Silane crosslinking

Silane crosslinking is introduced through silane coupling agent in the polyethylene, increase the intensity of the polyethylene, aging resistance and other characteristics.
Method of silane crosslinked polyethylene technology since the 60 s was got rapid progress, won a wide application.Silane crosslinked polyethylene in the industry now there are three main kinds of technological methods: two steps process (also called SioplasE), one-step production process (also called MonosilR) and vinyl silane copolymers process, including vinyl silane copolymers technology combines two steps, and many advantages of the one-step method, has more advantages, but, in the process of three kinds of crosslinking reaction is through the blend with silane alcohol condensation catalyst of silane modified polyethylene soak in warm water or water vapor, crosslinking needed moisture diffusion came in from the outside world.Due to the hydrophilic polyethylene, water in polyethylene, diffusion is slow, the crosslinking is very slow, and the products of the wall is thicker, the longer the crosslinking time.For example, in 80 ℃ warm water crosslinking, to achieve the same degree of crosslinking, 8 mm thick sheet should be 120 h, 15 mm thick sheet will be expected to 260 h, 22 mm thick sheet should be 1000 h.The above data is crosslinking of silane grafted PE speed data, vinyl silane crosslinking of copolymer faster than crosslinking of silane grafted PE speed lower than 3 ~ 4 times.This to the industrialized production of the silane crosslinked polyethylene caused great inconvenience, so how to solve the problem of slow crosslinking became a big problem in the silane crosslinking technology.

(source:http://www.ac-chem.net/news/crosslinking-9078.html)