【作者】 李琳；

【导师】 李光兴；

【作者基本信息】 华中科技大学 ， 材料物理与化学， 2005， 博士

【摘要】 随着高分子材料的发展和聚烯烃的研究不断深入,聚烯烃功能化研究尤为令人瞩目。丰富而廉价的一氧化碳与烯烃共聚是制造功能性聚烯烃的一种有效途径。CO 和一种或多种含双键的不饱和单体进行交替共聚反应可以得到产物—聚酮高分子,其合成、性质与应用是基础研究与工业开发的热点, 而寻找高效、廉价的催化体系是聚酮研究中一项十分重要的工作。据报道,Pd（OAc）₂/bipy/CF₃SO₃H 体系对于苯乙烯与CO 的共聚反应具有较高的催化活性,但是当用PdCl₂替代Pd（OAc）₂后,相应的催化体系PdCl₂/bipy/CF₃SO₃H 的活性很低。论文研究了在三氟甲基磺酸盐（M（CF₃SO₃）n）的助催化作用下,首次将PdCl₂ 作为催化前体用于苯乙烯与CO 共聚制备聚酮（PK）的反应体系中, 并取得了较好的催化效果。在PdCl2为1×10^-4mol, 2,2’-联吡啶（bipy）为5×10^-4mol, Cu（CF₃SO₃）₂为2×10^-4mol, 对苯醌（BQ）为3×10^-3mol, 苯乙烯为10ml, 甲醇为4ml,温度为65℃,CO 压力为3.0MPa的条件下,苯乙烯/CO 共聚活性高达1.80×10⁴ gPK/（molPd·h）,共聚产物重均分子量（Mw）为4.60 ×10³g/mol 。加入一定量的溶剂邻氯苯酚后可使活性进一步提高到2.00×104gPK/（molPd·h）,共聚物的重均分子量同时提高至1.86×10⁴g/mol。本文从催化活性和共聚产物分子量等方面系统讨论了氯化钯/三氟甲基磺酸盐/含氮双齿配体催化体系中各活性组份及反应条件对苯乙烯/CO 共聚反应的影响,尤其对M（CF₃SO₃）n 良好的助催化效果及其机理进行了详细地讨论。利用量子化学理论初步计算所得结果, 分析了5-硝基-邻菲咯啉(NO_2-phen), 5-氨基-邻菲咯啉(NH_2-phen), 邻菲咯啉（phen）和bipy 等分子的键长, 键角和电子云密度, 并针对这几种含氮配体在苯乙烯与CO共聚反应中不同的助催化性能进行了合理解释。采用核磁共振(¹HNMR、¹³CNMR)、傅立叶红外光谱（FT-IR）、元素分析（EA）、凝胶渗透色谱（GPC）、粉末广角X-衍射（XRD）、热重分析（TGA）和差热扫描（DSC）等检测手段对苯乙烯/CO 共聚产物（STCO）进行了详细的结构表征,证实了产物为严格交替共聚、结晶度较高的聚酮。结合前人机理研究成果对氯化钯/三氟甲基磺酸盐/含氮双齿配体新型催化体系下苯乙烯/CO 共聚反应机理进行了初步探讨。本文还进一步研究了氯化钯/三氟甲基磺酸盐/含氮双齿配体催化体系下张力环烯烃如双环戊二烯（DCPD）和冰片烯（NBE）与CO的共聚反应,发现此催化体系对于DCPD/CO更多还原

【Abstract】 Copolymerization of carbon monoxide and olefins is an effective approach to prepare functional macromolecules, especially polyketones and polyalkenes. Polyketone, obtained by alternating copolymerization of carbon monoxide and olefinically unsaturated monomers such as styrene, is a class of low-cost innovative thermoplastics. The synthesis, properties and applications of polyketones are still the objects of intense fundamental and applied research. It was reported that the Pd（OAc）₂/bipy/CF₃SO₃H catalytic system had a very high catalytic activity on the copolymerization of styrene and CO, but if PdCl₂ was used instead of Pd（OAc）₂, the corresponding catalytic system, PdCl₂/bipy/CF₃SO₃H, had very low activity. In this paper, it is found that PdCl₂ has excellent catalytic activity on the copolymerization of styrene and CO as catalytic precursor under the prominent co-catalytic effects of M（CF₃SO₃）n. At the reaction temperature of 65℃and the pressure of CO 3.0MPa with PdCl2 1×10^-4mol, bipy 5×10^-4mol, Cu（CF₃SO₃）₂ 2×10^-4mol, BQ 3×10^-3mol, styrene 10ml, methanol 4ml,the catalytic activity was 1.80×10⁴gPK/（molPd·h） in the copolymerization of styrene with CO and the Mw of the styrene/CO copolymer （STCO） was 4.60×10³g/mol. Adding solvent o-chloride-phenol into the catalytic system, the corresponding activity could be increased to 2.00×10⁴gPK/（molPd·h） and the Mw of STCO also increased to 1.86×10⁴g/mol. The effects of catalytic components and reaction conditions on the copolymerization of styrene/CO have been studied in detail for the catalytic system of PdCl₂/M（CF₃SO₃）n/N-N ligands. The prominent co-catalytic effects of M（CF₃SO₃）n and the mechanism were especially discussed. Quantum chemistry was used to calculate the bond-length, bond-angle and density of electron cloud of NO_2-phen, NH_2-phen, phen and bipy, and the different catalytic activities of these four N-N bidentate ligands in the copolymerization of styrene with CO were explained by the calculation results. The structure and properties of STCO were characterized by ¹HNMR, ¹³CNMR, FT-IR, EA, GPC, XRD, TGA and DSC, and it is found that the product polyketone is the linear alternating copolymer of styrene and CO. The catalytic mechanism of the copolymerization of styrene and CO catalyzed by PdCl₂/M（CF₃SO₃）n/bipy was also discussed. In addition, it is shown that the catalytic system of PdCl2/M（CF3SO3）n/N-N ligands also has excellent catalytic effects on the copolymerization of dicyclopentadiene/CO and norbornene/CO. Under certain reaction conditions, the catalytic activity of DCPD/CO and NBE/CO reached to 5.73×104gP/（molPd·h） and 8.20×104 gP/（molPd·h）, respectively. The cooligomers of strained olefins and CO were analyzed using various techniques such as FT-IR, 1HNMR, 13CNMR, TGA and XRD. The results indicated that the cooligomer of DCPD/CO was a polyspiroketal with different end groups. Compared with the copolymerization of styrene/CO, the activities of strained olefins with CO were much higher and the degree of crystallinity was not high due to the tension of the ring. The catalytic mechanisms of the copolymerization of DCPD/CO and NBE/CO catalyzed by PdCl2/M（CF3SO3）n/bipy were also investigated on the basis of literatures. Homogeneous catalytic systems have suffered from disadvantages such as difficult separation of the products and corrosive effect of the catalyst on the reactor. The supported catalyst will offer an alternative way to remedy the disadvantages of homogeneous catalyst. In this paper, Pd（OAc）2 and PdCl2 have been successfully immobilized on NH2-phen modified polystyrene. The structures of the resultant catalysts were characterized with various techniques such as FT-IR, XPS, EA, TGA, AAS and FESEM. The PS-phen/Pd（Ⅱ） catalysts have certain catalytic activities for the copolymerization of styrene and CO, and the catalysts could be separated easily and be reused for several times. After recycling for three times, the catalytic activity of PS-phen/Pd（OAc）2 was decreased from 1.02 ×104gPK/（molPd·h） to 570gPK/（molPd·h） and that of PS-phen/PdCl2 was decreased from 5.50×103gPK/（molPd·h） to 97.4gPK/（molPd·h） under the reaction conditions of CO 3.0MPa and 65℃. It was noteworthy that the Mw of STCO catalyzed by PS-phen/Pd（Ⅱ） were reasonably high, reaching to 6.86×103g/mol and 7.33×103g/mol, respectively. In order to discuss the mechanism of the supported catalyst, for the fresh supported catalyst PS-phen/Pd（Ⅱ） and reused catalyst after reaction, EA, AAS, FT-IR, XPS, TGA and FESEM were used to analyze the change of catalysts and the reason of decreasing of catalytic activity. It is found that the loss of Pd and N is the main factor to result in the decreasing of catalytic activity.In conclusion, the copolymerization of styrene, dicyclopentadiene and norbornene with carbon monoxide has been studied in this paper, and the novel catalytic system of PdCl2/M（CF3SO3）n/N-N ligands is found to have excellent effects on the copolymerization. The catalytic mechanism of the copolymerization catalyzed by this new system was discussed in detail. The study on this new catalytic system provides a valuable foundation for exploiting the system of polyketone with great perspective of application.更多还原