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.
But it occurs more often in relatives of people with bipolar disorder. In most people with bipolar disorder, there is no clear cause for the periods (episodes) of extreme happiness and high activity or energy (mania) or depression and low activity or energy (depression). The following may trigger a manic episode: Childbirth.