BioLoop Technology for Aqueous White Dispersions
- jessicawieland
- 2 days ago
- 3 min read
Written by: Dr. Andrew Richards, Technical Consultant & Dr. Cathy Cooper, Technical Manager
Introduction
Titanium dioxide continues to be the cornerstone pigment for achieving opacity and brightness in paints, coatings, and inks. As the coatings industry increasingly transitions from solvent-based to water-based technologies—driven by environmental regulations and sustainability goals—the challenge of achieving effective pigment dispersion in aqueous media becomes even more significant. The ideal particle size for high-opacity applications remains around 0.25–0.3 µm, but surface treatments alone rarely deliver the level of colloidal stability required in aqueous environments, making the choice of dispersing technology critical for performance.
At Lankem, we are addressing this challenge through our unique BioLoop technology – effective dispersing agents designed to blend sustainability and performance. These dispersants not only provide superior pigment stabilization and deflocculation but also incorporate high levels of renewable carbon, supporting the industry’s drive toward more sustainable solutions. This article will share insights from our initial laboratory studies comparing BioLoop-based dispersants with leading market alternatives in water-based titanium dioxide dispersions.
Products Tested
Sodium Polyacrylate
40% active
0% bio-based
Lansperse RPS25
80% actives
>98% bio-based
Lankem’s BioLoop technology is built around a unique architecture: two hydrophobic segments derived from vegetable oils are linked by a hydrophilic loop sourced from molasses. This design offers flexibility, with multiple options for the oil-based hydrophobic sections and three available chain lengths—short, medium, and long—allowing tailored performance for different applications.
Our laboratory evaluations showed that the medium chain length provided the best results for dispersing titanium dioxide in water-based systems. The data presented here focuses on two BioLoop dispersants: Lansperse BIO801, which uses soybean oil, and Lansperse RPS25, based on rapeseed oil. For comparison, we benchmarked these against a conventional market-standard dispersant—a sodium polyacrylate supplied at 40% active content in water, with no renewable carbon contribution.
Experimental
Component (Percentage as supplied) | Sodium Polyacrylate | Lansperse BIO801 | Lansperse RPS25 |
|---|---|---|---|
Dispersant | 1.30 | 0.65 | 0.65 |
Dfoam | 0.01 | 0.01 | 0.01 |
Biocide | 0.10 | 0.10 | 0.10 |
Tioxide® TR92 | 65 | 65 | 65 |
Deionised Water | To 100% | To 100% | To 100% |
Table 1: Aqueous formulations of titanium dioxide and a range of dispersants at a pigment loading of 65 % w/w and a dispersant loading of 1 % actives w/w relative to the pigment.
Pre-mixes were made using a Silverson at 1000 rpm, adding ingredients as specified in Table 1 with the dispersant, water, defoamer and biocide mixed first before addition of pigment over 10 min. Once all the pigment was added, further homogenisation was performed at 4000 rpm for 15 min. Viscosity was measured using a DIN 4 flow cup after 24 hours and after storage at room temperature at increments thereafter.
Results
Graph 1: Millbase viscosity over time for a range of titanium dioxide dispersions using different dispersing agents. The sample containing sodium polyacrylate split into two layers after 36 days at room temperature and storage was discontinued.
Lansperse BIO801 and Lansperse RPS25 both gave fluid millbases, with the rapeseed BioLoop variant giving a lower viscosity than both the soybean variant and the sodium polyacrylate. This indicated good initial wetting and dispersing capabilities from the bio-based products, giving good performance in comparison to the synthetic option.
On storage at room temperature, the BioLoop dispersants retained a stable viscosity profile over the course of the experiment. The viscosity of the sodium polyacrylate system dropped steadily on storage, and the sample separated into two layers at 36 days. This suggested that desorption or ionic interactions are occurring in the sodium polyacrylate system that interfere with the ability of the dispersant to keep the pigment particles separated. The resulting flocculation of the pigment reduces the Brownian motion of the particles and therefore allows gravity to become the dominant force in the system, leading to settling of the dense pigment to the bottom of the sample.
Conclusion
Following a laboratory study by Lankem into the performance of bio-based dispersants in aqueous dispersions of titanium dioxide pigment, two products were shown to give excellent performance in comparison to a conventional sodium polyacrylate dispersant. Lansperse BIO801, based upon soybean oil, gave a comparable initial viscosity to the market standard and retained a stable viscosity on storage at room temperature. Lansperse RPS25, based upon rapeseed oil, offered the best performance of the dispersants tested, with a lower viscosity millbase that retained the protection against particle flocculation and settling.
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