萜烯基环碳酸酯及其非异氰酸酯聚氨酯的制备与性能研究（摘要）

以萜烯基环氧树脂（TME）为原料,与CO2反应合成萜烯基环碳酸酯（TCC）,TCC分别与乙二胺、1,6-己二胺、三乙烯四胺、四乙烯五胺及异佛尔酮二胺反应制备线性非异氰酸酯聚氨酯（NIPU）,并以环氧树脂E-51改性制备杂化非异氰酸酯聚氨酯（HNIPU）。研究了萜烯基环碳酸酯与胺基化合物的交联反应活性、反应动力学特征以及环氧树脂改性对NIPU交联反应的影响,探讨了NIPU及HNIPU聚合物材料的形成过程与机理。相关为萜烯基NIPU替代传统PU应用于环境友好涂料领域提供良好的理论基础。     

烯烃与二氧化碳直接合成环碳酸酯的研究进展

二氧化碳(CO_2)是一种来源丰富、价廉易得的C1资源,将二氧化碳化学固定为环碳酸酯是最具工业应用前景的CO_2资源化利用途径之一。相比于环氧化物与CO_2反应制备环碳酸酯,以毒性小、价格低廉的烯烃为原料,通过环氧化、CO_2环加成反应一步制备环碳酸酯,由于反应路线简洁、原子经济性高,具有重要的工业应用价值。在此回顾了近年来烯烃与CO_2直接合成环碳酸酯的研究进展,着重介绍了不同种类的催化剂,主要包括离子液体、金属氧化物或盐、金属有机配合物、金属有机框架材料等催化剂,并对其未来发展方向进行了展望。     

多元环碳酸酯的合成与表征

以环氧树脂E-44为原料,在高温、高压、催化剂存在下使环氧基转化为五元环碳酸酯基,并通过FT-IR、1HNMR、元素分析、GPC等方法对环碳酸酯进行表征.详细讨论了催化剂的种类、反应温度、反应压力、反应时间等对环氧基转化率以及产物外观的影响.结果表明,当温度在100℃,二氧化碳压力在1.5 MPa,以四丁基溴化胺和溴化钾为催化剂,反应5 h,环氧基的转化率可达95%以上,而且产物外观较好.     

三羟甲基丙烷三缩水甘油醚环碳酸酯的合成及表征

采用CO2插入法合成了三羟甲基丙烷三缩水甘油醚环碳酸酯。通过对不同反应体系CO2消耗量的对比讨论了反应温度、压力和不同催化剂及用量对反应的影响,并以红外光谱、核磁共振谱进行表征。结果表明,三羟甲基丙烷三缩水甘油醚中的环氧基团生成了环碳酸酯基团,当以质量分数3%～4%四丁基溴化铵为催化剂,在120℃、2 MPa条件下反应时,合成的环碳酸酯反应转化程度较高。     

非异氰酸酯聚氨酯涂料的制备及性能研究

将2,3-环碳酸甘油酯甲基丙烯酸酯(PCMA)与丙烯酸酯类单体共聚生成的聚合物作为主要成膜物,以二乙烯三胺为固化剂,制备了非异氰酸酯聚氨酯涂膜(NIPU).通过门-IR对涂膜结构进行分析,证明了聚氨酯特殊基团氨基甲酸酯的合成;并通过对漆膜综合性能的研究,确定了共聚实验配方及固化合成NIPU的最佳工艺.配制的清漆漆膜综合性能优良,同时其制备过程中不以有毒、高湿敏性的异氰酸酯为原料,安全、环保.     

环氧环己烷与二氧化碳合成碳酸环己烯酯的化学反应动力学

引言由于CO2排放量的急剧增加,“温室效应”已成为当今世界性的难题,固定CO2并综合利用CO2的研究显得越来越重要。CO2和环氧化合物经过环加成反应制备环状碳酸酯的工艺路线,为固定和利用CO2提供了一条有效途径。环状碳酸酯不仅是一种性能优良的高沸点、高极性的有机溶剂,而且在     

端环碳酸酯基聚醚的合成

采用端环氧基聚醚与二氧化碳为原料,在高温、高压、催化剂的条件下,将环氧基转化为五元环碳酸酯基。讨论了催化剂类型、温度、压力对反应转化率的影响,并通过红外光谱、核磁共振氢谱等方法对端环碳酸酯基聚醚进行结构表征。结果表明,当采用十六烷基三甲基溴化铵为催化剂,温度为120℃,体系压力为2.5 MPa时,环氧基的转化率能够达到90%以上。     

由二氧化碳出发合成有机碳酸酯

对以二氧化碳为原料合成有机碳酸酯的环氧路线、酯交换和直接合成方法作了综合评述 ,认为直接合成是最佳的合成路线。碳酸酯的直接合成可在均相及多相催化体系中进行 ,负载金属、金属甲氧基化合物及碱均可作为催化剂。直接法研究的关键在于高性能催化剂的开发、由二氧化碳对金属 -氧键插入反应导致的催化循环的构筑及耦合反应的应用。     

碱催化二氧化碳和丙三醇合成丙三醇碳酸酯的研究

以不同的无机碱和有机碱作为催化剂,乙腈为溶剂,研究了二氧化碳和丙三醇合成丙三醇碳酸酯的反应.结果发现碱性增强有利于反应的进行,在所选用的无机碱或有机碱中,Cs2C03)和TBD分别显示了最高的催化活性.乙腈在反应过程中不仅作为溶剂同时还起到了脱水剂的作用,极大地提高了丙三醇的转化率和丙三醇碳酸酯的收率.     

CO2和CH3OH直接合成碳酸二甲酯催化剂研究进展

碳酸二甲酯是一种绿色的有机合成中间体,由CO2直接合成碳酸二甲酯备受关注。本文介绍了CO2和CH3OH直接合成碳酸二甲酯的各种催化剂,分析了催化剂的优缺点,探讨了催化反应的机理。同时介绍了合成碳酸二甲酯的新技术和新方法。最后指出了由CO2直接合成碳酸二甲酯的研究趋势。     

丙烯酸松香加成物与GMA酯化物的合成与表征

以丙烯酸松香加成物（RA）和甲基丙烯酸缩水甘油酯（GMA）为单体,三乙胺为催化剂,对苯二酚为阻聚剂,在有机溶剂甲苯中合成了RA与GMA酯化物（RAG）,采用单因素和正交试验对酯化反应进行优化。通过傅里叶变换红外光谱（FT-IR）、凝胶渗透色谱（GPC）、黏度计、核磁共振氢谱（¹H NMR）和热重（TG）对酯化物进行了分析与表征。结果表明,RA与GMA酯化物较优合成条件为n_GMA：n_RA=2：1,三乙胺用量为RA质量的0.5%,120℃下反应4 h,该条件下合成的酯化物为深黄棕色澄清液体,酯化率为99.5%,数均相对分子质量为547,重均相对分子质量为848,25℃下测得其质量分数51%甲苯溶液的黏度为10 mPa·s。FT-IR和¹H NMR分析表明成功合成了RA与GMA酯化物。TG分析表明酯化物热稳定性高于丙烯酸松香加成物。     

CO2甲烷化研究进展

CO_2是造成温室效应的主要气体,作为碳基能源使用的末端形态,CO_2也是种重要的基础碳源。因此,将CO_2转化为能源产品可以快速实现碳的循环,对环境与能源领域意义重大。介绍了CO_2的排放、回收以及资源化利用现状,从催化剂体系、反应机理、合成工艺以及工业化现状等方面系统地介绍了CO_2甲烷化的发展。针对H2供给对CO_2甲烷化应用的限制,分析了电解水制氢再与CO_2进行甲烷化反应的电制气(Pt G)技术的发展现状、工艺路线及其经济性,讨论了该技术在我国应用的可行性。提出随着CO_2捕集与新能源相关技术的发展,Pt G技术会更加成熟,将有望成为未来CO_2资源化利用的重要形式。     

CO2 absorption and regeneration of alkali metal-based solid sorbents

Potassium-based sorbents were prepared by impregnation with potassium carbonate on supports such as activated carbon (AC), TiO₂, Al₂O₃, MgO, SiO₂ and various zeolites. The CO₂ capture capacity and regeneration property were measured in the presence of H₂O in a fixed-bed reactor, during multiple cycles at various temperature conditions (CO₂ capture at 60 °C and regeneration at 130–400 °C). Sorbents such as K₂CO₃/AC, K₂CO₃/TiO₂, K₂CO₃/MgO, and K₂CO₃/Al₂O₃, which showed excellent CO₂ capture capacity, could be completely regenerated above 130, 130, 350, and 400 °C, respectively. The decrease in the CO₂ capture capacity of K₂CO₃/Al₂O₃ and K₂CO₃/MgO, after regeneration at temperatures of less than 200 °C, could be explained through the formation of KAl(CO₃)₂(OH)₂, K₂Mg(CO₃)₂, and K₂Mg(CO₃)₂·4(H₂O), which did not completely converted to the original K₂CO₃ phase. In the case of K₂CO₃/AC and K₂CO₃/TiO₂, a KHCO₃ crystal structure was formed during CO₂ absorption, unlike K₂CO₃/Al₂O₃ and K₂CO₃/MgO. This phase could be easily converted into the original phase during regeneration, even at a low temperature (130 °C). Therefore, the formation of the KHCO₃ crystal structure after CO₂ absorption is an important factor for regeneration, even at the low temperature. The nature of support plays an important role for CO₂ absorption and regeneration capacities. In particular, the K₂CO₃/TiO₂ sorbent showed excellent characteristics in CO₂ absorption and regeneration in that it satisfies the requirements of a large amount of CO₂ absorption (mg CO₂/g sorbent) and fast and complete regeneration at a low temperature condition (1 atm, 150 °C).     

碳酸钾-乙醇胺复合溶液吸收烟气中CO2的实验研究

分别以不同浓度的碳酸钾溶液及不同配比的碳酸钾—乙醇胺复合溶液作为吸收剂,以吸收速率和吸收量为指标,研究了吸收剂对烟气中CO2的吸收效果.结果表明,纯碳酸钾溶液吸收效果不佳,而掺入乙醇胺后的吸收效果显著改善,部分复合溶液的吸收效果甚至好于同浓度纯碳酸钾溶液与纯乙醇胺溶液的吸收效果之和,碳酸钾与乙醇胺在吸收过程中存在正交互作用.确定0.6 mol·L-1碳酸钾-0.4mol· L-1乙醇胺复合溶液为最佳的吸收剂,其饱和吸收量最大(0.185 mol)、再生温度最低(105℃)、再生率最高(98.8％).     

Supercritical CO2 dispersion of nano-clays and clay/polymer nanocomposites

Dispersed polymer/clay nanocomposites are of great interest because they can significantly improve the properties of existing polymeric materials. However, achieving a high level of clay dispersion has been a key challenge in the production of polymer/clay nanocomposites. In this paper, we explore a novel supercritical carbon dioxide (scCO₂) processing method that utilizes scCO₂ to disperse nano-clays. The structure and properties of the clays and the resultant nanocomposites are characterized using a combination of wide-angle X-ray diffraction (WAXD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and rheology. Significant dispersion was achieved with dry Cloisite 93A clay, whereas relatively poor dispersion was achieved with dry Cloisite Na⁺ (natural clay). The extent of clay dispersion appears to be dependent on the ‘CO₂-philicity’, which in turn appears to depend on the surface modifications and inter-gallery spacing. The presence of an acidic hydrogen on the surfactant in Cloisite 93A appears to play a strong role in its ‘CO₂-philicity’. The ability to delaminate dry clays is significant because it will likely increase the ability to produce dispersed clay/polymer nanocomposites via melt processing. In addition to delaminating dry clays, we demonstrate that CO₂-phobic Cloisite Na⁺ (natural clay) can be partially dispersed with scCO₂, using a CO₂-philic polymer, polydimethylsiloxane (PDMS). The dispersed clay/PDMS nanocomposite shows an order of magnitude increase in the dynamic storage modulus at low frequencies, accompanied by the emergence of a ‘solid-like’ plateau, characteristic of dispersed nanocomposites with enhanced clay/polymer interactions.     

Influence of coal characteristics on CO2 gasification

The rate of CO₂ gasification of a coke is one of the most important qualities of metallurgical coke. Many workers are trying to estimate the rate of CO₂ gasification of coke by studying properties of coal, such as the reflectance of vitrinite and the amounts of inertinite and ash in coal. The specific-gravity separation method is used to prepare coals which possess almost the same reflectance, but contain different amounts of inertinite and ash. The relation between the rate of gasification and the properties of coal is quantitatively explained.     

Methodologies for chemical utilization of CO2 to valuable compounds through molecular activation by efficient catalysts

The reactions of CO₂ with oxirane to produce cyclic carbonate, and with aziridine to afford oxazolidine have been of interest as a useful method for its fixation by a chemical process. Highly efficient processes employing recyclable CO₂-phlilic homogeneous catalyst were devised for environmentally benign synthesis of cyclic carbonates and oxazolidinones under supercritical CO₂ without any organic solvent. These processes represent pathways for greener chemical fixations of CO₂ to afford industrial useful materials such as organic carbonates and oxazolidinones with great potential applications.     

Synthesis of cyclic carbonate from vinyl cyclohexene oxide and CO2 using ionic liquids as catalysts

Synthesis of cyclic carbonate from 4-vinyl-1-cyclohexene-1,2-epoxide (VCHO) and carbon dioxide was investigated without using any solvent in the presence of ionic liquid as a catalyst. Ionic liquids based on 1-alkylmethylimidazolium salts of different alkyl groups (ethyl, butyl, hexyl, octyl) and different anions (Cl⁻, BF₄⁻, PF₆⁻) were used as catalysts. The conversion of VCHO was affected by the structure of the imidazolium salt ionic liquids; the ones with the cations of bulkier alkyl chain length and with more nucleophilic anion showed better reactivity. Reaction temperature, carbon dioxide pressure, and zinc halide cocatalyst enhanced the addition of CO₂ to VCHO. Semi-batch operation with continuous supply of carbon dioxide showed higher VCHO conversion than batch operation did.