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研究了用Nd(OR)_3催化体系合成的聚异戊二烯(PIp)的分子量、分子量分布及其微观结构。结果表明,PIp的分子量高,[η]一般为5～10dL/g,主要受Al(i-Bu)_3用量和聚合温度的影响。在Al/Nd≤20(摩尔此)、室温下聚合时,可以获得“活的”聚合物。其分子量分布宽((?)_w/(?)_n=6～10)是因体系中活性种不单一,既有增长活性高并生成高分子量PIp的固相活性中心,又有活性低且生成低分子量PIp的可溶性活性中心。PIp的顺式-1,4含量约为95％,其余为3,4-链节。
The molecular weight, molecular weight distribution and microstructure of polyisoprene (PIp) synthesized by Nd (OR) 3 catalytic system were studied. The results showed that the molecular weight of PIp is high, [η] is generally 5 ~ 10dL / g, which is mainly affected by the amount of Al (i-Bu) _3 and the polymerization temperature. When Al / Nd <20 (mole), polymerized at room temperature, a “living” polymer can be obtained. Its molecular weight distribution is wide ((?) _ W / (?) _ N = 6 ~ 10) because of the active species in the system is not a single, both high growth activity and generate high molecular weight PIp solid activity center, Soluble active site of low molecular weight PIp. The cis-1,4 content of PIp is about 95% and the balance is 3,4-mer.