IMPROVING THE FLAME RETARDANCY USING NANOPARTICLES IN CABLE INSULATION
Özet
Al(OH)3 (ATH) and Mg(OH)2 (MDH) like materials are frequently used as flame
retardants due to their ability to form water and oxide-based substances under the
influence of heat. In this study, it is aimed to produce cable insulations with improved
flame retardant properties by synthesizing nano-sized Mg(OH)2 and using this material
together with EVA (ethylene-vinyl-acetate) copolymer and micro-sized Al(OH)3 and
Mg(OH)2 .
The study can be divided into four parts. In the first part, the flame retardant
properties of ATH and MDH were compared. In the second part, different raw materials
were used for the synthesis of Mg(OH)2 nanoparticles; in the third part, the synthesis was
carried out at factory scale and compared with the commercial product. The samples were
characterized by scanning electron microscopy (SEM), Fourier transform infrared
spectrometer (FT-IR), X-Ray diffraction analysis (XRD), X-Ray fluorescence analysis
(XRF) and Thermogravimetric analysis (TGA). In the last part, different amounts of
nano-sized Mg(OH)2 particles were added to the formulas using both ATH and MDH;
the effects on flame retardant performances were investigated by the Limiting Oxygen
Index (LOI) test and the vertical burning test. Mechanical properties such as elongation
and tensile strength were also studied.
It has been observed that the synthesized Mg(OH)2 particles with a thickness of 5-
10 nm and lengths reaching 900 nm, mixed in ATH based samples at a maximum rate of
9% and in MDH based samples at a maximum rate of 10%; LOI values increased by 26%
for ATH based samples and 38% for MDH based samples. However, considering the
losses in mechanical properties with the increase of nanoparticle additive, it has been seen
that a maximum rate of 5% nano-sized Mg(OH)2 can be added. Even in this case, the LOI
values increased by 8.6% in ATH based samples and 26% in MDH based samples.
