Besides the grafting level, other significant parameters are: the catalyst (type/amount) and the crosslinking environment (humidity, temperature). Water is essential for the final crosslinking step. The water molecules have to penetrate the polymer and must inititate the hydrolysis reaction which is followed by condensation of silanol species (crosslinking through chemically stable Si-O-Si bonds). The highest possible amount of water molecules on the polymer surface in combination with high temperatures are an optimal solution for the penetration of water and the crosslinking reaction. As a logical result, the most effective and fastest way is the use of a waterbath (highest possible amount of water molecules) at elevated temperatures (80-90°C, or ambient pressure). By using higher pressure the speed can be increased significantly. However, this method needs some extra investment. Another option is using steam. This way is slower than the water bath system (higher temperatures but fewer water molecules). Crosslinking under ambient conditions is the most cost effective process with regards to equipment . In this case, the amount of water (e.g. at 23°C/ 50% rel. Humidity) is significantly lower compared to a water bath. As the temperatures are lowest, too, it is definitely the slowest way to cure the polymer product.

Which polymers might be chemically modified using silanes ? PE (polyethylene) as well as PE-based copolymers (e.g. EVA) are the most commonly used polymer grades for silane crosslinking technology. When using peroxide, the main question is the sensitivity of the polymer towards free radicals. Once formed, these can either recombine, add vinyl products, or even degrade. For this reason, a polymer such as PP isn‘t suitable for this technique. Depending on the polymer structure a wide variety of Dynasylan^® products may be suitable for a chemical modification.