摘要
将对异戊二烯聚合具有高选择性的稀土催化剂1~5,在助催化剂有机硼盐和烷基铝的作用下,用于催化硅烷基保护的极性共轭双烯单体IP-OTBS均聚合,制得了顺式1,4-结构单元含量最高为98.5%和3,4-结构含量最高达82.2%的聚(IP-OTBS).PNP-型稀土钇催化剂2催化IP-OTBS与1,3-丁二烯(BD)、异戊二烯(IP)无规共聚合,制备出了极性基团含量分别为10.2%和16.7%的顺丁橡胶和异戊橡胶.这些极性聚合物在四丁基氟化铵的作用下脱除硅烷基保护基团,制得醇羟基功能化的顺丁橡胶和异戊橡胶.
Random incorporation of polar groups into polyolefins via coordination copolymerization has made a great progress in the past decades.In contrast,the preparation of polar functionalized conjugated diene rubbers receives less attention,although the polar groups play an important role in improving the mechanical properties of green tire.In this work,one kind of polar conjugated diene mononer IP-OTBS is prepared.Then,a series of rare earth metal complexes 1‒5,which show different selectivities for isoprene polymerization,are utilized to initiate the homopolymerization of IP-OTBS in the presence of cocatalysts[Ph_(3)C][B(C_(6)F_(5))_(4)]and AliBu_(3).Among them,complexes 1 and 2 still show high cis-1,4 selectivity(>98%)for IP-OTBS polymerization and,in contrast,the maximum value of 3,4 selectivity is 82.2%achieved by complex 3.Complexes 4 and 5,which show higher 3,4 selectivity(>98%)for isoprene polymerization,show moderate 3,4 selectivity(67.6%)and inert,respectively,under the same conditions.The copolymerizations of IP-OTBS with isoprene and butadiene using complex 2 generate the functional polybutadiene and polyisopene with cis-1,4 content of 10.2 mol%and 16.7 mol%,respectively.The bulky tert-butyldimethylsilane masked polybutadienes are readily transformed into the hydroxyl group functionalized polybutadienes or polyisoprene via the reaction with Bu4NF.Finally,we demonstrate that the polar group functionalized conjugated diene rubbers could be obtained via the stereoselective(co)polymerization of IP-OTBS by using rare-earth metal catalysts.
作者
汪骐远
黄建铭
李世辉
崔冬梅
Qi-yuan Wang;Jian-ming Huang;Shi-hui Li;Dong-mei Cui(State Key Laboratory of Polymer Physics and Chemistry,Changchun Institue of Applied Chemistry,Chinese Acadamy of Sciences,Changchun 130022;School of Applied Chemistry and Engineering,University of Science and Technology of China,Hefei 230026)
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2022年第5期474-481,共8页
Acta Polymerica Sinica
基金
国家自然科学基金(基金号51773193,52073275)资助项目.
