Study On One-step Preparation Of Magnesium Hydroxide With Micro/Nano Structures

With the development of industrialization, more and more flammable polymermaterials are used in various fields of our life. The increase of fire accident has madepeople draw more attention in the improvement of flame retardant property of polymermaterials. However the traditional halogen flame retardant would decompose withharmful gas which could be a threat to people’s life and increase the burden on theenvironment. As a halogen-free and non-smoking flame retardant for polymermaterials, magnesium hydroxide has drawn great attention recently. It provides variousgreat advantages, e.g. smoke suppression and neutralization with acid gas frompolymer combustion, and etc. However, due to its low flame-retardant efficiency, highloading is essentially required and commonly results in a negative effect on themechanical properties of the polymer matrix. Furthermore, MH tends to congregate inthe polymer matrix because of its strong polarity. Such a phenomenon could greatlydeteriorate the mechanical properties of a flame-retardant polymeric material.Previously, several methods such as hydrothermal, sol-gel, and precipitationapproaches have been applied to synthesize MH with less polarity and gooddispersibility. However, most of these processes require complicated reactionconditions and long synthesis time which restrict the application extending of MH.Due to the problems of existed synthesis method, we are aiming to obtainwell-dispersed MH in a facile way. In this work, oil phase was used as the reactionmedium with the application of ultrasonic treatment. The product was characterized interms of X-ray Diffraction, Field Emission Scanning Electron Microscope, InfraredTransmission Spectrum, Thermogravimetric Analysis and Differential ScanningCalorimeter. It is concluded that the obtained MH has a spherical shape with aflower-like surface morphology and less polarity with better dipersibility in organicphase. It is also founded that the ultrasonic treatment could decrease the polarity andthe grain size of the product. The oil phase is favorable for synthesizing product withmore uniform morphology and better dispersibility. Besides, the concentration ofreactants, the stirring speed and the reaction temperature are also discussed in thispaper. It reveals that an increase of the concentration of reactants and a reduction of reaction temperature would decrease the polarity and improve the diperisibility of theproduct. Moderate stirring speed would lead to more uniform morphology and bettercompatibility.In conclusion, this work not only brings some useful information for synthesizingMH with low polarity and better dispersibility conveniently which will promote itsapplication into car and electronics industry, but also gives some suggestions for theselecting suitable reaction conditions.