Allyl bromide → Isoprene butadiene

Participants

Reaction Conditions

Reaction Steps

In this experiment, an isoprene-butadiene copolymer was synthesized using an alcohol modified neodymium catalyst system with a different catalyst component molar ratio than that described in Example 3. In this procedure, a one gallon (3.78 liter) reactor was charged with 1,088 grams of hexane containing 93.5 grams of butadiene and 668 grams of 1.23 molar diisobutylaluminum hydride (DIBAH) in hexane (i.e., 25% weight percent DIBAH). To this solution was added 26.22 grams of n-butanol with stirring and with temperatures maintained at 20° C. After stirring for thirty minutes, 107.5 grams of a 10.1% neodymium solution (neodymium neodecanoate), dilute with 158 grams of dry hexane, was charged to the reactor. The solution was stirred for another thirty minutes after which time 21.4 grams of allyl bromide was added. The cooling was stopped and the mixture allowed to warm up to ambient (and above) temperature. After the exotherm subsided, requiring about one hour, the catalyst solution was heat aged at 65° C. for ninety minutes. The aged catalyst was then cooled and stored in a dry container under nitrogen. The catalyst prepared had a [butanol-DIBAH] Nd-allyl bromide-butadiene molar component ratio of [4.7-15.5]-1-2.35-23, respectively, and a concentration of 0.025 molarity with respect to the neodymium.

Provenance & Evidence