Manufacturing of nano-enhanced shape stabilized phase change materials with montmorillonite by Banbury oval rotor mixer for buildings applications

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-PCMs) have attracted attention to address one of the key barriers of phase change materials (PCMs), the leakage during the liquid state, that nowadays limits its applicability. However, SS-PCMs still have drawbacks to overcome, such as poor fire reaction and thermal stability. In the present study, polymeric SS-PCMs 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 a 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, which 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%). The composite materials obtained were not degraded by processing as FT-IR results show. 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.