使用金屬茂/有機鋰觸媒系統來氫化SBS嵌段共聚物

Metallocene/Organolithium Catalyst Systems for the Hydrogenation of SBS Copolymers

蔣見超(Raymond Chien-Chao Tsiang) ； 楊文賢(Wen-Shen Yang)

《化學》 57卷1期 (1999/03) Pp. 81-88

https://doi.org/10.6623/chem.1999011

摘要

當不同的金屬茂觸媒，包括bis (ŋ^5-cyclopentadienyl) cobalt、bis (ŋ^5-cyclopenadienyl) nickel和bis(ŋ^5-cyclopentadienyl) titanium dichloride ，配合上不同的還原劑，包括正丁基鋰、苯基鋰、或三乙基鋰的時候，他們對SBS共聚合物的氫化飽合反應有不同的催化效率。其中，以bis(ŋ^5-cyclopentadienyl)cobalt (Cp_2Co) 結合正丁基鐘(n-BuLi) 所構成的觸媒系統被發現具有最良好之催化活性。氫氣的壓力與CP_2CO/正丁基鋰的比例皆會造成影響。實驗數據顯示，此反應存在著一個最適的氫氣壓力值以及最適的金屬茂/還原劑比例。從此觸媒系統之紫外線光譜獲得的數據指出，原來配位在CP_2CO的Cp 被丁基取代形成主要的觸媒物種CpCoBu 。此氫化反應的動力機制乃藉由使用FTIR 光譜監看此共聚物中polybutadiene 部份的雙鍵飽和程度而得到。

關鍵字

氫化 ； 金屬茂觸媒 ； 有機鋰 ； 正丁基鋰

並列摘要

The cobaltocene/n-butyllithium catalyst system was found very active in the hydrogenation of polystyrene-b-polybutadiene-b-polystyrene (SBS) block copolymer. The catalytic efficiency was determined by monitoring the extent of saturation of bauble bounds on the polybutadiene segment of the copolymer using FTIR and ^1HNMR spectroscopy. The effects of H_2 pressure and the ratio of a-butyl-lithium to cobaltocene on the catalytic efficiency were investigated. Data from the UV spectroscopy of the catalyst system indicated that one of the Cp ligand in the original CP_2CO was substituted by the butyl group forming a CpCoBu as the major catalytic species. Other metallccenes, such as bis(ŋ^5-cyclopentadienyl)nickel and bis(ŋ^5-cyclopentadieny1)titanium dichloride. and other reducing agents. such as phenyllithium and triethylalurninum, have also been evaluated for their catalytic efficiencies.

並列關鍵字

Hydrogenation ； Metallocene ； Bis(ŋ^5-cyclopentadienyl)cobalt ； Bis(ŋ^5-cyclopentadienyl) nickel ； Bis(ŋ^5-cyclopentadienyl)titanium dichloride ； n-Butyllithium ； Styrene ； Butadiene ； Block copolymer ； Cobaltocene