| 摘要 |
The polysyrene having a dispersion degree of below 1,1 and molecular weight of 2,000-2,000,000 is obtained by polymerizing styrene monomer, cyclo hexane, tetrahydrofuran and reaction initiator under nitrogen atmosphere (1.5-3 atms.). The mole ratio of cyclohexane to styrene monomer is 10-15:1, and that of tetrahydrofuran to initiator is 15-20:1. The initiator is obtained by dissoving at least one organic lithium compound selected from the group composed of sec-buthyl lithium, tert-buthyl lithium and n- buthyl lithium into hexane. The resin is used as a standard specimen for analytical instruments such as gel permeation chromatography.
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