Water → Benzene, ethenyl-, polymer with 1,3-butadiene

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Reaction Steps

To a 5-gallon reactor equipped with turbine agitator blades was added 5320 g of hexane, 1320 g of 33.0 wt % styrene in hexane, and 7776 g of 22.4 wt % 1,3-butadiene in hexane. To the reactor was charged 11.34 mL of 1.6 M n-butyllithium in hexane and 3.74 mL of 1.6 M 2,2-bis(2′-tetrahydrofuryl)propane in hexane. The batch was heated by applying hot water to the reactor jacket. Once the batch temperature reached 50° C., the reactor jacket was cooled with cold water. Ninety minutes after the addition of the catalyst, 402 g of the resulting living polymer cement was transferred from the reactor into a nitrogen-purged bottle, quenched by addition of 3 mL of isopropanol containing 0.3 g of 2,6-di-tert-butyl-4-methylphenol, coagulated with 3 liters of isopropanol containing 0.5 g of 2,6-di-tert-butyl-4-methylphenol, and then drum-dried. The Mooney viscosity (ML1+4) of the resulting polymer was determined to be 11.5 at 100° C. by using a Monsanto Mooney viscometer with a large rotor, a one-minute warm-up time, and a four-minute running time. As determined by gel permeation chromatography (GPC), the polymer had a number average molecular weight (Mn) of 120,300 g/mole, a weight average molecular weight (Mw) of 125,200 g/mole, and a molecular weight distribution (Mw/Mn) of 1.04. The 1H NMR analysis of the polymer indicated that the polymer had a styrene content of 19.7 wt % and a 1,2-linkage (butadiene unit) of 57.4%. As measured by differential scanning calorimetry (DSC), the polymer had a glass transition temperature (Tg) of −32° C. The properties of the resulting unmodified SBR are summarized in Table 4.

Provenance & Evidence