Researchers at TWI, Cambridge, UK, have created a silsesquioxane pre-polymer that can enhance abrasion resistance in a variety of end use applications.

Vitolane technology uses structures of repeat units of tri-functional silanes in ladder or cage structures. It was developed from TWI’s work on inorganic-organic hybrid nanocomposite coatings.

‘We recognised that the inorganic component was incomplete and had not fully gone through to cure during our processing. Vitolane was born out of that, where we were trying to complete the inorganic component of the network,’ explains Alan Taylor, Principal Project Manager at TWI.

Joining the inorganic tri-functional silanes via siloxane bonds is the central component of the formation of an oligomeric silsesquioxane. The silane has a fourth organic group that can give a range of other characteristics (an acrylate silane can be UV cured, for example, or a phenyl group silane can have improved high temperature stability).

If bonded correctly, such that all the siloxane polymerisation occurs inwardly leaving the organic component sticking out, the molecular weight of the oligomer stays low and discrete ladder or cage structures are generated. This forms a liquid which can be incorporated into a coating formulation to endow it with a quick UV cure capability and abrasion resistance, while being solvent-free, making it more environmentally friendly than traditional hard coats. The Vitolane technology can create a coating with several properties.

‘People have a catalogue of ingredients available to them that give different attributes to their products,’ says Taylor.

These attributes are built into a single oligomer, allowing formulators to create blends specifically targetted at particular applications. The pre-polymer has demonstrated a Taber test haze result of three per cent, compared to a typical value of 50% for polycarbonate or 10% for a premium hard coat.

Taylor would like to see the technology used to manufacture materials with properties between glasses and plastics, such as in windscreens, which could have a built-in anti-misting capability.