Study On Preparation Of MMT/LDH Nanometer Composite And Its Application In Flame Retardant Of Polypropylene

Polypropylene as a general purpose plastic is widely used, polypropylene is burning, however, which makes it has a high risk. Layered double hydroxides(LDHs) is an anionic layered nanometer material and montmorillonite as a ca tionic layered nanometer material, can be used to improve the thermal stability and flame retardant properties of polymer. The controllable structure of layered double hydroxide is the rationale of preparing a LDH with the specific structure. The LDHs, wit h fluorescence properties, can be used in polypropylene and used as identification to study the aging process of polypropylene. Therefore, in order to improve the flame retardant properties and the fluorescence properties of polypropylene, it has important practical significance to design and preparation a kind of layered nanometer material with excellent fluorescence properties and excellent flame retardant properties.In this paper, LDHs with different metal elements were prepared by coprecipitation, LDHs/SDS were prepared by insitu intercalated method, ultrasonic processor was used to prepare a new phase layered nano material, PP/LDH-X 、 PP/MMT-X 、PP/MMT-LDH- X 、 PP/MMT/LDH-X 、 PP/LDH/IFR- X 、 PP/MMT/IFR-X 、PP/MMT-LDH/IFR-X、PP/MMT/LDH/IFR-X were prepared by melt blending method. The X-ray diffraction(XRD), scanning electron micrograph(SEM), fluorescence spectroscopy(PL-PLE), thermogravimetric- infrared spectrometry(TG-IR) analysis means were used to research the impact of sodium dedecyl sulfate to the fluorescence performance of Mg-Al LDH and Mg-Al-Eu LDH, the impact of ultrasonic time on MMT/Mg-Al-Eu LDH composite, the impact of layered nanometer materials on the fluorescence properties and flame retardant properties of polypropylene. The results showed that:(1) Under excitation at 358 nm Mg-Al LDH and Mg-Al-Eu LDH have an emission spectra in the range of 425nm~575nm, sodium dodecyl sulfate can improve the luminous intensity of Mg-Al LDH and Mg-Al-Eu LDH. Under excitation at 358 nm MMT/Mg-Al-Eu LDH have an emission spectra in the range of 425nm~575nm and the intensity of the emission peak increase with the increase of tultrasonic time.(2) Layered nanometer materials evenly dispesed in PP matrix, but there is still a reunion phenomenon. PP/MMT/LDH-4 shows the best thermal stability. The temperature of the maximum weight loss rate of PP/MMT/LDH-4 is 485℃, which is 50℃ higher than PP. PP/MMT-LDH/IFR-4 and PP/MMT/LDH/IFR-4 also present a good thermal stability.(3) With the addition of Mg-Al- Eu LDH increase,the fluorescence performance of PP/LDH-X gradually increase, the fluorescence performance of PP/LDH/ IFR-X increase at first and then decrease. The fluorescence performance of PP/LDH/IFR-4 is the best. With the addition of MMT/Mg-Al- Eu LDH increase, the fluorescence performance of PP/MMT/LDH-X and PP/MMT/LDH/IFR-X increase at first and then decrease.(4) Layered nanometer materials can effectively delay release of combustible gas in the pyrolysis process of polypropylene. The beginning time of combustible gas release from PP/LDH-4 is 33.1 min later than PP and the beginning time of combustible gas release from PP/MMT/LDH/IFR-4 is 7.6 min later than PP/IFR. Layered nanometer materials can improve the flame retardant property.