钛/铝配合物催化剂下二氧化碳共聚物的合成
文献类型：学位论文
| 作者 | 王勇 |
| 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 | 王佛松 ; 王献红 |
| 关键词 | 二氧化碳 Salen钛配合物 卟啉铝配合物 双官能催化剂 二氧化碳共聚物 |
| 中文摘要 | 钛/铝配合物催化剂下二氧化碳共聚物的合成 摘要 学生：王勇（高分子化学与物理） 导师：王佛松 院士 王献红 研究员 二氧化碳储量丰富，价格低廉，是一种理想的C1资源，以二氧化碳为原料合成大宗小分子化合物已有很多工业化案例。二氧化碳和环氧化合物的共聚反应是少有的能够净消耗二氧化碳的反应过程，同时能够生成生物可降解塑料，有望成为传统的非降解聚烯烃塑料的替代品，解决日益严重的白色污染问题。因此二氧化碳和环氧化物共聚也具有很好的工业化潜力。目前钴系配合物(Salen)Co(III)X为代表的催化体系已经显示了很高的催化活性和产物选择性，但是Co是一种有毒金属，在各种行业标准被被严格限制使用，尤其是作为生物降解塑料使用必须满足可堆肥的前提，但Co系催化剂在产品中可能的残余是该催化体系的一个瓶颈问题，影响了其工业化应用。但是从学术研究的角度来分析，钴系催化剂的设计理念和催化机理的研究为新催化体系的研发具有很大的借鉴价值。本文正是以Co系催化剂的设计理念为基础，以环境友好型金属为催化中心代替钴，发展钛系催化剂和双官能卟啉铝催化剂，探索其对二氧化碳和环氧化合物的共聚反应的催化行为。所取得的主要结果如下： 1．根据(Salen)Co(III)X体系催化二氧化碳和环氧化合物共聚的机理，在Salen配体的衍生物Salalen上引入活泼氢，用强碱拔去活泼氢使Salalen能够提供-3价配位环境，合成了与(Salen)Co(III)X结构类似的四价钛配合物 (Salalen)Ti(IV)Cl。在季铵盐类助催化剂[PPN]Cl作用下，能够催化二氧化碳和环氧环己烷（CHO）共聚，得到完全交替结构的共聚物，同时显示出活性聚合的特征。但是作为钛的最高氧化态，四价钛形成的Ti-O键极性较弱，阻碍了二氧化碳和环氧环己烷共聚合的链增长反应，在70oC和4.0MPa下反应的TOF仅为24h-1，且反应温度升高会导致大量环状碳酸酯副产物的生成 2．为增强Ti-O键的极性，合成了三价钛为中心金属的配合物(Salen)Ti(III)Cl，在70 oC和4.0 MPa下催化二氧化碳和环氧环己烷的共聚反应， TOF达到84h-1。同时发现 (Salen)Ti(III)Cl有良好的热稳定性，高温下依然保持高的产物选择性，在120oC和4.0MPa下的TOF高达577h-1，且没有环状碳酸酯副产物生成，并且聚合物为完全交替结构。 3．以季铵盐双官能团卟啉铝催化体系为基础，将大位阻有机碱1,5,7-三氮杂双环[4,4,0-癸-5-烯]（TBD）引入到卟啉铝，合成了有机碱双官能团卟啉铝配合物，用于催化二氧化碳和环氧丙烷（PO）的共聚反应。与双官能团季铵盐卟啉铝催化剂相比，有机碱双官能团卟啉铝铝催化体系有更高的催化活性和产物选择性。在90oC和3.0MPa下TOF高达1400h-1，聚合物的选择性89%。 4．引入不对称卟啉配体，合成了官能度为1，2，4的双官能团卟啉铝配合物，分别研究了官能度对有机碱双官能团卟啉铝体系和季铵盐双官能团卟啉铝体系催化性能的影响。发现随着官能度增加，有机碱双官能团卟啉铝催化活性升高，产物选择性保持不变，而季铵盐双官能团卟啉铝催化活性升高，产物选择性逐渐降低。 |
| 英文摘要 | Copolymerization of CO2 and Epoxides under Titanium or Aluminum Complex Catalyst Abstract Yong Wang (Polymer Chemistry and Physics) Directed by: Professor Fosong Wang Professor Xianhong Wang The utilization of CO2 as C1 resource has attracted extensive attention because it is inexpensive, rich and renewable carbon resource. Selective transformation of CO2 into biodegradable polycarbonates by alternating copolymerization with epoxides is an important green polymerization process, having great potentiality in industrialization. Such a reaction not only provides a net CO2 consuming process benefitting the environment, but also produces biodegradable polymers as possible solution to the white pollution problem due to the overuse of non-biodegradable. Among all the catalyst system ever developed till now, (Salen)Co(III)X displayed most ideal features like high catalytic activity and excellent polymer selectivity, as well as producing polymer with strict alternating structure and high molecular weight, however, the toxic feature of cobalt keeps it away from industry application, since the cobalt residue in biodegradable plastics is not acceptable, especially for the soil compostable requirement in which the toxic cobalt is strictly limited. In this thesis, environment-friendly catalyst based on titanium and aluminum complexes were designed and synthesized, inspired by the mechanistic understanding and designing strategy in (Salen)Co(III)X system. The main results are presented as follows. 1. Based on the mechanism understanding of (Salen)Co(III)X system, tetravalent titanium complexes were prepared from salen ligand (salen-H2= N, N-bis(3, 5-di-tert-butylsalicylidene)-1,2-benzenediamine) and its half saturated form salalen, and used as catalysts in combination with bis(triphenylphosphino)iminium chloride ([PPN]Cl) for coupling reaction of CO2 and cyclohexene oxide (CHO). Salen titanium complex (Salen)Ti(IV)Cl2 showed moderate activity producing unique cis-isomer of cyclic carbonate with high conversion up to 100% in 8h, however, it could not catalyze the copolymerization reaction. While salalen titanium complex (Salalen)Ti(IV)Cl was effective for the copolymerization of CO2 and CHO, where only one chain grew on Ti during chain propagation reaction, yielding completely alternating copolymer with -OH and -Cl as terminal groups. 2. In order to strengthen the polarity of Ti-O bond to accelerate the rate of chain propagation reaction, trivalent titanium complex combining salen ligand (salen-H2=N,N-bis(3,5-di-tert-butylsalicylidene)-1,2-benzenediamine) was synthesized, and used as catalyst for copolymerization of CO2 and cyclohexene (CHO). In combination with onium salt [PPN]Cl, (Salen)Ti(III)Cl, trivalent titanium complex showed impressive activity and selectivity, yielding completely alternating copolymer without the formation of cyclohexene carbonate (CHC), with turnover frequency (TOF) of 557 h-1 at 120 oC, which was more than 10 times higher than that from (Salalen)Ti(IV)Cl, and approaching that from the toxic Cr complex. In addition to the biocompatibility of Ti, thermally robust character resulting from the reducibility of trivalent Ti was industry desirable. 3. Bifunctional aluminum prophyrin complex bearing steric Lewis base 1,5,7-Triazabicyclo[4.4.0]dec-5-ene (TBD) on the ligand framework was prepared, and used as catalyst for the copolymerization of CO2 and propylene oxide (PO). It displayed superior catalytic activity and selectivity compared to its quaternary ammonium salt analog, a TOF of 1,400 h-1 was achieved a t 90 oC under 3.0 MPa. 4. Asymmetric porphyrin ligand was designed, and bifunctional aluminum porphyrin with functionality of 1, 2 and 4 were synthesized. As for bifunctional aluminum porphyrin anchored with steric Lewis base, the catalytic activity increased with the increase of functionality, while the selectivity maintained almost the same, while the quaternary ammonium salts analogs showed |
| 语种 | 中文 |
| 公开日期 | 2016-05-03 |
| 源URL | [http://ir.ciac.jl.cn/handle/322003/64480]  |
| 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 | 王勇. 钛/铝配合物催化剂下二氧化碳共聚物的合成[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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