【作者】 吴光明；

【导师】 孙维林； 沈之荃；

【作者基本信息】 浙江大学 ， 高分子化学与物理， 2009， 博士

【摘要】 本文首次采用“一锅法”用硼氢化稀土原位还原羰基化合物，并将得到的还原中间体作为引发剂直接用于ε-己内酯（ε-CL）的开环聚合，发展了一种方便制备端基功能化的聚ε-己内酯（PCL）的合成方法；生成的PCL经NMR表征，证明羰基化合物被还原后直接进入到了聚合物的端基中；通过对还原中间体的原位NMR研究，提出了两种可能经历的机理。另外，还合成了其它含有多元氧，氮配体的稀土金属配合物，用于聚合方面的研究。它们包括：以四氢席夫碱为骨架的稀土Gd，Y等配合物；以甲基化四氢席夫碱为骨架的含氯Yb，Er，Y等配合物；以双酚2，2′-ethylidene-bis（4，6-di-tert-butylphenol）（EDBPH₂）为骨架的阴离子型稀土Y，Yb，Er等配合物；基于多面齐聚倍半硅氧烷（POSS）的金属配合物（POSS-Ln，Ln=La，Nd，Gd，Y，Dy）。在这些基于多齿氧，氮配体的稀土金属配合物中，四氢席夫碱的Gd配合物用于ε-CL的开环聚合，研究了不同条件对聚合的影响。研究发现，在[CL]：[Gd】=600，T=56℃，toluene：2 mL的条件下，得到的PCL的Mw=113000，分子量分布PDI=1．96。合成的甲基化四氢席夫碱稀土Yb，Er，Y等配合物中，基于乙二胺的Er，Yb四氢席夫碱配合物在NaBH₄存在下，可以引发ε-CL的开环聚合，制备得到的是与传统PCL不一样的PCL，聚合物链端均为羟基；得到的PCL的分子量分布落在1．32-1．53的范围内。以硼氢化稀土为原料，温和条件下合成了以双酚为骨架的稀土Y，Yb等配合物，并对当中的Y配合物进行了明确的IR，NMR，EA，单晶X衍射的表征；将Y的配合物用于ε-CL的开环聚合，研究了不同条件对聚合的影响。研究发现，在65℃下，聚合过程部分有活性特征，分子量与[CL]／[Y]及聚合时间均呈线性关系，而PDI保留在1．09-1．36这样一个较窄的范围。通过异丙氧基稀土与POSS醇解的方式，合成了POSS-Ln结构的金属配合物（Ln=La，Nd，Gd，Y，Dy），并通过IR，NMR，EA及X射线单晶衍射表征了当中POSS-Nd的结构；单晶结构分析表明，这是一个新奇的四聚体结构，以Cl^-为核心，四个POSS-Nd单元包围在Cl^-的周围；以TMSC1为氯源，AlEt₃为助催化剂，能够很好地引发异戊二烯的聚合。更多还原

【Abstract】 In this work, a novel one-pot strategy was developed for the synthesis ofend-capped poly（ε-caprolactone） s（PCLs）: The carbonyl-containing compounds（aldehyde and ketone） were first in-situ reduced by lanthanide borohydride, andthe afforded reduction intermediates were employed as initiators for thering-opening polymerization to give a variety of end-capped PCLs; The successfulincorporation of end groups into the polymer chain was confirmed by NMR; Twopossible reduction-initiation mechanisms were postulated by in-situ NMR method.Several rare-earth based complexes were also synthesized, which were employedas initiators or catalysts for the polymerization. They are: 1) tetrahydrosalenbackboned gadolinium and yttrium complexes; 2)methylated tetrahydrosalenbackboned ytterbium, erbium and yttrium complexes;3)EDBPH₂ backboned yttrium andytterbium anionic complexes;4)polyhedral oligomeric silsesquioxane based POSS-Lncomplexes（Ln=La, Nd, Gd, Y, Dy）。Tetrahydrosalen backboned gadolinium was used to initiate the ring-openingpolymerization ofε-caprolactone, it was found that in the condition: [CL]: [Gd]=600, T=56℃, toluene: 2 mL, PCL with Mw = 113000 and PDI = 1.96 was obtained.Methylated tetrahydrosalen backboned ytterbium and erbium complexes were usedto initiate the ring-opening polymerization ofε-CL in the presence of NaBH,,and interesting hydroxytelechelic PCLs were obtained, whereas the formation ofgel is overcome, which is different from the lanthanide borohydride initiatedsystem.2,2’ -Ethylidene-bis（4,6-di-tert-butylphenol） （EDBPH₂） backboned yttrium andytterbium complexes were prepared by the salt-metathesis between lanthanideborohydride and sodium salt of EDBPH₂, and the yttrium complex was fullycharacterized by IR, NMR, EA, X-ray single-crystal methods. Polymerization resultsreveal that the ring-opening polymerization ofε-CL initiated by yttriumcomplex performed with some living characteristics: The linear relationshipsbetween the molecular weight and [CL]/[Y] or polymerization time were found, whereas the PDI kept in a narrow range （1.09-1.36）;Polyhedral oligomeric silsesquioxane based complexes（POSS-Ln, Ln=La, Nd, Gd, Y,Dy） were prepared through the alcoholysis between the POSS and lanthanideisoproxide, and the molecular structure of POSS-Nd was fully established by IR,NMR, EA and X-ray diffraction. The result reveals a new tetrameric structure. TheNd-O-Si bonding interactions can be used to mimic the silica-supported rare-earthcatalysts. Therefore, the POSS-Nd was employed as precursor for the polymerizationof isoprene, and polyisoprene with 93% cis-1, 4 selectivity was obtained.更多还原