The Preparation, Structure And Properties Of EVA/LDHs Packaging Nano-Composites With Fire Retardant

The demand of polymer materials is increasing with the developmentof society. Although the application of these materials brings us greatconvenience, it also causes fires easily with a heat source and flame, whichwill bring great loss to people’s lives and properties. Thus it is significant toimprove the flame-retardant performance of polymer with the assurance ofthe comprehensive performance of material mechanics.This project studied on the preparation, structure and performance oflayered double hydroxides(LDHs)/EVA nanocomposite.The main contentsinclude: using chemical precipitation and self-made reactor prapred LDHscontaining multivariant multiple elements which will then be characterized;using melt bleding prapred different types of LDHs/EVA nanocomposites;Through the characterization of different number of elements contained inthe LDHs/EVA nanocomposites, it analysesed the elements’ influence onthe flame-retardant performance of LDHs/EVA nanocomposites; Throughthe analyses of LDHs raw material proportion, the best four-elementingredients of LDHs which are suitable for flame retardant EVA werepinned down, and four-element LDHs/EVA nanocomposite were prepared;through the analyses of interface structure of the nanocomposite, the bestmodifier for LDHs/EVA nanocomposite was established by modifingdifferent modifier and producing composite materials with EVA; Flameretardant composites with great comprehensive properties were producedby the combination of LDHs, Ammonium Polyphosphate (APP) andexpanded graphite; the mechanism of flame retardant LDHs/EVAnanocomposite were discussed by the test results of multivariant andmultiple elements LDHs/EVA nano composites according to the TGanalysis of four-element LDHs together with its burning in differenttemperature, and the composite materials made by burning product andEVA.The results show that: when the particle size of the lamellar LDHs,produced by using the self-made reactor and coprecipitation, is between50~150nm, it possesses good modification effect; the flame-retardantperformance of the nanocomposite were affected by the number of the element of LDHs to a certain extent and improved with more elements, theflame retardant performance of four-element LDHs/EVA improvedtremendously compared to pure EVA. The properties of the compositesimproved with the compatibility and interface property of EVA with LDHswhich were modified by PEG and coupling agent, PEG-2000improved theproperties of composites most. Fe3+affects the water content betweenlayers of LDHs and the flame retardant property in turn, which can be seenfrom the comparison of different LDHs/EVA composite materials; and thenby the analysis of burning product, it found that the flame-retardantproperty of the composites were also affected by water between layers,hydroxyl on the layers and the layered structure affected in some degree.The nanocomposite that could reach to FV-0level were prepared withexpanded granite, APP synergizing LDHs.