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Investigation into millet for use as an eco-friendly intumescent coating for passive fire protection
Thesis (MEng)--Stellenbosch University, 2024.
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Stellenbosch : Stellenbosch University
2025
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| _version_ | 1867614086472138752 |
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| access_status_str | Open Access |
| author | Vermeulen, Zara Stefanie |
| author2 | Walls, Richard |
| author_browse | Vermeulen, Zara Stefanie Walls, Richard |
| author_facet | Walls, Richard Vermeulen, Zara Stefanie |
| author_sort | Vermeulen, Zara Stefanie |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description |
Thesis (MEng)--Stellenbosch University, 2024. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/131965 |
| institution | Stellenbosch University (South Africa) |
| last_indexed | 2026-06-10T12:46:25.318Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2025 |
| publishDateRange | 2025 |
| publishDateSort | 2025 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/131965 Investigation into millet for use as an eco-friendly intumescent coating for passive fire protection Vermeulen, Zara Stefanie Walls, Richard Flores-Quiroz, Natalia Stellenbosch University. Faculty of Engineering. Dept. of Civil Engineering. Fire resistant materials Paint, Fireproof Millets -- Thermal properties Coatings -- Thermal properties UCTD Thesis (MEng)--Stellenbosch University, 2024. ENGLISH ABSTRACT: lntumescent paints or coatings are a popular form of passive fire protection in the fire industry. They typically form a carbonaceous layer when exposed to heat to provide a thermal barrier to structural elements. However, intumescent paints release considerable toxic products during combustion leading to health and environmental hazards. The impact of their toxicity is an important consideration for sustainability, and whether this can be reduced with the inclusion of greener materials should be studied. Past testing in literature and scoping work has identified that an agricultural crop, known as millet, does intumesce when heated. This work explores the question: can millet be used as a base component for the development of a green passive protection product? This work considers the physical characteristics and thermal resistance development of the grain. The material was analysed using three experimental methods, namely, thermogravimetric analysis, hot stage analysis, and cone calorimetry. Millet underwent thermogravimetric analysis in an inert {nitrogen} and oxidizing {air} environment. This was done to study the influence of oxygen on intumescent behaviour. ln air, the whole and ground millet were found to behave similarly, with material residues of 3 % and 2 %, respectively. The ground millet was additionally compared to previously completed samples of ground millet in nitrogen, with residues of 17 % and 2 %, for nitrogen and air, respectively. Additional thermal degradation occurs in air due to thermal oxidation in an oxidizing environment, leading to material gasification in the presence of oxygen. Hence, reducing the residual weight and providing a lower level of thermal resistance as compared to the nitrogen environment. Hot stage analysis was conducted for whole millet, to provide visual representation of the thermal degradation of a singular grain with identification of the decomposition stages. The decomposition stages included initial and maximum expansion. The analysis furthermore confirmed the release of gases and compounds from the grain during combustion, to highlight the influence of released compounds on the intumescent process, and the potential of these compounds to drive intumescence. The cone calorimeter experiments involved larger scale whole and ground millet samples distributed over a steel substrate to study the extent of thermal resistance and behaviour of the sample as compared to a singular grain. Both whole and ground millet provided improved thermal resistance to the substrate through formation of an expanded lattice-like structure with micro-scale openings. This demonstrated good potential of millet to provide protection to steel members in a fire, and to be used as a form of passive protection. Several preliminary paint mixes were developed with the millet in combination with applicable binders. These mixes underwent preliminary analysis for observation of initial thermal behaviour and intumescent potential. This work highlighted the intricacies of intumescent behaviour when developing a reliable intumescent paint and the high influences of components on intumescence. As a material, millet is shown to be a very promising biomass for the development of green passive protection systems, and has been characterised in detail in this thesis. The primary problem in paint development has been the lack of cohesion and pull-away between the sample and substrate, which requires future research. AFRIKAANSE OPSOMMING: Swellende verf of lae is 'n gewilde vorm van passiewe brandbeskerming in die brand bedryf. Hierdie lae vorm tipies 'n koolstofdraende lag wanneer dit aan hitte blootegestel word, wat 'n termiese versperring vir strukturele elemente bied. Intumescerende verf stel egter beduidende hoeveelhede toksiese produkte vry tydens verbranding, wat lei tot gesondheids- en omgewingsgevare. Die impak van intumescerende verf met betrekking tot hul toksisiteit is 'n belangrike oorweging vir volhoubaarheid, en of hul impak verminder kan word deur die insluiting van groener materiale behoort bestudeer te word. Vorige toetsing in literatuur en verkennende werk het geidentifiseer dat 'n landbougewas, bekend as millet, wel intumesceer wanneer dit verhit word, daarom ondersoek hierdie werk die vraag: kan millet gebruik word as 'n basiskomponent vir die ontwikkeling van 'n groen passiewe beskermingsproduk? Die werk oorweeg die fisiese eienskappe en die ontwikkeling van termiese weerstand van die graan. Die materiaal is geanaliseer met behulp van drie eksperimentele metodes, naamlik, termogravimetriese analise, warmfase analise, en 'cone calorimeter'. Millet het eerstens termogravimetriese analise ondergaan, in 'n trae (stikstof) en oksiderende (lug) atmosfeer. Dit was gedoen om de invloed van suurstof op intumescerende gedrag te bestudeer. Dit is gevind dat heel en gemaalde millet soortgelyk optree in lug, met materiaalresidue van onderskeidelik 2 % en 3 %. Die gemaalde millet was verder vergelyk met vorige monsters van gemaalde millet in stikstof, met residu van onderskeidelik 17 % en 2 % vir stikstof en lug. Addisionele termiese ontbinding vind plaas in lug as gevolg van termiese oksidasie wat in 'n oksiderende omgewing voorkom, wat lei tot materiaalvergassing in die teenwoordigheid van suurstof. Gevolglik verminder dit die oorblywende gewig en bied dit 'n laer vlak van termiese weerstand in vergelyking met die stikstofomgewing. Warmfase analise is uitgevoer vir heel millet, om 'n visuele voorstelling van die termiese afbreking van 'n enkele graan te verskaf, met identifisering van die ontbindingfases. Die ontbindingfases sluit in die aanvanklike en maksimum uitbreiding van die graan. Die analise het verder die vrystelling van gasse en verbindings uit die graan tydens verbranding bevestig, om die invloed van vrygestelde verbindings op die swellendeproses te beklemtoon, en die potensiaal van hierdie verbindings om swelling aan te dryf. Die 'cone calorimeter' eksperimente het groter skaal heel- en gemaalde millet-monsters betrek wat oor 'n staal substraat versprei is om die mate van termiese weerstand en gedrag in vergelyking met 'n enkele graan te bestudeer. Daar is gevind dat beide heel en gemaalde millet verbeterde ermiese weerstand aanbied vir die substraat deur die vorming van 'n uitgebreide selstruktuur met mikroskaal-openinge. Dit het die goeie potensiaal van millet getoon om beskerming aan staaldele in 'n brand te bied, en om as 'n vorm van passiewe beskerming gebruik te word. Boonop is verskeie voorlopige verf mengsels ontwikkel met die millet in kombinasie met toepaslike bindmiddels. Hierdie mengsels het voorlopige analise ondergaan vir die waarneming van aanvanklike termiese gedrag en swellende potensiaal. Hierdie werk het die kompleksiteit van swellende gedrag beklemtoon tydens ontwikkeling van betroubare swellende verwe en die groot invloed van komponente op swelling. Millet het bewys dat dit 'n baie belowende biomassa is vir die ontwikkeling van groen passiewe beskermingstelsels, en is in detail gekarakteriseer in hierdie tesis. Die primére probleem in verfontwikkeling was die gebrek aan samehang en die wegtrek tussen die monster en die substraat, wat verdere navorsing vereis. Masters 2025-05-02T10:36:14Z 2025-05-02T10:36:14Z 2024-12 Thesis https://scholar.sun.ac.za/handle/10019.1/131965 Stellenbosch University xiv, 128 pages : illustrations application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Fire resistant materials Paint, Fireproof Millets -- Thermal properties Coatings -- Thermal properties UCTD Vermeulen, Zara Stefanie Investigation into millet for use as an eco-friendly intumescent coating for passive fire protection |
| title | Investigation into millet for use as an eco-friendly intumescent coating for passive fire protection |
| title_full | Investigation into millet for use as an eco-friendly intumescent coating for passive fire protection |
| title_fullStr | Investigation into millet for use as an eco-friendly intumescent coating for passive fire protection |
| title_full_unstemmed | Investigation into millet for use as an eco-friendly intumescent coating for passive fire protection |
| title_short | Investigation into millet for use as an eco-friendly intumescent coating for passive fire protection |
| title_sort | investigation into millet for use as an eco friendly intumescent coating for passive fire protection |
| topic | Fire resistant materials Paint, Fireproof Millets -- Thermal properties Coatings -- Thermal properties UCTD |
| url | https://scholar.sun.ac.za/handle/10019.1/131965 |
| work_keys_str_mv | AT vermeulenzarastefanie investigationintomilletforuseasanecofriendlyintumescentcoatingforpassivefireprotection |