Thermoresponsive Hybrid Colloidal Capsules as an Inorganic Additive for Fire-Resistant Silicone-Based Coatings

Publication Name

Industrial and Engineering Chemistry Research

Abstract

Improving the fire-resistant efficiency of silicone-based polymeric coatings is important in the building industry and electrical utilities. In this study, the water-containing hybrid calcium carbonate (CaCO3)-silica (SiO2) colloidal capsule has been developed and optimized as an inorganic flame-retardant additive. This capsule exhibits excellent thermal stability up to 1000 °C with a remaining intact hollow spherical structure. When used as an inorganic filler at 15 wt %, it not only reduces the potential fire hazards by over 44% (i.e., the sumHRC reduced from 112.00 J/g K to 62.00 J/g K) but also improves the heat-barrier efficiency by over 30% (i.e., the temperature at the steady state reduced from 350 to 360 °C to below 250 °C) of the silicone-based polymeric coatings. In addition, the capsule-polymer composite coating exhibits excellent ductility which can withstand heat-induced mechanical stresses and prevent crack propagation under radiative heating conditions. The fire-resistant mechanism of the colloidal capsule is related strongly to the encapsulated water core and the reactions between SiO2and CaCO3at elevated temperatures. They not only contribute to a cooling effect on the flammable pyrolysis gases but also induce the insulative effect to the resulted char during combustion. The significant advances in this study will have a high impact in customizing the functional inorganic additives for a better design of the flame-retardant composite coating.

Open Access Status

This publication may be available as open access

Volume

61

Issue

35

First Page

13104

Last Page

13116

Funding Number

DP190103455

Funding Sponsor

Australian Research Council

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Link to publisher version (DOI)

http://dx.doi.org/10.1021/acs.iecr.2c01967