Tags: toxicity

What are the four types of condensation curing systems of RTV Silicones?

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Link: http://adteputek.com/b2evolution/blog2.php/2009-06-07-what-are-the-four-types-of-co

Different condensation curing systems are named according to the leaving group of the crosslinker that is used in their formulation. Therefore acetoxy-cure mechanisms give off acetic acid, alkoxy-cure mechanisms give off alcohols and oxime-cure mechanisms give off dimethyl ketoxime (DMKO). With these condensation by-products lies the source of a number of problems for silicones. Acetic acid is corrosive and therefore acetoxy-cure systems are unsuitable for chemically sensitive applications such as electronics. DMKO is less corrosive but can cause damage if trapped in close vicinity to sensitive components, for example if an oxime-cure silicone is applied as an encapsulant. DMKO also has toxicity issues, which limits its acceptability for many customers. Alcohol-cure adhesives avoid these problems by producing relatively-benign ethanol as their by-product, but react slowly and are less temperature-stable of an adhesive than acetoxy-cure mechanisms.The fourth type of condensation cure system is Acetone but is more expensive but worthwhile only if around sensitive components.