降冰片烯与乙炔基官能化苯并恶嗪单体研究

采用溶剂法合成了含有降冰片烯和乙炔基团的苯并恶嗪单体(oHPNI-ac)。通过核磁共振氢谱(~1H-NMR)和傅里叶变换红外光谱(FT-IR)证实了其分子结构,并以示差扫描量热分析(DSC)和原位红外图谱(in situ FT-IR)揭示了其固化行为。结果表明,oHPNI-ac的起始固化温度为205℃,固化峰值温度为224℃。oHPNI-ac中降冰片烯的碳碳双键与乙炔基的碳碳三键可在恶嗪环开环聚合过程中交联,从而降低了降冰片烯双键的固化温度。通过Kissinger方法和Ozawa方法计算得到该苯并恶嗪活化能分别为94.6,97.1 kJ/mol,且推测得到该单体的固化反应动力学方程。     

N-酰化咪唑啉-2-亚胺镍催化剂制备环烯烃共聚物

在助催化剂二氯乙基铝(EtAlCl_2)活化作用下,以N-酰化咪唑啉-2-亚胺镍配合物有效催化了降冰片烯/1-己烯共聚,制备出含1-己烯柔性支链的聚(降冰片烯/1-己烯)环烯烃共聚物,研究了助催化剂用量、反应温度及1-己烯反应单体用量对催化剂催化活性及所得聚合物结构和性质的影响。结果表明,N-酰化咪唑啉-2-亚胺镍配合物不仅可高活性催化降冰片烯/1-己烯共聚[催化活性最高达3.88×10~5 g/(mol·h)],且即使在120℃下仍可有效催化合成出高1-己烯含量的环烯烃共聚物,热稳定性良好;同时,随着EtAlCl_2用量和1-己烯反应单体用量增加,聚合物中1-己烯单体插入率逐渐增大,最高可达7.11% (物质的量分数),但配合物催化活性、聚合物数均分子量及玻璃化转变温度呈下降趋势;另外,升高聚合温度有助于提高催化活性及1-己烯单体插入率,但易导致聚合物分子量减小。由此可见,在该催化体系下通过调整EtAlCl_2用量,反应温度及1-己烯反应单体用量,即可实现对环烯烃共聚物的结构性能进行有效调控。     

用负载钛催化剂催化1-丁烯与乙烯基降冰片烯共聚合

以负载钛体系(TiCl4/MgCl2,简称Ti)为主催化剂,三异丁基铝(简称Al)为助催化剂,加氢汽油为溶剂,合成了1-丁烯/乙烯基降冰片烯共聚物,探讨了反应条件对聚合的影响,并用红外光谱、核磁共振氢谱和差示扫描量热法对共聚物结构和热性能进行了表征和测试.结果表明,聚合的最佳反应条件为乙烯基降冰片烯的投料摩尔分数7.6%、Ti/单体(摩尔比) 10-4、Al/Ti(摩尔比) 500、反应温度40 ℃和反应时间10 h;通过与聚1-丁烯的对比,证明共聚后体系中引入了双键和大体积取代基,共聚物中乙烯基降冰片烯链段的摩尔分数为1.98%.     

乙烯基降冰片烯的合成

本文研究了乙丙橡胶第三单体乙叉降冰片烯的中间体－乙烯基降冰片烯的合成方法及最佳工艺条件。     

溴系阻燃剂BN451的合成及其在聚丙烯中的应用

通过先溴化后酰亚胺成环法合成了阻燃剂BN451(N,N'-1,2-乙烷-双[5,6-二溴降冰片烷-2,3-二酰亚胺]),红外光谱图表明存在目标产品的特征吸收峰。讨论了在降冰片-5-烯-2,3-二酸酐溴化过程中反应温度、N,N-二甲基甲酰胺、乙二胺用量对产率的影响。在较佳反应条件下,即反应温度40℃,降冰片-5-烯-2,3-二酸酐13g,N,N-二甲基甲酰胺11mL,乙二胺13mL时,反应收率为70%。将阻燃剂BN451按不同比例与聚丙烯混合,探索了阻燃聚丙烯阻燃性和拉伸强度随阻燃剂含量的变化规律。     

降冰片烯酰亚胺型双苯并嗪的合成及性能

首先用降冰片烯二酸酐、对氨基苯酚为原料合成降冰片烯酰亚胺(NI),然后用合成的NI、4,4-二氨基二苯醚(ODA)和多聚甲醛为原料进行Mannich反应合成出降冰片烯酰亚胺型双苯并嗪(NI-BOZ),经高温固化后形成热固性树脂。用FTIR、1H NMR、13C NMR分析了NI和NI-BOZ的化学结构,证实了所得的目标产物;用DSC对NI-BOZ的固化动力学进行研究;用DMA和TGA分析了NI-BOZ的固化物的热性能。结果表明:NI-BOZ的固化反应活化能为86.27 k J·mol-1,反应级数为0.91;poly(NI-BOZ)树脂空气条件下的玻璃化转变温度为215℃,氮气条件下失重5%的温度为445℃,失重10%的温度为467℃,在800℃的残碳率为63%。     

苯胺基肟类钯催化剂的合成及其催化烯烃聚合的研究

本文通过一步法制备了新型的苯胺基肟类中性钯催化剂,并通过核磁氢谱、核磁碳谱、元素分析对相应的配体和催化剂结构进行了测试表征,结果表明,成功制备了所设计的配体以及相应催化剂。进一步研究了钯催化剂对催化降冰片烯单体的均聚合行为,结果表明,钯催化剂在助催化剂dMMAO作用下,可高活性催化降冰片烯单体的均聚合,活性高达540 kg/(mol Pd·h);同时发现,该催化剂的热稳定性好,可以在80℃以较高活性催化降冰片烯单体均聚合。     

亚乙基降冰片烯的合成

近年来,随着三元乙丙橡胶的广泛应用,作为其首选第三单体的亚乙基降冰片烯（ENB）越来越受到关注。综述了ENB的反应机理、合成工艺、生产情况及市场动向。在反应机理方面主要包括先由双环戊二烯在高温下裂解成的环戊二烯与丁二烯经Diels-Alder反应生成中间体乙烯基降冰片烯（VNB）,再经其异构化反应制得亚乙基降冰片烯。重点阐述了乙烯基降冰片烯合成阶段副反应控制的工艺优化,以及VNB异构化阶段不同类型催化剂的影响等。     

乙烯和环烯烃共聚用有机金属催化剂

配位催化共聚是制备环烯烃共聚物的主要方法，目前商品化的环烯烃共聚物主要由乙烯与降冰片烯或者四环十二碳烯共聚得到。共聚单体及其含量是决定环烯烃共聚物性能的关键因素，而决定共聚单体含量的最核心因素是催化剂。本文从催化剂结构的角度出发，综述了乙烯和降冰片烯/四环十二碳烯共聚用有机金属催化剂，从双茂有机金属催化剂、单茂有机金属催化剂、非茂有机金属催化剂、后过渡金属催化剂等部分进行论述，同时论述了催化剂结构及关键聚合工艺（如温度、压力、单体浓度等）对催化活性及共聚单体插入量的重要影响。此外，由于乙烯与四环十二碳烯共聚活性低，未来针对该共聚反应的研究会继续进行。合成更多新结构的配体、开发更高活性的催化剂、构建更经济有效的反应体系将会是新的研究重点。     

N-丙烯酰基邻苯二甲酰亚胺的合成研究

以丙烯酰氯和邻苯二甲酰亚胺钾盐为原料,丙酮为溶剂,合成N-丙烯酰基邻苯二甲酰亚胺。考察了反应原料配比、反应温度和反应时间对反应产率的影响。结果表明,优化反应条件为:n(丙烯酰氯)∶n(邻苯二甲酰亚胺钾盐)=4∶1,在28℃下反应8 h,N-丙烯酰基邻苯二甲酰亚胺的产率为54%。     

Polymers of norbornenyl‐4‐phenol: Dissolution rate characteristics,positive tone photo‐patterning,and polymer properties

Vinyl addition norbornene polymers with phenol pendent groups are obtained by methanolysis of the 4‐acetoxyphenyl norbornene polymer. Thin films of this polymer blended with additives such as norbornene polymers with hexafluoroalcohol pendent groups and diazonaphthoquinone compounds result in linear dissolution in tetramethylammonium hydroxide developer. Good resolution, positive tone patterns are obtained from image‐wise exposure of thin films of blends of the diazonaphthoquinone additives with both phenol pendent norbornene homopolymer and with norbornene copolymers with both phenol and hexafluoroalcohol pendent groups. Properties such as transparency, dielectric constant, chemical, and thermal resistance were determined for cured copolymer compositions containing an epoxy crosslinker. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44952.     

Solvent and aqueous-borne polyolefin coatings obtained by catalytic polymerization

Copolymers of ethylene with various olefins such as hexadecene, undecenol and norbornene were obtained by emulsion and solution catalytic polymerization, using a nickel-based catalytic system. Aqueous-based coatings could be produced from hexadecene-containing copolymers, however these coatings exhibited poor adhesion properties. Adhesion was improved by introducing polar groups, as in the case of poly(undecenol-co-ethylene), but the resulting films were very tacky. Copolymers of ethylene and norbornene were prepared by palladium-catalyzed polymerization. Solvent-based coatings of ethylene–norbornene copolymers were obtained when the incorporation of norbornene in the polymer was higher than 15 mol%. Using EIS experiments, the resulting films were shown to exhibit promising applications as barrier coatings for anticorrosion applications.     

Norbornene polymerization and ethylene/norbornene copolymerization catalyzed by constrained geometry cyclopentadienyl-phenoxytitanium catalysts

Norbornene polymerization and ethylene/norbornene copolymerization were studied using constrained geometry complexes 2-(tetramethylcyclopentadienyl)-4,6-di-tert-butylphenoxytitanium dichloride (1), 2-(tetramethylcyclopentadienyl)-6-tert-butylphenoxytitanium dichloride (2), and 2-(tetramethylcyclopentadienyl)-6-phenylphenoxytitanium dichloride (3) as catalysts with AlⁱBu₃ and Ph₃CB(C₆F₅)₄ as cocatalysts. Polymerization results indicate that these catalyst systems are highly active for both the homopolymerization of norbornene and the copolymerization of ethylene with norbornene. The norbornene homopolymerization is vinyl addition polymerization. Ethylene/norbornene copolymers with high norbornene incorporation (>50%) were easily obtained with these catalyst systems by increasing the norbornene feed concentration. The produced polymers were characterized by ¹³C NMR, IR, DSC and GPC.     

The partial oxidation of norbornene over a silver catalyst under steady state conditions

The continuous oxidation of norbornene (C₇H₁₀) by molecular oxygen over a silver catalyst at 500–573 K has been investigated. In contrast to that observed during the temperature programmed reaction of norbornene and oxygen adsorbed on Ag(110) no norbornene epoxide is formed. Instead benzene is the sole partial oxidation product. A stable selectivity of 20 to 25% with fractional conversions up to 0.8 at 573 K could be obtained by inclusion of 15 to 30 ppm dichloroethane in the feed. Separate experiments withexo-norbornene epoxide showed that in the absence of oxygen it was almost completely isomerised to 3-cyclohexene-1-carboxyaldehyde with production of lesser amounts of norcamphor and norbornene. With oxygen present carbon dioxide and small amounts of benzene were also produced. It is concluded that norbornene epoxide cannot be a gas phase intermediate in the production of benzene from norbornene.     

亚乙基降冰片烯的合成

介绍了国外亚乙基降冰片烯的生产技术和科研工作的进展情况。并根据我国实情，阐述了开展亚乙基降冰片烯合成方法的研究对我国实现产业化的必要性和可行性。     

Syndiotactic poly(propene-co-norbornene): Synthesis and properties at low norbornene incorporation

Copolymerizations of propene with norbornene were carried out using a syndiotactic metallocene catalyst at low initial comonomer concentrations for different polymerization times. The influence of the norbornene concentration on the catalytic activity and on the resulting material properties has been analyzed. The copolymer molecular weight decreased drastically when small amounts of norbornene were added in reactions which lasted 30 min. When longer reaction times were used the molecular weight increased with time, however living polymerization was ruled out because the polydispersity was ca. 2. The DSC measurements showed copolymers with low crystallinity or which were completely amorphous.     

Thermal and dynamic mechanical behavior of ethylene/norbornene copolymers with medium norbornene contents

A range of ethylene/norbornene copolymers were synthesized using the commercially available rac‐Et(Ind)₂ZrCl₂ metallocene catalyst. A large window of norbornene contents, between 30 and 55 mol % was used to facilitate the interpretation of the results. The polymers were characterized by means of wide‐angle X‐ray scattering, differential scanning calorimetry, and dynamic mechanical thermal analysis. The X‐ray diffractograms showed two amorphous halos, the low‐angle one increasing in the intensity with norbornene content. Calorimetric and dynamic mechanical results led to a linear relation between the glass transition temperature and the norbornene content. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2159–2165, 2001     

Non-Cp type titanium precatalysts for ethylene/norbornene copolymerization

Ethylene/norbornene monomers were homo- as well as copolymerized using titanium-based non-Cp precatalysts [2-(2,6-dialkylphenylamino)-1-phenylethoxy TiCl₂] in the presence of methylaluminoxane. The precatalysts polymerized ethylene with moderate activities that increased with increase in temperature reaching a maximum yield of polyethylene at 70 °C. However, these catalysts showed relatively low activity towards norbornene homopolymerization. Precatalysts 1ATiCl₂ and 3ATiCl₂ were used for ethylene/norbornene copolymerization. The microstructural analysis of these copolymers suggests that these are alternating copolymers with meso (major) and racemic (minor) sequences. Higher norbornene incorporation in the copolymer was obtained with precatalyst 3ATiCl₂, which is a more “open” catalyst system. The reactivity ratios for ethylene/norbornene copolymerization suggest that these precatalysts show lesser tendency towards norbornene homopropagation in the copolymerization reactions.     

Thiol–norbornene photoclick hydrogels for tissue engineering applications

Thiol–norbornene (thiol–ene) photoclick hydrogels have emerged as a diverse material system for tissue engineering applications. These hydrogels are crosslinked through light‐mediated orthogonal reactions between multifunctional norbornene‐modified macromers [e.g., poly(ethylene glycol) (PEG), hyaluronic acid, gelatin] and sulfhydryl‐containing linkers (e.g., dithiothreitol, PEG–dithiol, biscysteine peptides) with a low concentration of photoinitiator. The gelation of thiol–norbornene hydrogels can be initiated by long‐wave UV light or visible light without an additional coinitiator or comonomer. The crosslinking and degradation behaviors of thiol–norbornene hydrogels are controlled through material selections, whereas the biophysical and biochemical properties of the gels are easily and independently tuned because of the orthogonal reactivity between norbornene and the thiol moieties. Uniquely, the crosslinking of step‐growth thiol–norbornene hydrogels is not oxygen‐inhibited; therefore, gelation is much faster and highly cytocompatible compared with chain‐growth polymerized hydrogels with similar gelation conditions. These hydrogels have been prepared as tunable substrates for two‐dimensional cell cultures as microgels and bulk gels for affinity‐based or protease‐sensitive drug delivery, and as scaffolds for three‐dimensional cell encapsulation. Reports from different laboratories have demonstrated the broad utility of thiol–norbornene hydrogels in tissue engineering and regenerative medicine applications, including valvular and vascular tissue engineering, liver and pancreas‐related tissue engineering, neural regeneration, musculoskeletal (bone and cartilage) tissue regeneration, stem cell culture and differentiation, and cancer cell biology. This article provides an up‐to‐date overview on thiol–norbornene hydrogel crosslinking and degradation mechanisms, tunable material properties, and the use of thiol–norbornene hydrogels in drug‐delivery and tissue engineering applications. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41563.     

Influence of polymerization conditions on microstructure of norbornene-ethylene copolymers made using metallocene catalysts and MAO

When characterized with ¹³C-NMR, it was found that norbornene-ethylene copolymers had a more complicated microstructure when dimethylsilyl bis(indenyl) zirconium dichloride was used as the catalyst compared to ethylene bis(indenyl) zirconium dichloride. One could see more block sequences but less alternating sequences. For both catalysts the highest amounts of block sequences were obtained for high norbornene concentrations, medium to high Al/Zr ratios, and low polymerization temperatures. There were also more alternating sequences for high norbornene concentrations and high polymerization temperatures. The isolated norbornene units (separated by more than one ethylene unit) were all exoconfiguration. No unsaturation was seen. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 63: 1071–1076, 1997