In emulsion polymerization, the replacement of standard monomers with bio-based monomers requires a firm understanding of the total system, if it is to be formulated properly. The HLD-NAC approach can be used to characterize the constituents in a polymer emulsion so that, more rational adjustments can be made to the surfactant system, while maintaining stability and performance.
The Hydrophilic Lipophilic Difference - Net Average Curvature (HLD-NAC) theory in a defined emulsion system, is used to make profound predictions about:
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Type of emulsion (o/w, w/o), and
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Efficiency of surfactant
HLD-NAC allows for the selection of the optimal surfactant to obtain the desired type of (micro-) emulsion by taking the following parameters into account:
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Monomer or polymer number (EACN)
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Temperature
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Salinity, and
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Co-solvents
The previous article on efficient selection of bio-based surfactants, described a practical application of HLD-NAC for emulsion polymerization. There, a bio-based surfactant was selected to emulsify a blend of monomers. This article sets out to demonstrate the use of HLD-NAC in replacement of the water-soluble co-monomers used in an emulsion polymerization.
Let's begin by understanding the effect of replacing acrylic acid with itaconic acid in a well-known emulsion polymerization system.
Replacing Acrylic Acid with Itaconic Acid
VLCI participated in the BioQED project (www.bio-qed.eu), a European project for developing bio-chemicals from renewable sources. Its main goal is to open new industrial routes for the production of important chemicals from renewable sources rather than traditional petrochemical sources.
In this framework, an entrepreneurial consortium was built. It's joint ambition was to generate hard evidence and collect all the technical and economic key design parameters needed for investment decisions for the first industrial production plants of the bio-based building blocks: 1,4 butanediol (BDO) and itaconic acid (IA). The consortium is based on strong industrial leadership on both of the selected products and covers the full supply chains for bio-based BDO and IA.
In this example, itaconic acid (IA) is used to replace acrylic acid (AA) in the copolymerization reaction of Butyl Acrylate (BA) and Vinyl Acetate (VA) (30:70). It is a well-known system for emulsion polymerization.
High Throughput Preparations
HLD scans are performed in accordance with the theory to assess the HLD behavior of AA and IA. Also, the scans are executed, if adjustments on the HLD balance need to be made to preserve the equilibrium of the system after the IA replacement.
High Throughput Preparations
» Continue reading to understand how 'HLD-NAC' technology is an efficient approach towards the replacement of standard monomers with bio-based monomers!