Bromobutyl Rubber Stopper, also called BIIR Stopper & Plug & Bung, as a medicine glass bottle sealing plug or cover, which made by compression tooling.
Brombutyl rubber (brominated butyl rubber) owns the basically saturated main chain of butyl rubber, so brombutyl rubber has a variety of performance characteristics. For instance, high physical strength, good cushioning effect, low-permeability, good characteristics of aging and weather resistance.
Butyl rubber is also called IIR, “short for Isobutylene Isoprene Rubber”. Butyl rubber has good performance of chemical stability and thermal stability, the most prominent among which is the air tightness and watertightness. Its air permeability is only a 1/7 of natural rubber, and 1/5 of styrene butadiene rubber, while the vapor permeability is 1/200 of natural rubber, and 1/140 of styrene butadiene rubber 1/140. So it is mainly used for manufacturing various inner tubes, steam pipes, water tires, dam bottom and gaskets and other rubber products.
In order to improve the poor blending of butyl rubber, halogenatedbutylrubber appeared in 1960. Advantages: halogenatedbutylrubber not only has better performance of air tightness, hat also owns properties of heat resistance, ozone resistance, aging resistance, chemical resistance, and shock absorption, electrical insulation. halogenatedbutylrubber can also be exposed to animal or vegetable oils or any other oxidizable chemicals.
Chlorobutyl rubber and Bromobutyl rubber belong tobutyl rubber derivatives by reacting butyl rubber, also known as halogenated butyl rubbers, which helps butyl rubbersto improve processing performance and expand a wider range of application.
1. Stabilizer Content: Bromobutyl rubber contains active Bromine element, which result in lower storage stability and easy self-vulcanization. Therefore, Bromobutylrubberusually need to be added stabilizer. However, chlorine element’s inertnessin butyl rubber is stronger than Bromine element’s, so chlorobutyl rubber has a higher storage stability and then there’s usually no need to add stabilizer to butyl rubber, which makes inner contents higher purify.
2. Antioxidant Content: Both of Chlorobutyl rubber and Bromobutyl rubber share the same proportion.
3. Property： As industrial products, there is no essential difference in properties.
4. Machinability： Bromobutyl rubber has high cure reactivity and it has a wide range of available curing systems. Common curing systems allare available for Bromobutyl rubber and the cure rate is faster. Industrial products have a high requirement for physical properties, which usually adopt Brominated phenolic resin, stearic acid, zinc oxide,thiazole and thiuram accelerator as curing systems. In early period, Pharmaceutical Stoppers also adopted the these systems, but with a period ofapplication, researchers found that these systemshave certain influence on compatibility between medical Stoppers and Pharmaceutical. At present, domestic Bromobutyl rubber usually choose sulphur for curing for high efficiency and low cost. However, Bromobutyl rubber has relatively low reactivity, which cause limitation of choosing curing systems. Besides, it still has strict requirement for manufacturing technique (relatively difficult). In the early days, phenolic resin, stearic acid and zinc oxide are usually used as curing system, contributing to good heat resistance. However, product’s extraction liquid is color-developing, which will affect Pharmaceutical clarity. Now, these curing systems are not used any more.
Advantages of Bromobutyl rubber Stopper Bromobutyl rubber’s curing location is more flexible, resulting in greater cure activity and better Cure compatibility. Bromobutyl rubber features: (1) Various available curing agents. Besides curing systems available for chlorobutyl rubber, Bromobutyl rubber also have other curing systems, like polyamine curing, which can avoid existence of sulfur, accelerant containing sulfur, and zinc oxide, ensuring higher purify. (2) High curing activity, fast cure rate, short curing time and small amount of vulcanizing agent. (3) High Cure compatibility with high unsaturated rubber (4) Formulation composition has small influence on curing(like, less affected by acid, slkali and humidity). Therefore Bromobutyl rubber is more suitable for curing injection in production process.
Compared with chlorobutyl rubber stoppers, Bromobutyl rubber stoppers have Better stability, longer life span and less impact on Pharmaceutical (especially low-molecular-weight Thrombin inhibitors