as flame retardants, were incorporated into sisal/PP composites. Maleic anhydride grafted polypropylene was also used as a compatibilizer. Adding flame retardants into sisal/PP composites reduced burning rate and increased thermal stability of the composites. No synergistic effect was observed when both magnesium hydroxide and zinc borate were incorporated in the sisal/PP composites. In addition, the sisal/PP composites exhibited insignificant difference of shear viscosity at high shear rate indicating that types of flame retardants used in this study had no impact on the processability of the composites. Good distribution of flame retardants and sisal fiber in PP matrix was also observed. All PP composites had lower impact strength than the neat PP. However, the sisal/PP composites with the addition of Mg(OH) 2 and zinc borate exhibited comparable tensile and flexural properties to the sisal/PP composites without adding those flame retardants. Therefore, the addition of Mg(OH) 2 and zinc borate enhanced flame retardancy of sisal/PP composites without sacrificing their mechanical properties.

Characteristics of lithium-ion battery with non-flammable electrolyte

To improve the safety of lithium-ion batteries, we studied non-flammable electrolytes made by adding several types of phosphazene-based flame retardants to conventional electrolytes and evaluated their conductivities, electrochemical characteristics, and the effects of flame retardants in terms of safety. Cell performance tests and abuse tests were also conducted using cylindrical test cells. The conductivity of electrolytes decreased when phosphazene-based flame retardants were added to the conventional electrolytes. The reason for this decrease in conductivity may be the increase in electrolyte viscosity caused by adding flame retardants. The conductivity decrease led to a decrease in cell capacity at high current density and at low temperature. However, the cell capacities at 0.2 CA (CA = 750 mA) and at 25 °C were almost the same as those of cells using conventional electrolytes. Flame tests showed that the electrolytes with flame retardants exhibited flame resistance consistent with UL-94V0. We also carried out several abuse tests to check the safety improvements. Both overcharge tests up to 10 V and heating tests up to 200 °C were completed without any extraordinary heat generation. Heating tests using a burner revealed the self-extinguishing properties of these electrolytes which were gushed out by venting. These results indicate that electrolytes with phosphazene-based flame retardants are effective for making lithium-ion batteries safe.

Investigation of the properties of asphalt and its mixtures containing flame retardant modifier

The flame retardancy of asphalt binder was improved by adding flame retardants in previous research. The research was conducted to assess the performance of two kinds of flame resistant asphalt mixture compared with the control mixture in laboratory. Differential scanning calorimetry (DSC) and thermogravimetry (TG) were employed to investigate the effect of aluminium hydroxide (ATH) on the thermal properties of asphalt binder. The mixture was designed using Superpave (Superior Performing Pavement) methods and related pavement performance was evaluated. The wheel-tracking was employed to research the dynamic plastic deformation performance. Experimental results illustrated that two kinds of flame resistant asphalt binders have better flame retardancy and all the pavement performances of two kinds of modified asphalt mixture can meet the Superpave design requirements. Therefore, it was feasible to prepare asphalt mixture with the excellent flame retardancy and pavement performance using ATH modified asphalt binders.