龚狄荣1,2，胡锦昌1,2，毕吉福1，董为民1*，姜连升1，张学全1
(1.中国科学院长春应用化学研究所，长春 130022：2.中国科学院研究生院，北京 100039)
Bridgestone公司近年发表了一系列以亚磷酸酯及其衍生物为配体的铁、铬系催化剂在较高的温度下(50℃)制备1,2-聚丁二烯的专利[1,2]。本课题组[3]研究了以三苯基磷酸酯(TPP)为配体的铁系催化剂催化聚合丁二烯的规律，发现随聚合温度的升高，聚合速率有明显提高，聚丁二烯的1,2-含量和1,2-聚丁二烯的立构规整性也有明显地提高。
本文在前述工作基础上，考察了以TPP为配体的铁系催化剂中烷基铝的结构、溶剂性质对丁二烯聚合的影响规律和以TPP为配体的铬系催化剂的聚合反应规律。 (1) Fe(acaac)3/AlR3/TPP catalyst
烷基铝作用下的催化剂活性高于氢铝作用下的催化剂活性，烷基铝作用下得到的是1,2含量较高的结晶性聚丁二烯，烷基氢铝作用下得到的是1,2含量较低的无定形聚丁二烯。 Table 1 Effect of AlR3 in hexane at 50℃for 4h，[BD]=1.85M, [Fe]=0.56mM, Fe/Al/TPP=1:30:4.
AlR3 | Yield/% | Polymer appearance | Tm/℃ | Xc/% | cis-1,4/% | trans-1,4/% | 1,2/% |
Al(i-Bu)3 | 23.6 | Crystalline | 179.5 | 69.7 | 8.1 | 91.9 |
AlEt3 | 18.5 | Crystalline | 175.4 | 39.9 | 14.4 | 85.6 |
Al(i-Bu)2H | 17.6 | Amorphous | none | none | 29.7 | 1.8 | 68.5 |
AlEt2H | 15.8 | Amorphous | none | none | 32.9 | 1.1 | 66.0 |
| | | | | | | |
在不同的溶剂中生成的聚丁二烯均以1,2结构为主，1,2含量相差不大。在饱和烷烃溶剂中催化剂的活性远高于芳烃溶剂中的催化剂活性。
Table 2 Effect of solvent at 50℃for 4 h ，[BD] = 1.85 M, [Fe] = 0.56 mM, Fe/Al/TPP = 1:3
0:30.
Solvent | Yield/% | Tm/℃ | Xc/% | 1,2/% | trans-1,4/% |
Hexane | 72.4 | 168.8 | 6.3 | 94.5 | 5.5 |
Cyclohexane | 81.5 | 172.5 | 19.6 | 87.9 | 12.1 |
Heptane | 86.5 | 171.3 | 10.6 | 91.9 | 8.1 |
Toluene | 20.4 | 172.5 | 19.6 | 88.9 | 11.1 |
Dichlorobenzene | 11.9 | 172.3 | 3.7 | 90.1 | 9.9 |
| | | | | |
(2) Cr(acaac)3/AlR3/TPP catalyst
Al(i-Bu)3作为助催化剂时的催化活性远高于两种氢铝作用下的催化剂活性；三种烷基铝均得到1,2含量高于80%的聚丁二烯；对于烷基铝作用下得到的聚丁二烯，烷基氢铝所得到的聚丁二烯分子量较高而分子量分布稍宽。
Table3 Effect of AlR3 in hexane at 50 ℃; [Bd] = 1.85 M, [Cr] = 0.56 mM，Cr/Al/TPP = 1:30:5.
AlR3 | Yield/% | Mn×10-3 | Mw/Mn | 1,2/% | trans-1,4/% | Cis-1,4/% |
Al(i-Bu) 3 | 47.7 | 6.11 | 1.62 | 84.4 | 15.6 | 0 |
Al(i-Bu) 2H | 9.3 | 60.1 | 3.37 | 82.2 | 3.7 | 14.1 |
AlEt2H | 9.2 | 46.6 | 3.26 | 85.5 | 3.8 | 10.7 |
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参考文献
[1] Steven Luo．Iron-based catalyst composition for the manufacture of syndiotactic 1,2-polybutadie
-ne．US 6610804，2002
[2] Steven Luo．Method of preparing syndiotactic 1,2-polybutadiene with a chromium-based catalyst
system．US 5919875，2002
[3] 胡雁鸣，董为民，姜连升等．铁系催化剂上合成高乙烯基聚丁二烯的研究．催化学报，2002 25(8)：665
Investigation on butadiene polymerization with transition metal
catalysts with triphenylphosphate as the third component
Dirong Gong1, 2 , Jinchang Hu1, 2, Bifu Bi1, Weimin Dong1*, Liansheng Jiang1,
Xuequan Zhang1
(1 Changchun Institute of Applied Chemistry, the Chinese Academy of Science, Changchun 130022; 2 Graduate School of the Chinese Academy of Science, Beijing 100039)
Abstract: The effects of the structure of alkyl aluminums and the nature of solvent were examined in the butadiene polymerization in the presence of iron-based catalyst with TPP as the third component. Crystal polybutadiene with higher 1,2-content ( 85%) was obtained with trialkylaluminum, while amorphous polymer with lower 1,2 content (ca. 70%) was obtained with dialkylaluminum hydride; catalysts activities in alkane was higher than that in arene. Chromium-based catalyst with TPP as the third component was also investigated in butadiene polymerization. The produced polymer had 1,2-content of about 80%. Dialkylaluminum hydride as cocatalyst provided 1,2-polybutadiene with higher Mn and higher molecular weight dispersion, when compared the results with trialkylaluminum.
Key words: Transition metal catalysts Triphenylphosphate Al-compounds 1,2-Polybutadiene
.
