Hybrid silicas/waterborne polyurethane composite properties: In situ formation vs. grafting methods

Heck, Cesar A.; Santos, João Henrique Zimnoch dos; Wolf, Carlos Rodolfo

doi:10.1007/s10971-016-4220-z

Cited by 6 publications

(1 citation statement)

References 34 publications

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“…As sometimes pointed out when building a smart coating, integration of the reservoirs, whatever their type, within the host matrix can be a tricky point. In the case of (nano)silica, particles surface has silanol groups that can react with the isocyanate and locally hinder the polymer chain mobility . To increase the matrix/NCs compatibility and enable dispersion and cohesive interfaces, surface modification is usually achieved and have to take into account the nature of both the containers and the host matrix.…”

Section: Resultsmentioning

confidence: 99%

Incorporation of silica nanocontainers and its impact on a waterborne polyurethane coating

Loison

Denis²,

Groult

et al. 2019

Materials & Corrosion

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In the present work, we describe the development and characterization of a versatile smart coating containing an encapsulated inhibitor. This includes the synthesis and characterization of hollow spherical nanocapsules with diameters ranging from 180 to 200 nm. These particles are able to release their payload when exposed to an alkaline environment, what could be induced by corrosionlinked processes. A corrosion inhibitor, namely 2-mercaptobenzothiazole has been encapsulated, after what the capsules were incorporated in a polyurethane (PU) matrix; optimization of the process led to homogeneous coatings with a good dispersion of silica assessed by micro-fluorescence spectroscopy. Electrochemical impedance spectroscopy highlighted a negative effect of the capsules' addition to the PU network, affecting the coating's barrier properties. However, the release of the inhibitor upon water ingress in the coating and potential short-term protection was seen. Nevertheless, tests conducted on coatings with artificial defects could not lead to a reduction of the corrosion rate, probably due to the large size of the defects. K E Y W O R D Scorrosion protection, electrochemical impedance spectroscopy, silica incorporation, smart coatings

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Section: Resultsmentioning

confidence: 99%