Addition cure system and condensation-based system...

In uncured state of silicone rubber, it is a highly-adhesive gel or liquid. In order to convert to a solid, it must be cured, vulcanized, or catalyzed. This is normally carried out in a two stage process at the point of manufacture into the desired shape, and then in a prolonged post-cure process. It can also be injection molded.Silicone rubber may be cured by a platinum-catalyzed cure system, a condensation cure system, a peroxide cure system, or an oxime cure system.       Addition cure system---------In a platinum-based system, also called an addition system (because platinum is added to the system as a catalyst and there are no byproducts) two separate components must be mixed to catalyze the polymers: the one component contains a platinum complex which must be mixed with the second, a hydride- and a vinyl-functional siloxane polymer, creating an ethyl bridge between the two. Such silicone rubbers cure quickly, though the rate of or even ability to cure is easily inhibited in the presence of elemental tin, sulphur, and many amine compounds. This platinum-based system has many merits, such as almost nil shrinkage(not more than 0.1%), high chemical resistance to aggressive components of some types of resins, good tear strength, high degree of precision in reproduction, high demensional stability over time and non-deformability, high resistance to high temperatures and aging, excellent non-stick effect and food grade(environmental, odorless and nontoxic).   Condensation-based system----------In a condensation system, also called an RTV (room-temperature vulcanizing) system, an alcoxy crosslinker exposed to ambient humidity (i.e., water) experiences a hydrolysis step and is left with a hydroxyl group. This group then participates in a condensation reaction with another hydroxyl group attached to the actual polymer. A tin catalyst is not necessary for the reaction to occur, though it increases the rate of the reaction and therefore decreases the cure time. Such a system will cure at room temperature and (unlike the platinum-based system) is not easily inhibited by contact with other chemicals. Acetoxy tin condensation is one of the oldest cure chemistries used for curing silicone rubber, and is the one used in household bathroom caulk.   Shenzhen Hong Ye Jie technology Co. Ltd provides for our customers with first-grade silicone rubber. we always regard customers’demands as the very mission that we should try to pursue heart and soul. If you wanna obtain more details of Hongye silicone rubber or related services, please enter our cellphone entrance(http://m.szrl.net) or computer website（http://www.szrl.net ) . (FAX: 89948030 TEL: 086-755-89948019 086-755-89948006 EMAIL: info@szrl.net).