铁系催化剂催化降冰片烯与丙烯酸甲酯共聚合

研究了Fe(acac)3-Al(i-Bu)3(acac=乙酰丙酮)催化降冰片烯(NB)与丙烯酸甲酯(MA)共聚反应条件影响、第三组份影响及催化剂铁铝比影响.并用核磁共振、红外光谱和元素分析方法研究了共聚物的组成,用热分析方法研究了共聚物的分解温度,并用电镜分析了共聚物的膜结构.结果表明,铁系催化剂在温和的反应条件下有较好的催化性能,并可获得能够形成有序多孔膜的共聚物.

COPOLYMERIZATION OF NORBORNENE AND METHYL ACRYLATE CATALYZED BY Fe(acac)3-Al(i-Bu)3

The copolymerization of norbornene (NB) with methyl acrylate (MA) in the presence of iron (Ⅲ) acetylacetonate Fe(acac)_3] associated with a triisobutylaluminum Al(i-Bu)_3] catalyst system was investigated.The polymerization was carried out under dry nitrogen in toluene in a glass flask equipped with a rubber septum.For preparing the catalyst system Fe(acac)_3 was first dissolved in the reaction solvent,and Al(i-Bu)_3 was then added.The monomers were first dissolved in the reaction solvent,and the catalyst was introduced to initiate the polymerization.After a given reaction time,the polymerization mixture was poured into a large amount of methanol containing a few percent of hydrochloric acid to precipitate the polymer.The liquid phase was filtered,and the recovered polymer was dried in vacuo.The characteristics of copolymerization of norbornene and methyl acrylate by Fe(acac)_3-Al(i-Bu)_3 were studied.The copolymers were characterized by FTIR, ~ 13 C-NMR,GPC and elementary analysis.Copolymers with NB content of 12.3 mol%,19.5 mol% and 26.0 mol%,respectively were prepared.The molecular weight of the copolymers was in the range of 0.52×10~5～1.05×10~5,and its distribution index M_w/M_n was in the range of 2.25～2.67. They both decreased with increasing the molar ratio of NB/MA.The copolymerization can be performed in the solvents such as aromatic hydrocarbons.The third composition could exert influence on the copolymerization.The yield of copolymers with a third composition like carbon tetrachloride or 1,4-dioxane and triphenylphosphine was higher than that of copolymers without the third composition.However,the addition of 1,10-phenanthroline or 8-hydroxy quinoline and α,α′-dipyridine decreased the yield.The copolymerization could be obtained at room temperatures,however,increasing reaction temperature caused an increase of the copolymer yield.The yield of copolymer was also changed with the change of Al/Fe molar ratio,and the suitable Al/Fe molar ratio was 25. The copolymer can form porous membrane on cover glass automatically with pore size of 7～15 μm during evaporation of THF from the copolymer solution at room temperature.