Butyl Rubber typically contains about 98% polyisobutylene with 2% isoprene distributed randomly in the polymer chain. To achieve high molecular weight, the reaction must be controlled at low temperatures (-90 to -100 degC).The reaction is highly exothermic.utyl Rubber typically contains about 98% polyisobutylene with 2% isoprene distributed randomly in the polymer chain. To achieve high molecular weight, the reaction must be controlled at low temperatures (-90 to -100 degC).
There may be no single cause of bipolar disorder (aka manic depression). Instead, research indicates the causes of bipolar disorder are probably a combination of biochemical, genetic and environmental factors that may trigger and perpetuate the chemical imbalances in the brain.
And while the causes of bipolar disorder are still unknown, there are a number of factors that are believed to play a role, including genetics, brain chemicals, environmental factors and sometimes medical illnesses.Read about: 1  Genetics. 2  Brain chemicals.3  Environmental.4  Medical illness. 5  Pregnancy.nd while the causes of bipolar disorder are still unknown, there are a number of factors that are believed to play a role, including genetics, brain chemicals, environmental factors and sometimes medical illnesses. Read about: 1  Genetics. 2  Brain chemicals. 3  Environmental. 4  Medical illness.