The effect of the structure of multifunctional CNT polyurethane coatings on their heat conductivity: Presentation held at Coatings for the Next Decade; 1st European Technical Coatings Congress, 4-6 June 2012, Lausanne, Switzerland. FATIPEC-OCCA Congress

Abstract

Polyurethane water-borne coatings attract considerable attention for their comprehensive fields of perspective applications in construction and automotive industries due to good permanent stability, protection, mechanical properties and high gloss. In several applications it is important, in addition to other required characteristics, to provide high thermal conductivity by coatings in order to decrease heat accumulation and to protect the automotive and construction parts and the coating itself from overheating. To advance further the functional performance and to broaden the fields of application of water-borne polyurethane coatings, multiwall carbon nanotubes (CNT) were incorporated in polyurethane water-borne compositions. CNT containing coatings based on polyurethane water-borne composition and CNT dispersion were prepared and evaluated with regard to their thermal transport, mechanical strength and other characteristics. The effect of the incorporation of CNT, of the composition and structure of the coatings on their multifunctional performance is discussed. The SEM images demonstrate a relatively uniform distribution of CNT in polymer matrix at low CNT content. For the characterisation of the thermal transport in coatings a set-up of devices based on an IR source and an IR detector was used. Thermal transport of CNT containing coatings was evaluated and compared with that of coatings containing carbon black. It was demonstrated that carbon black polyurethane coatings may contain more than 3 times higher amount of filler compared to CNT containing compositions to achieve similar thermal conductivity of coatings. CNT are known for their mechanical strength, electrical conductivity and other advanced properties due to their structure and high surface area. The incorporation of CNT in polyurethane surface coating compositions provided additional benefits to the functional performance of polyurethane coatings while maintaining the advantages of the polymer system, thus creating a basis to manufacture multifunctional environmentally friendly surface coatings