The influence of acrylic building blocks on polyurethane modified acrylic dispersions (PUMA)

Abstract (Swedish)

Akrylmonomerer i kombination med polyuretandispersioner skapar polyuretanmodifierade akrylatdispersioner, PUMAs. En PUMA är en typ av vattenbundet bindemedel som används i färg och lack. För att utvärdera hur de olika akrylaterna påverkar en PUMA, testades akrylat monomerer genom att svällas in i polyuretandispersioner. Egenskaperna hos en PUMA visade sig vara beroende på typ och mängd av akrylat. När 70 % av den totala solida mängden var akrylater hade det en stor påverkan på PUMA och speciellt filmegenskaperna. Sex olika akrylater testades och visade att egenskaper som hydrofobicitet och glasövergångstemperatur påverkar bindemedlet mest. Dessa sex monomerer svälldes in rena eller blandade och därefter polymeriserades in i polyuretandispersionerna. Akrylmonomerer användes också som viskositetsänkare i polyuretansyntesen, varvid allt dispergerades i vatten. Är monomerna för hydrofoba ökar dock reaktionstiden för polyuretansyntesen då reaktanterna har svårare att reagera in i polymerkedjan. Mängden och typen hos de akrylatmonomerna har en tydlig påverkan på PUMA och det är nödvändigt att använda en polyuretan med egenskaper som ger möjlighet att skapa polymerpartiklar vid dispersion, samt möjligheten att innehålla akrylaterna och bibehålla stabiliteten i bindemedlet.

Abstract

Acrylic monomers in combination with polyurethane dispersions form polyurethane modified acrylic dispersions, PUMA’s. A PUMA is a type of water borne binder used in lacquers and paints. To evaluate the effects different acrylic components have on a PUMA, swelling of acrylic monomers into polyurethane water dispersion was made for different acrylics. It showed that the properties of the PUMA can be related to amount and type of acrylic it contains. A 70% acrylic content of total solid content had a high impact on the PUMA, especially the dry film properties. Six different acrylics were tested and showed that properties such as hydrophobicity and glass transition temperature had a clear impact in the PUMA. These six monomers were used pure or blended in swelling process with PUD. Acrylic monomers were also used as viscosity reducer for the polyurethane in another process showing that too high hydrophobicity of the monomer decreased the possibility for the polyurethane reaction to proceed in a normal manner and increased the reaction time depended on the nature of the acrylic monomers. The type and amount of acrylic component have a clear influence on the properties of the PUMA and it is necessary to create polyurethane with the properties to form polymer particles when dispersed into water and the possibility to contain the acrylics and maintain stability.

Popular Abstract

Paints and lacquers both consist of a main component called the binder. The binder is what gives the product most of the desired properties, such as the stability, which is important for the shelf-life of the product, and the ability to form a dry film. Binders usually consist of two parts, a solid and liquid phase. More and more of the binders produced today have water as the liquid part. These binders are called water borne binders, and the properties of these largely depends on the solid part. As a solid part, usually polymers are used. Not all polymers can be used for binders, and there is ongoing research to better understand what polymers, and why these polymers are more suitable as a solid phase than others. With an increasing understanding of the interaction between polymers and water the possibility to engineer new and more potent binders also increases.
The usage and development of waterborne binders have increased in recent years. This is because they are a more environmentally friendly alternative to earlier products. Before, it was common to use binders with solvents as the liquid part. These solvents have a negative impact on the environment and are more and more phased out due to regulations and increasing costumer and supplier understanding.
The solid part polymers have special properties that is necessary when producing the binders. When the solid part polymer is blended into water the polymer will form many and very small particles. These particles form because of the immiscibility between water and polymers, just like oil form droplets when added to water. In this thesis, the properties of polymers used as the solid part in binders, have been evaluated. The polymers have these special properties that makes them suitable for binders. The inherent characteristics of each polymer used in this thesis differs. For each different polymer used, the properties of the final product, the lacquer have been evaluated. This was done to better understand how the polymers, and what characteristics of the polymers influence the binder.
Analyses were made on the binder in the solid/liquid-state and when a dry film had formed after application. The results showed that depending on the properties of the polymer components the properties of the binder, both as a polymer-water blend and as a dried film, changed. It was possible to relate the polymer characteristics to the properties of the product. These binders have a wide variety of end-uses and the water-borne binders should be prioritized since they have less environmental impact compared to solvent based. The polymers in the binder need to have the right properties so that the stability and the film-forming properties fulfill expectations.

• author: Nilsson, Tim
• supervisor: Peter Linton; Baozhong Zhang
• organization: Centre for Analysis and Synthesis
• course: KTE720 20171
• year: 2017
• type: H2 - Master's Degree (Two Years)
• subject: Technology and Engineering
• keywords: polymer technology, polymerteknologi
• language: English
• id: 8925995
• date added to LUP: 2017-09-22 09:53:50
• date last changed: 2017-09-22 09:53:50