Razvoj in toplotnoizolacijske lastnosti trdih melaminsko-formaldehidnih pen

Kavšek, Miha (avtor), Krajnc, Matjaž (mentor)

V predloženi doktorski disertaciji je predstavljen razvoj trdih melaminsko-formaldehidnih pen za uporabo v toplotnoizolacijske namene. Uvod obsega zgodovinski razvoj ter osnovno teorijo procesiranja polimernih pen. Nadalje vključuje opis celične strukture in njen vpliv na lastnosti polimernih pen. Nato sledi pregled penilnih sredstev ter melaminsko-formaldehidnih pen. Predstavljeni so patenti ter osnovna teorija sinteze melaminsko-formaldehidne smole, ki je potrebna za izdelavo trdih melaminsko-formaldehidnih pen. Podana je osnovna teorija o visoko učinkovitih toplotnoizolacijskih materialih. Sledi opis prenosa toplote skozi toplotnoizolacijski material, ki vključuje podrobno razčlenitev posameznih načinov prenosa toplote k celokupni toplotni prevodnosti pri atmosferskih in vakuumskih pogojih. Podan je tudi razvoj numerične metode za nestacionarni prenos toplote. V eksperimentalnem delu je predstavljena sinteza melaminsko-formaldehidne smole ter postopek izdelave trdih melaminsko-formaldehidnih pen. Opisane so uporabljene metode za karakterizacijo pene. Določeni so začetni in robni pogoji ter uporabljene predpostavke za postavitev modela za opis nestacionarnega prenosa toplote. Rezultati in diskusija vključujejo karakterizacijo trde MF pene v smislu povprečne velikosti celic, opis vpliva formulacije (deleža penilnega in emulgirnega sredstva ter katalizatorja) na njeno gostoto ter efektivno toplotno prevodnost in kompresijsko trdnost v odvisnosti od gostote. Nadalje so podani rezultati določitve posameznih prispevkov načinov prenosa toplote (sevanje, prevajanje skozi polimerno matriko in prevajanje skozi zrak) k efektivni toplotni prevodnosti. Predstavljeni so rezultati izračuna nestacionarnega prenosa toplote skozi panel trde MF pene. Na koncu sledi še opis varnostnega vidika proizvodnje trdih MF pen ter možnost njihove reciklaže.

• Jezik: Slovenski jezik
• Ključne besede: trda melaminsko-formaldehidna pena, efektivna toplotna prevodnost, nestacionarni prenos toplote, kompresijska trdnost
• Vrsta gradiva: Doktorsko delo/naloga
• Tipologija: 2.08 - Doktorska disertacija
• Organizacija: FKKT - Fakulteta za kemijo in kemijsko tehnologijo
• Leto izida: 2024
• PID: 20.500.12556/RUL-159175
• COBISS.SI-ID: 202574851
• Datum objave v RUL: 02.07.2024

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Development and thermoinsulation properties of rigid melamine-formaldehyde foams

Izvleček

The submitted doctoral dissertation presents the development of rigid melamine-formaldehyde foams for use in thermal insulation applications. The introduction includes the historical development and the basic theory of polymer foam processing. It further includes a description of the cellular structure and its influence on the properties of polymer foams. This is followed by an overview of foaming agents and melamine-formaldehyde foams. Patents and the basic theory of the synthesis of melamine-formaldehyde resin, which is necessary for the production of rigid melamine-formaldehyde foams, are presented. The basic theory of highly efficient thermal insulation materials is given. This chapter includes description of heat transfer through thermal insulation material with detailed analysis of individual heat transfer modes to the overall thermal conductivity under atmospheric and vacuum conditions. The development of a numerical method for non-stationary heat transfer is also given. The experimental part presents the synthesis of melamine-formaldehyde resin and the production process of rigid melamine-formaldehyde foams. The methods used for foam characterization are described. Initial and boundary conditions are specified and assumptions used to set up the model to describe non-stationary heat transfer. Results and discussion include characterization of rigid MF foam in terms of average cell size, description of the effect of formulation (proportion of foaming and emulsifying agent and catalyst) on its density, and effective thermal conductivity and compressive strength as a function of density. Furthermore, the results of determining the individual contributions of the heat transfer methods (radiation, conduction through the polymer matrix and conduction through air) to the effective thermal conductivity are given. The results of the calculation of non-stationary heat transfer through a panel of rigid MF foam are presented. At the end, there is a description of the safety aspect of the production of rigid MF foams and the possibility of their recycling.

• Ključne besede: rigid melamine-formaldehyde foam, effective thermal conductivity, non-stationary heat transfer, compressive strength