what is the difference between chlorobutyl and bromobutyl rubber stoppers
Leave a message
Currently, there are two main types of halogenated butyl rubber commonly used in the world for the production of medicinal rubber stoppers: chlorinated butyl rubber and bromobutyl rubber. Europe and the United States are accustomed to using bromobutyl rubber to make medicinal bottle stoppers. In the early days of Asia, most of them were chlorinated butyl rubber. So far, more than 90% of medicinal butyl rubber stoppers in Japan and Taiwan are still processed using chlorinated butyl rubber.
Nowadays, the international community prefers chlorination. Because bromine is more active than chlorine, the stability and safety of chlorinated rubber stoppers are relatively high. In the past, most freeze-dried varieties used bromobutyl rubber stoppers, which were sterilized at 121 degrees. There was no problem. If the temperature is higher, you should consult the rubber stopper manufacturer. However, when brominated rubber stoppers are used, the clarity of the product is likely to be poor after redissolution after acceleration or placement. Pay attention to this impact. Chlorinated rubber stoppers have better product reconstitution clarity and have not been found to have any impact on product quality.
In the end, the stability of the two types of rubber stoppers must be judged through experimental investigation. Generally, when testing the compatibility of packaging materials, it is impossible to only make one of the packaging materials and do both chlorination and bromination. If there is no obvious difference within the set time, you can choose whatever you want. Either choose chlorination with better stability, or if chlorination is really more expensive than bromination, choose bromination.
Some people believe that chlorinated butyl rubber stoppers and bromobutyl rubber stoppers have different characteristics because of the different halogen atoms in the rubber. Bromobutyl rubber stoppers can use low content of vulcanizing agents and do not need to add plasticizers. Compared with chlorinated butyl rubber stoppers, they are cleaner and have less impact on drugs. Compared with bromobutyl rubber stoppers, chlorinated butyl rubber stoppers have better heat resistance and are less prone to adhesion after high-temperature sterilization.
Comparison of two types of rubber:
1.1. Both chlorinated butyl rubber and bromobutyl rubber are modified products of butyl rubber, collectively called halogenated butyl rubber. The purpose of modification is to improve its processing performance and expand its application scope. Butyl rubber is prepared by dissolving butyl rubber in alkanes or cycloalkanes and performing a halogenation reaction under stirring. The reaction mechanism is relatively complex, mainly addition and substitution. Bromobutyl rubber contains about 2% bromine, and chlorinated butyl rubber contains 1.1% to 1.3% chlorine. After halogenation of butyl rubber, the vulcanization speed is greatly improved, the blendability and vulcanization performance with other rubbers are improved, and the adhesion is also significantly improved.
1.2. Stabilizer content: Since the bromine element in bromobutyl rubber is relatively active, has low storage stability, and is prone to self-sulfurization, it is necessary to add a stabilizer (usually epoxy soybean oil, with a content of
1.3) to the rubber. % by weight); while the chlorine element in chlorobutyl rubber is more inert than bromine, has high storage stability, generally does not add stabilizers, and has a higher intrinsic purity than bromide rubber.
1.3. Anti-aging agent content: The two rubbers are equivalent.
zle.
1.4. Performance: As industrial products, there is no essential difference between the two.
1.5. Processing performance: Butyl bromide has high vulcanization activity and a wide range of vulcanization systems. General vulcanization systems can be used, and the vulcanization speed is accelerated. Industrial products usually use brominated vulcanization because of their higher requirements on physical properties of the product. Phenolic resin, stearic acid and zinc oxide are used as the vulcanization system or thiazole and thiuram accelerators are used as the vulcanization system. The above-mentioned system was also used in the early production of medicinal rubber stoppers. However, after use and subsequent research, it was found that the above-mentioned systems affected the compatibility of rubber stoppers and drugs.
