CAS OpenIR
离子液体高效催化合成异山梨醇型聚碳酸酯
马聪凯
Subtype硕士
Thesis Advisor成卫国
2018-07
Degree Grantor中国科学院研究生院
Degree Name硕士
Degree Discipline化学工程
Keyword聚碳酸酯,异山梨醇,双功能离子液体,氢键,复配
Abstract

聚碳酸酯(PC)具有优良的性能,是应用最广泛的工程塑料之一。而作为新兴的绿色介质,离子液体具有结构和功能可调性,在催化领域应用前景广阔。针对目前PC合成需使用剧毒光气及大量有机溶剂、聚合单体双酚A (BPA) 会导致内分泌失调并危害人类健康、催化剂污染环境等问题,本文采用以异山梨醇与碳酸二苯酯为聚合单体的非光气熔融酯交换法,开发了两个催化体系:咪唑类离子液体催化体系和季铵类/金属催化剂复配体系,主要研究内容及成果如下:(1)成功合成了一系列绿色低毒的1-丁基-3-甲基咪唑类离子液体,催化合成异山梨醇型聚碳酸酯(PIC)。通过改变离子液体阴离子的结构,可以有效调节PIC的分子量和玻璃转化温度。在最优的反应条件下,[Bmim][CH3CHOHCOO]催化合成的PIC分子量(Mn)达到61,700 g/mol,产率达到99 %,玻璃转化温度(Tg)可达174 °C。结果表明离子液体阴离子的电负性越强或者氢键形成能力越强,则催化效果越好。此外,根据实验和核磁结果,提出了[Bmim][CH3CHOHCOO]可通过静电作用和形成氢键高效催化该聚合反应的阴阳离子协同催化机理。(2)为改善PIC的柔韧性,以[Bmim][CH3CHOHCOO]为催化剂,通过引入脂肪族二醇成功合成了四种脂肪族二醇/异山梨醇共聚型聚碳酸酯(PAICs)。采用核磁表征了PAICs的组成和结构,并借助DSC, TGA 和 DMA 等手段测试其性能。结果表明PIC和分子链中引入环状结构二醇的共聚物比其他引入直链型二醇合成的共聚物的热稳定好,并且PAICs的加工性能优于PIC。(3)开发了季铵类离子液体/金属催化剂复配体系,其中催化效果最佳的为[TEA][CH3COO] / LiAcac,其产物PIC的分子量可达到40,100 g/mol,产率95 %,PDI为1.60,Tg为171 °C。该体系也能够高效催化合成PAICs。所有共聚物中,1,4-丁二醇/异山梨醇共聚型聚碳酸酯(PBIC)的Mn最高,可达到93,800 g/mol,收率可达98 %。通过NMR、DSC、TGA等确定了产物结构并测试了其玻璃转化温度和热稳定性。;Polycarbonate (PC) is one of the most versatile engineering plastics due to its attractive properties. As the novel green media, ionic liquids (ILs) have shown great potential in catalysis owing to their tunable structures and properties. To address the problems of the usage of highly toxic phosgene, huge amount of organic solvent, endocrine-disrupting and health-threatening bisphenol-A (BPA) and environmentally unfriendly catalysts, two catalyst systems for the synthesis of poly(isosorbide carbonate) (PIC) from isosorbide and diphenyl carbonate by melt polycondensation method were developed: imidazolium inoic liquids and quaternary ammonium ionic liquids/metal compound catalysts. The main contents and results are as follows:(1) A series of green and low toxic 1-butyl-3-methyl-imidazolium based inoic liquids (ILs) were successfully prepared as catalysts to synthesize PIC. By modifying the structures of ILs’ anions, the molecular weight and glass transition temperature (Tg) of PIC were effectively tailored. PIC with an exteremly high number-average molecular weight (Mn) of 61,700 g/mol, yield of 99 % and glass transition temperature of 174 °C could be obtained catalyzed by bifunctional [Bmim][CH3CHOHCOO] under the optimized reaction conditions. The anions with stronger electronegativity and hydrogen bond formation ability, were found to be more efficient. Additionally, based on the experimental results and 1H NMR spectra, a possible mechanism of cooperative nucleophilic–electrophilic activation through electrostatic interactions and hydrogen bond formation by [Bmim][CH3CHOHCOO] was proposed.(2) Four poly(aliphatic diol-co-isosorbide carbonate)s (PAICs) were also prepared by incorporating with aliphatic diols catalyzed by [Bmim][CH3CHOHCOO] to modify the flexibility of PIC. The microstructure and comonomer composition were characterized by 1H NMR and 13C NMR. The properties of PIC and PAICs were determined by DSC, TGA and DMA. The results showed that the thermal stability of PIC and PAICs incorporated by cycloaliphatic diols was better than PAICs incorporated by linear diols and the processibility of PAICs were much better than PIC.(3) Besides, the quaternary ammonium ionic liquids/metal compound catalysts were developed, among which [TEA][CH3COO] / LiAcac showed the best catalytic performance. The corresponding Mn of PIC could reach up to 40,100 g/mol with a yield of 95 %, PDI of 1.60 and Tg of 171 °C. This compound catalyst could also efficiently catalyze the synthesis of PAICs. Among all of the copolyers, poly(1,4-butanediol diol-co-isosorbide carbonate)s (PBIC) possessed the highest Mn of 93,800 g/mol with a yield of 98 %. The structure, glass transition temperature and thermal stability of PAICs were determined by NMR, DSC and TGA. 

Language中文
Document Type学位论文
Identifierhttp://ir.ipe.ac.cn/handle/122111/26873
Collection中国科学院过程工程研究所
研究所(批量导入)
Recommended Citation
GB/T 7714
马聪凯. 离子液体高效催化合成异山梨醇型聚碳酸酯[D]. 中国科学院研究生院,2018.
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