基于稀土金属催化剂的烯烃选择性聚合研究
文献类型：学位论文
| 作者 | 姚昌广 |
| 学位类别 | 博士 |
| 答辩日期 | 2015-05 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 中国科学院长春应用化学研究所 |
| 导师 | 崔冬梅 |
| 关键词 | 脒基(芴基)官能化氮杂环卡宾 稀土金属配合物 功能化单体 选择性 共聚 |
| 中文摘要 | 本论文通过合成和选用一系列适当的稀土金属催化剂，实现了对传统烯烃单体和合成烯烃单体的选择性聚合及共聚合。具体工作内容如下： (1) 合成了一系列芴基官能化的氮杂环卡宾稀土金属双烷基配合物(Flu-NHC)Ln(CH2SiMe3)2 (Flu-NHC = C13H8CH2CH2(NCHCHN(C6H2Me3-2,4,6)C), Ln = Sc, Er, Dy)，并对中心金属为Er和Dy的配合物进行了单晶结构表征。在40 oC和乙烯压力为1atm时，中心金属为Sc的配合物在等摩尔量的有机硼盐[Ph3C][B(C6F5)4]和20当量的AliBu3的活化作用下能够催化乙烯/α-烯烃(1-己烯，1-辛烯)共聚，活性最高分别可达4120和3640 kg?molSc–1?h–1?atm–1，共聚物中1-己烯和1-辛烯插入率分别可达20.2%和38.7%。但具有类似结构的Er和Dy的配合物却不能引发乙烯均聚或者乙烯/α-烯烃共聚。 (2) 合成了脒基氮杂环卡宾镥双烷基配合物(Am-NHC)Lu(CH2SiMe3)2 (Am-NHC = 2,6-iPrC6H3N=C(C6H5)NCH2CH2(NCHCHN(C6H2Me3-2,4,6)C)，并对其进行了核磁共振和X-射线单晶结构表征。在有机硼盐的活化作用下，该配合物可以催化异戊二烯高3,4-选择性活性聚合，选择性最高可达99.3%。该体系的3,4-选择性几乎不受温度、单体浓度、溶剂和硼盐种类的影响。同时，二元催化体系(Am-NHC)Lu(CH2SiMe3)2/[Ph3C][B(C6F5)4]还能催化己内酯均聚和与异戊二烯共聚，通过序列加料，可以获得3,4-异戊二烯-己内酯两嵌段共聚物。 (3) 通过Wittig反应，合成了1-位取代的丁二烯单体：(E)-1-(4-甲基苯基)-1, 3-丁二烯(E-1-MPBD)，在三组分体系(Flu-NHC)Lu(CH2SiMe3)2/[Ph3C][B(C6F5)4] /AliBu3的催化作用下，可以获得高间规(rrrr > 99%)高3,4-选择性(> 99%)的反式聚合物P(1-MPBD)。为了研究聚合物的高间规选择性，还合成了具有高3,4-含量(90.9%)、低间规度(rrrr = 49.3%)的模型化合物，通过对比二者的核磁谱图，证实了前者的高区域和立体选择性。此外，高间规聚合物P(1-MPBD)通过氢化反应获得了高间规选择性的聚(4-甲基苯基)-1-丁烯。 (4) 合成了一系列2-位芳基取代的丁二烯单体：2-苯基-1, 3-丁二烯(2-PB)、2-(4-甲基苯基)-1, 3-丁二烯(2-MPB)、2-(4-甲氧基苯基)-1, 3-丁二烯(2-MOPB)、2-(4-氟苯基)-1, 3-丁二烯(2-FPB)。其中，2-PB在(Am-NHC)Lu(CH2SiMe3)2/[Ph3C][B(C6F5)4]的催化下可以实现高3,4-选择性活性聚合，3,4-选择性最高可达96.7 %。选用β-双亚胺配体螯合的钇双烷基配合物(BDI)Y(CH2SiMe3)2(THF) (BDI: CH3C=N(C6H3-2,6-Me2)CHCNH(C6H3-2,6-Me2)CH3)作为催化剂前体，在等摩尔量的[Ph3C][B(C6F5)4]和10当量的AliBu3作用下，上述4种单体均能实现顺-1,4选择性聚合，其中2-MOPB和2-FPB的选择性都大于98%，而2-PB和2-MPB的顺-1,4选择性都在80-90%之间。同时，该三组分催化体系还能催化4种单体分别与异戊二烯共聚，所得共聚物中各自的顺式选择性都能够与均聚物保持一致。 (5) 选用噻吩稠合的取代环戊二烯基钪双烷基配合物作为催化剂前体{2,5-Me2-3-Ph-6H-cyclopenta[b]thiophenyl)Sc(CH2SiMe3)2(THF)}，在[Ph3C][B(C6F5)4]和AliBu3的作用下，它能催化苯乙烯高间规选择性聚合(rrrr > 99%)；而对于合成的功能化苯乙烯单体——4-烯丙氧基苯乙烯(AOSt)，该三元体系虽然能高活性地催化其聚合，但所得聚合物PAOSt却没有立体选择性，同时苯乙烯和AOSt的共聚物也没有立体选择性。为了探索功能化单体均聚和共聚失去选择性的原因，我们合成了两种单体——4-丙氧基苯乙烯(POSt)和4-(3-丁烯基)-苯乙烯(BTSt)，发现前者在与苯乙烯共聚时能够保持间规选择性，而后者与苯乙烯的共聚物同样没有立体选择，证明AOSt均聚或者共聚失去立体选择性的原因是由于单体中的烯丙基双键造成的。同时，通过Thiol-ene反应，合成了接枝共聚物PS-g-PEG。 |
| 英文摘要 | A series of rare-earth metal complexes has been synthesized and used to (co)polymerize the commercial or synthetic monomers with special selectivities. The details are listed as follows. (1) Rare-earth metal bis(alkyl) complexes (Flu-NHC)Ln(CH2SiMe3)2 (Ln = Dy, Er, Sc) attached by fluorenyl modified N-heterocyclic carbene ligands ((Flu H–NHC–H)Br) (Flu-NHC = C13H8CH2CH2(NCHCHN(C6H2Me3-2,4,6)C) were synthesized and characterized by X-ray diffraction analysis. Under mild conditions (40 oC and normal ethylene pressure), the scandium precursor, upon activation of AliBu3 and [Ph3C][B(C6F5)4], showed high activity (4120 or 3640 kg?molSc–1?h–1?atm–1) for the copolymerization of ethylene and 1-hexene or 1-octene with moderate 1-hexene insertion ratio (20.2%) and high 1-octene incorporation ratio (38.7%). Unfortunately, the Dy and Er analogous complexes were inert towards ethylene polymerization or the copolymerization of ethylene with α-olefins. (2) Amidino modified N-heterocyclic carbene ligated lutetium bis(alkyl) complex, (Am-NHC)Lu(CH2SiMe3)2 (Am-NHC = 2,6-iPrC6H3N=C(C6H5)NCH2CH2(NCHCHN(C6H2Me3-2,4,6)C), was synthesized and characterized by NMR spectrum and X-ray diffraction analysis. Under the activation of an organoborate, complex (Am-NHC)Lu(CH2SiMe3)2 exhibited distinguished catalytic performances for the polymerization of isoprene with respect of high activity, 3,4-regioselectivity (99.3%) and livingness mode. This binary system seemed not to be affected obviously by the polymerization temperature (0–80 oC), solvents, monomer-to-initiator ratios (500–5000) and the type of organoborates. In addition, the living lutetium-polyisoprene active species could further initiate the ring-opening polymerization of ε-caprolactone to give selectively the poly(3,4-isoprene)-b-polycaprolactone block copolymers with controllable molecular weight and narrow polydispersity. (3) (E)-1-(4-Methylphenyl)-1,3-butadiene (E-1-MPBD) synthesized via the ‘Wittig-type’ reaction was polymerized with the ternary catalytic system (Flu-NHC)Lu(CH2SiMe3)2/AliBu3/[Ph3C][B(C6F5)4] to afford a new product containing exclusively trans-3,4 (> 99%) units with perfect syndiotacticity (rrrr > 99%). The regio-3,4 tacticity was proved by the IR and NMR (1H and 13C) spectroscopic analyses, while the 3,4-stereotacticity was confirmed by a model polymer with lower regularity (3,4 = 90.9%, rrrr = 49.3%) prepared by the binary catalytic system (Am-NHC)Lu(CH2SiMe3)2/[Ph3C][B(C6F5)4]. Moreover, hydrogenating the resulting polymer gave the high syndiotactic poly(4-methylphenyl-1-butene) that cannot be achieved by any other manner at the present stage. (4) A series of 2-aryl-1,3-butadienes including 2-phenyl-1,3-butadiene (2-PB), 2-(4-methylphenyl)-1,3-butadiene(2-MPB), 2-(4-methoxyphenyl)-1,3-butadiene(2-MOPB) and 2-(4-fluorophenyl)-1,3-butadiene(2-FPB) was synthesized and polymerized with various rare-earth metal precursors. Under the catalysis of the binary system (Am-NHC)Lu(CH2SiMe3)2/[Ph3C][B(C6F5)4], the monomer 2-PB showed highly 3,4-selectivity(96.7%) and livingness mode. And all of the four monomers showed high cis-1,4 selectivity polymerized with the ternary system BDI-Y/AliBu3/[Ph3C][B(C6F5)4] (BDI-Y={CH3C=N(C6H3-2,6-Me2)CHCNH(C6H3-2,6-Me2)CH3}Y(CH2SiMe3)2(THF) ) The selectivities of monomers 2-MOPB and 2-FPB are more than 98% but the other two monomers are between 80% and 90%. Additionally, this ternary catalytic system could copolymerize each substituted butadiene and isoprene with highly cis-1,4 selectivities. (5) Thiophene-fused methylcyclopentadienyl scandium bis(alkyl) complex, upon the activation of [Ph3C][B(C6F5)4] and AliBu3, exhibited highly activity for styrene (St) polymerization with highly syndioselectivity (rrrr > 99%) and 4-allyloxystyrene (AOSt) polymerization with atactic-selectivity. Other two monomers 4-propoxystyrene (POSt) and 4-(3-butenyl)styrene(BTSt) were synthesized and used for copolymerization with styrene. The obtained copolymer P(St-co-BTSt) was still atactic but the copolymer P(St-co-POSt) displayed syndioselectivity. Moreover, the graft copolymers PS-g-PEG had been obtained via thiol-ene coupling reaction between the alkene-functional groups along the side chains of the copolymer P(St-co-AOSt) and the sulfydryl in the terminal of PEG. |
| 语种 | 中文 |
| 公开日期 | 2016-05-03 |
| 源URL | [http://ir.ciac.jl.cn/handle/322003/64490]  |
| 专题 | 长春应用化学研究所_长春应用化学研究所知识产出_学位论文 |
| 推荐引用方式 GB/T 7714 | 姚昌广. 基于稀土金属催化剂的烯烃选择性聚合研究[D]. 中国科学院长春应用化学研究所. 中国科学院研究生院. 2015. |
入库方式： OAI收割
来源：长春应用化学研究所
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