Polymer layered silicate nanocomposites for latent heat thermal energy storage

Identifier:  TFM:596

Handle: https://hdl.handle.net/20.500.11797/TFM596

Authors:  Martín Llop, Marc

Abstract:
The use of adequate thermal energy storage (TES) systems has shown the potential to increase energy efficiency in many fields, such as the building sector. Shape-stabilized phase change materials (SS-PCM) have attracted attention to address one of the key barriers of phase change materials (PCM), the liquid management, that nowadays limits its applicability. However, SS-PCM still have drawbacks to overcome, such as poor mechanical properties, fire reaction and thermal stability. In the present study, polymeric SS-PCM are nano-enhanced with layered silicates to overcome these drawbacks. The new shape-stabilized nano-enhanced phase change material (SS-NEPCM) is based on ethylene propylene diene monomer (EPDM) as polymeric matrix, palmitic acid (PA) as PCM and montmorillonite (MMT) as the layered silicate. An innovative method based on a Banbury mixer was used to prepare it, that is an industrially scalable fabrication method. To evaluate the effect of each component, eight different formulations were prepared: pure EPDM, EPDM with MMT additions (1 wt.%, 3 wt.% and 5 wt.%), EPDM with PA additions (5 wt.% and 10 wt.%) and EPDM with MMT (3 wt.%) and PA additions (5 wt.% and 10 wt.%). As it was investigated by Fourier-transform infrared (FT-IR) spectroscopy, the composite materials obtained were not degraded by processing. The results obtained by X-ray diffraction showed that an ordered intercalated morphology is formed between EPDM chains and MMT. Thermogravimetric experimental results revealed an increase in the thermal stability of SS-NEPCM as a result of the barrier effect provided by MMT. Moreover, SS-NEPCM fire resistance was improved with a great reduction or avoidance of the dripping phenomenon. Additionally, dynamic mechanical thermal analyses demonstrated that 3 wt.% MMT is an optimum content to enhance thermomechanical properties in the EPDM rubbery region.