About Silicone Surfactants

Silicone surfactants or additives are generally categorized based on the molecular structure of polymers as follows:

Polyether-modified Siloxane Copolymers

Trisiloxanes

Reactive Silicone Additives

1. Polyether-modified Siloxane Copolymers

The majority of silicone additives fall into this category, featuring either side-chain (grafted) or linear structures. By varying the number of polyether and siloxane segments and their degree of polymerization, silicone products with different properties can be obtained. These polyether-modified siloxanes are highly effective in various coatings even at low dosages. The siloxane portion of the molecular structure provides low surface tension and high surface activity. The performance of polyether-modified siloxanes depends on the type and amount of polyether they contain.

• A molecule with a high siloxane content offers excellent slip and scratch resistance. If the siloxane content is very high, the additive can function as a defoamer and release agent.

• Siloxanes containing polyethylene oxide (EO) exhibit good compatibility with water-based coatings, even being water-soluble. These additives enhance wetting, flow, and leveling in water-based coatings while maintaining gloss and ensuring good recoatability.

• If the polyether portion contains polypropylene oxide (PO), the copolymer will have good compatibility with solvent-based or high-solid coatings/inks and can act as a flow and leveling (anti-cratering) agent in formulations.

2. Trisiloxanes

Grafting polyether groups onto heptamethyltrisiloxane results in trisiloxanes with unique properties. These are excellent wetting and spreading agents, often referred to as "super spreaders," widely used in pesticide additives and providing wetting synergies in water-based coatings and inks.

3. Reactive Silicone Additives

While most silicone additives function through non-chemical means, some reactive silicone additives possess reactive groups that can chemically bond with resins, permanently modifying the coating. These products typically have end-capping groups such as hydroxyl or acrylic groups.