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The present study covers the development and testing of polyurethane (PU) foams modified with phase change materials (PCMs) supported in inorganic silica containers. Two kind of inorganic supports (mesoporous silica and tight silica microcapsules) were selected as representative cases of two alternatives for the preparation of phase change composites: infiltration of PCMs on porous supports and microencapsulation of PCMs. The two types of phase change composites exhibit latent heats of 100–130 J·g−1 and PCM uptakes of 45–60%. The addition of the phase change composites to the formulation of a rigid PU foam promoted subtle changes in the foam growth process which were responsible of a cell‐size contraction and of strengthening the compressive strength in a 27–30%. The thermal performance of the PU foams was tested under isothermal laboratory conditions showing higher thermal storage capacity in doped foams. Additionally, the higher energy storage capacity of the modified foams provides them greater thermal inertia. POLYM. COMPOS., 39:1420–1432, 2018. © 2016 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Materials science offers solutions that when are combined can offer important energy savings in the building sector. In this study, high reflectance coating and thermal storage capacity are combined with the aim of improving energy efficiency in buildings. For this issue a multifunctional pigment having a phase change material adsorbed on its surface and a high total solar reflectance has been manufactured. The total solar reflectance of the pigment will make the paint to reflect the sunlight radiation in the infrared part of the spectrum reducing the amount of absorbed radiation. This high reflection provides a surface level effect as is a passive stimulus-responsive solution that acts with sunlight radiation. On the other hand, the thermal storage capability provides a bulk level effect as is passive stimulus-responsive solution acting by temperature changes, making it possible to use constructive materials as a thermal energy storage media. The preparation process is described and the pigment is characterized conveniently. The thermal performance of corresponding pigmented coatings was evaluated by an experiment simulation in which different boxes were covered with the coating containing the multifunctional pigment and traditional pigmented coating on their tops. The indoor air temperature and the interior temperature of the substrate were measured obtaining differences of 4–5°C. [ABSTRACT FROM AUTHOR]

The performance of the vacuum infiltration technique to develop content-stable phase change composites is thoroughly analyzed for a representative spectrum of solid supports that cover a wide range of pore sizes, from micropores (>0.6 nm) to macropores (<200 µm). Particularly, the discussion of the results addresses how the porous features affect the amount of embeddable PCM, the phase change properties and the cycling stability of the composites. In terms of latent heat and cycling stability, conventionally used solid supports, such as bentonite, zeolites, diatomaceous earth and expanded graphite, appear to be less advantageous than mesoporous silica. The content stability provided by the nanosized pores of the composite developed with mesoporous silica reduces the risk of PCM leakage and makes this composite suitable for use in building materials without requiring a protective coating. The characterization of the phase change features is also accomplished by thermodiffractometric measurements on composite samples to analyze their main crystallographic properties. Finally, the effect of nano-confinement within the porous matrix on the phase change properties is discussed by focusing on the shifts observed for supercooling and melting point depression. [ABSTRACT FROM AUTHOR]

The present work is a first approach in order to achieve thermo-sensitive and waterproof polyurethane fibers useful in the textile industry. For this, two polyurethane formulations with glass transition temperatures (T g) close to the body temperature have been synthetized and characterized by several techniques such as Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Dynamic-Mechanical Analysis (DMA) and Thermo-mechanical analysis (TMA). In this manner their thermal and shape memory behavior were determined. It was also estimated the water vapor transmission rate of both polyurethane films. Then, integration of two different microencapsulated phase change materials (PCMs), one with organic shell and another one, with an inorganic shell, was carried out by extrusion in order to achieve materials with thermo-regulating properties. Fibers for both polyurethanes, pristine or loaded with microencapsulated PCMs, were again characterized to check that the thermal and shape memory properties are maintained, and to study their capability to storage and release energy. The promising results pave the way for a new generation of thermo-regulating materials useful in numerous applications such as the textile sector. • Thermo-regulating and waterproof textiles from shape memory polyurethanes (SMPUs). • Shape memory polyurethanes fibers loaded with microencapsulated phase-change materials (MEPCMs). • Phase-change materials (MEPCMs) are capable to store and release energy in a specific temperature range. • New generation of thermo-regulating materials useful in numerous applications such as the textile sector. [ABSTRACT FROM AUTHOR]