Preparation And Properties Of Nano-carbon/polyurethane Composites

Polyurethane,a polymer of carbamate groups in the backbone,has widely used in foams,plastics,rubber industries and etc.Novel nano-carbon materials(graphene,carbon nanotubes and expanded graphite),have equipped such advantages as follows:low density,high strength,excellent conductive properties and great hydrophobicity.By adding nano-carbon materials into PU,the hydrophobicity and heat resistance and be greatly improved.In this work,we developed a series of composites by compounding PU and nano-carbon materials in different methods.The related properties were also investigated.1.The compound foams were fabricated via one-step method.The nano-carbon materials mentioned above were blended with isocyanate to prepare a composite material.The structure and properties were investigated.The results conducted by SEM indicate that nano-carbon materials were successfully loaded on the surface of foams.The contact angle tests show that nano-carbon materials can greatly improve hydrophobicity.The absorption magnification of polyurethane foam for diesel,gasoline,carbon tetrachloride and cyclohexane is 23,26.78,41.47 and 27.32,respectively.By adding graphene into PU,the corresponding absorption magnification of composite foams can achieve 26.9,36.1,52.8 and 30.2 while the data of carbon nanotubes are 28.6,34,53.2 and 35.8.Both modification methods confirm the possibility of enhancing hydrophobicity and absorption capacity.2.PU foams fabricated by one-step method were further soaked in cyclohexane solution containing nano-carbon materials.The structure and properties of such foams fabricated by two-step method were investigated.The results conducted by SEM indicate that nano-carbon materials were successfully loaded on the surface of foams.The agglomeration of nano-carbon materials can be improved by blending two kinds of soaked nano-carbon materials.The contact angle tests further show that soaked nano-carbon materials can improved the hydrophobicity of materials3.Composite PU foams were fabricated from polyurethane prepolymer and nano-carbon materials.Polyurethane prepolymer was firstly synthesized by the reaction between isocyanate and polyol.The resultants were then blended with nano-carbon materials and were made into films.The structure and properties of such foams were investigated.According to the results conducted by SEM,nano-carbon materials were successfully loaded on the surface of foams and no agglomeration was observed.The results conducted by TGA and contact angle tests show that the heat resistance and hydrophobicity were enhanced as the amount of carbon materials increased.And the mechanical test of films confirms the possibility of improving mechanical properties by adding carbon materials.