Properties of nanocomposites substantially improved:

1. Romanian Academy of Science Institute of Physical Chemistry “Ilie Murgulescu” Spl. Independentei 202, 060021 Bucharest, A Nano- Composite Polyethylene glycol-epoxy as Building Element M.Constantinescu1,E.M.Anghel1, M.Olteanu1, A.Stoica1, L.Dumitrache2, M.Ladaniuc2,D.Constantinescu3, C.Perianu Marin3 1 Institute of Physical Chemistry of Rumanian Academy“Ilie Murgulescu” , Bucharest , 2ICECHIM Bucharest, 3 INCERCBucharest . mariella_const@yahoo.com Objectives and importance of this research Material characterization and testing Nano composites preparation Heat storage hanging materials for heating and cooling of buildings, reducing the conventional energy consumption with a direct impact on CO2 emissions, becomes an attractive alternative. The goal of this study was to find the physico-chemical fundamentals of realization of nanocomposites PEG-epoxy as building materials with different geometries and destinations. Unpolarized Raman spectra of the PEG1500-epoxy 30% epoxy resin Ropoxid 501 +70% PEG 1500 +Al powdermelted and mixed with TETA or I 3361hardener + PEG + The advantages of phase change materials: A constant temperature domain for the phase transformation, chosen for each application. High storage density 70-100 kWh/m3 c) Lorenzian deconvolution of the spectrum within 1400-3100 cm-1 (b) Lorenzian deconvoluted Raman spectrum within 160-1400 cm-1 (a) rawspectrum hardener An epoxy- polyethylene glycol 1500 was obtained and characterized : This nano composite material obtained as cross-linked three dimensional structure is attractive for heating and cooling of buildings, reducing space and costs for containerization. Presents good mechanical stability, is homogeneous as can be seen from the SEM measurements Results of the fitting procdure, assignments and literature data of the PEG 1500-epoxy (488 nm laser, room temperature) • Properties of nanocomposites substantially improved: • Mechanical properties : Strength modulus and dimensional stability • Thermal stability , flame retardancy and reduced smoke emissions : • Decreased permeability to gases, water and hydrocarbons PEG Thermo-physical properties of PEG-epoxi nanocomposite Hardening reaction of epoxi resin with PCM Tridimensional epoxi with PCM epoxy Kinetics of hardening reaction for the studied systems in isotherm regime from DSC experiments. PEG1500 where: * Tf is the phase change temperature, specific heat “a” was calculated from thermal conductivity; thermal diffusivity and density were measured in standard conditions. The maximum error for dimensional variation was ± 1.5% even after PEG was melted. DSC for PEG 1500-epoxy+Al Maximum PCM in an epoxi matrix Ropoxid 501+I 3361 , 0 PCM - Ropoxid 501+I 3361 PCM had no influence on the kinetics of the hardening process Green data are for PEG CONCLUSIONS 1. The nanocomposite material to be used as building element was obtained by using melted (PEG1500 +0.1 wt%Al powder,addedfor enhancing the thermal conductivity of the material) 70 wt% incorporated in an epoxidic resin 30 wt%. The Epoxidic resin used was Ropoxid 501 (Policolor), with a hardener threeethylentetramine (TETA) or I 3361 (Policolor). The system hardened at the ambient temperature in 24h and the total reaction was ended after 7 days. 2. From Raman spectra and from the kinetics of hardening reaction can be concluded that epoxy resin is completed cured( Raman bands of the PEG 1500 ; 1275 and 1437 cm-1 are very closed to the epoxide modes :1264 and 1442 cm-1 and the epoxide CH2 stretch at about 3012 cm-1 is absent ) 3. Epoxy resin induces a 10-20 cm-1 deviation toward lower wavenumber of the Raman modes of the polyoxyethylenoglycols 1500 matrix,indicating some interactions at nanoscale. 4. The material presents good mechanical, thermal and chemical properties suitable for building materials. 5. It can be used in different geometries, in active or pasive systems, depending on the chosen application. 6. Energy storage in building materials will reducethe conventional energy consumptions, will increase the living comfort, decreasing the CO2emissions. Thermal conductivity in stationary regime SEM micrographs for polyethylene glycol (PEG) 1500-epoxy