The Preparation Of Flame Retardant Oil/Water Separation Foam Based Materials And The Study Of Their Properties

With the development of oil industry,the frequency of oil spill accidents rises.The oil leakage is not only a serious problem for the environment,but also a threat for the human health.In addition,the usage storage tanks in petrochemical industry and thermal power generation frequently causes accidents of leakage,fire and explosion,which may cause serious casualties,environmental damage and economical losses.Either oil spill accidents on the sea or oil tank leakage accidents on land need emergency treatment method to prevent the oil spilled from spreading to a larger area or evaporating which may cause fire or explosion disasters.The using of oil/water separation and oil absorption materials can treat both oil spill accidents on the sea and oil tank leakage accidents,which is a safety technical method for the treatment of oil spill and leakage accidents.However,most oil/separation and oil absorption materials reported now are polymers,most of which have high flammability because of their organic structures,which have fire safety hazards in the storage and transportation.The oil spilled or leaked with the volatilization of flammable gases may cause fire disaster.The high flammability limits the applications of the materials in the accidents treatment.Therefore,for the preparation of effective oil/water and oil absorption materials,the flame retardancy of the product must be taken into consideration.Most foam materials with three-dimensional porous structures have large specific surface area,high porosity,which can be ideal substrates for the preparation of oil/water separation and oil absorption materials.In our work,we use commercial available flexible polyurethane foam and melamine foam as substrates,putting forward an idea that using layer-by-layer assembly technique,we can deposit the flame retardant particles with different surface energy on the surface of the substrates to endow the substrates with good performance in oil/water separation and flame retardancy.To realize the idea,the surface modification,properties in oil/water separation,oil absorption and flame retardancy of flexible polyurethane foam and melamine foam are studied,the content of which can be illustrated in detail as follow:1.Using the flexible polyurethane foam as substrates,Layer-by-layer assembly technique is adopted to deposit the polyethyleneimine?PEI?/ sodium alginate?SA?and cellulose phosphating derivatives?PC?/chitosan?CH?onto the surface of the substrates respectively to endow the foam with hydrophilicity and underwater oleophobicity.The result of contact angle shows that the water contact angle of the modified samples is 0°,which means the superhydrophilicity of the modified foams.The result of oil/water separation test shows both PEI/SA and PC/CH modified foams can effectively separate oil and water mixture,the thermogravimetric analysis shows good thermal stability of PC/CH modified foams in the temperature of 285 °C-700 °C.The cone calorimeter test shows the Peak heat release rate of 15 PC/CH layers modified foams 60.3% lower than that of the pure one and the total heat release 30.3% lower than that of the pure one,which may result from the catalytic carbonization of the phosphorus compounds.2.Layer-by-layer assembly technique is adopted to deposite the Mg?OH?₂ and montmorillonite?MMT?onto the surface of the flexible polyurethane foam respectively to increase the roughness of the surface.After further modification by dodecanethiol which have low surface energy to endow the surface of hydrophobicity and oleophilicity.The water contact angles of Mg?OH?₂ modified and MMT modified come up to 136° and 135° respectively.The absorption rates of different kinds of oil and organic liquid range from 16 to 64 times of their own weight.The rate keeps high after 50 cycles of absorption.The thermogravimetric analysis shows good thermal stability of all modified samples.The cone calorimeter test shows the peak heat release rate of 8 MMT layers modified sample and the sample with most Mg?OH?₂ loading much lower than that of the pure one which result from the flame retardancy of MMT and Mg?OH?₂.3.Firstly,layer-by-layer assembly technique is adopted to deposit MMT onto the surface of the flexible polyurethane foam,then,polydimethylsiloxane is used for further modification to endow the foam with superhydrophobicity and superoleophilicity of which the water contact angle larger than 150°,the as-prepared samples can effectively absorb the oil layer on water.The absorption rates of different kinds o f oil and organic liquid range from 20 to 70 times of their own weights.The thermogravimetric analysis shows the char residue of 6 MMT filled layers modified sample at 700 much lower than that of the pure one and the cone calorimeter test shows the peak heat release rate of 6 MMT filled layers modified sample 80% lower than that of the pure one.4.Using the melamine foam as substrates,Layer-by-layer assembly technique is adopted to deposit the flame retardant two-dimensional particles of MMT and ?-ZrP onto the surface of the substrates respectively to increase the surface roughness of the substrates,then dimethyldichlorosilane and methyl trichlorosilane are used for further modification to endow the foam with superhydrophobicity and superoleophilicity of which the water contact angle larger than 150°.The absorption rates of modified samples of different kinds of oil and organic liquid range from 28 to 131 times of their own weights.thermogravimetric analysis shows better thermal stability of modified foams than that of the pure one in high temperature.The modified foams show more integrated char than that of the pure one after being deposited on the temperature of 500 °C.5.The design and application of the oil/water separation and oil absorption materials prepared in this paper are prospected and discussed.