Organic Coatings with Low IR Emission

Cristiana Epure,Alexandru Marin,Viorel Tiganescu,Mihail Munteanu,Teodora Zecheru,Ovidiu Iorga,Andrei Schiopu,Gabriel Epure,Raluca Ginghina,Daniel Turcanu,Cornel Todirica

doi:10.37358/mp.21.3.5502

Abstract

A series of methods were employed to assess the performances of advanced coating materials based on components that can modify the spectral parameters of the surfaces on which these materials are applied in order to obtain passive military camouflage. Powder materials with high infrared (IR) reflectance were used to obtain this type of coatings, which also ingrain in their structure a significant volume of air that allow limitation of the radiative heat transfer of the coated source. The components were embedded in a polyurethane matrix, which facilitated the coating process on different surfaces. The bicomponent polyurethane-based binder used within the different composition tested is transparent to incident IR radiation, has no organic solvents, is highly flexible and possesses remarkable physical, chemical and mechanical properties: high surface adhesion, high flexibility and resistance against a number of chemical agents and external factors with destructive effect. The efficiency of these composite materials was further demonstrated by analyzing the thermal images of different objects.

Highlights

Polymer coatings characterized by complete or selective infrared (IR) reflectivity are employed in many research and industrial fields
The silica was introduced in the powder material to form silica-based aerogels in order to reduce considerably the material surface emissivity due to its over 90% reflectance versus the surrounding environment [918]
Glass microspheres were employed due to their similarity with silica-aerogels, as they embed in their structure a relatively big volume of air, and due to their low expansion thermal coefficient that prevents the formation of cracks and a greater wettability potential [19,20,21,22,23,24,25]

Summary

Introduction

Polymer coatings characterized by complete or selective infrared (IR) reflectivity are employed in many research and industrial fields. E.g., paint or other architectural coatings are used to reflect the incident solar radiation or the heat radiation from inside, obtaining thermal isolations that reduce energetic cost. Military vehicles which are in operation can generate IR radiation from sources such as engines and exhaust plumes. The IR sensors of the thermal camera are capable of detecting the radiation with the wavelength between 7001350 nm (near IR - NIR), 3-5 μm and 8-14 μm (thermal IR - TIR). Thermal imaging cameras measure the relative temperature between the source of radiation and the surrounding environment, identifying the object by its heat or IR signature (the object emitting the radiation has a different color versus the surrounding environment)

Methods

Results

Conclusion