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In this study, tung oil was polymerized with a dimaleimide (4,4’-methylene-bis(N-phenylmaleimide) (MPMI) and two diacrylates (poly(propylene glycol) diacrylate (PPGDA) and bisphenol A glycerolate diacrylate (BPAGDA) via Diels-Alder reaction (DA reaction) to prepare pressure-sensitive adhesives (PSAs). On the one hand, the polymer of tung oil and MPMI was readily prepared however it was too rigid to serve as a PSA. On the other hand, the polymerization of tung oil with PPGDA or BPAGDA resulted in PSAs with peel strengths ranging from 0.1 to 0.2 N cm−1 and loop tacks ranging from 0.4 to 0.5 N. Nevertheless, tung oil reacted readily with acrylic acid to form adducts (TOAA) with lower content of conjugated diene groups than those of tung oil. The use of TOAAs instead of tung oil to polymerize PPGDA failed to increase the peel strength of the resulting PSAs. However, polymerizations of TOAAs with BPAGDA resulted in PSAs with much higher peel strengths and much higher loop tacks than the polymerization of tung oil with BPAGDA. In addition, the introduction of a small amount of MPMI in the polymerization of TOAA and PPGDA significantly shortened the curing time.  相似文献   
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以生物柴油中的亚油酸甲酯与马来酸二丁酯(DBM)为原料,分别以碘、固体碱为催化剂或在仅加热的条件下合成了C22-三酸三酯。采用傅里叶变换红外光谱(FTIR)、核磁共振(NMR)和质谱(MS)对产物结构进行表征。结果表明,以碘作为催化剂时,生成具有环己烯结构的C22-三酸三酯,反应为Diels-Alder环加成反应;以固体碱KOH/活性白土作催化剂时,生成主链具有共轭结构的悬挂型C22-三酸三酯,反应可能按照碳负离子历程进行;在不用催化剂、仅加热的条件下,也生成主链具有共轭结构的悬挂型C22-三酸三酯,反应可能按照自由基反应机理进行。  相似文献   
4.
维生素B6是一种重要的水溶性维生素,为人体和动物生长所必需,因此被广泛用于医药、食品及饲料添加剂等领域。本文综述了近年来维生素B6的合成研究进展,分别介绍了化学合成方法及微生物法在维生素B6合成中的应用,比较了各法的优缺点,并对研究前景进行了展望。  相似文献   
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Modular ligation strategies for the functionalization of polymeric microspheres provide new perspectives for their applications in material science. In the current trend article we highlight variable synthetic procedures for generating functional microspheres via orthogonal modular conjugation chemistries. An overview of the different surface chemistries available is provided, followed by surface-sensitive characterization techniques relevant for the microparticles. Finally, we explore future trends in modular orthogonal modification approaches on microparticles and provide an outlook on the perspectives that the field of surface-modification of polymeric microparticles holds.  相似文献   
6.
The synthesis of nanoengineered materials with precise control over material composition, architecture and functionality is integral to advances in diverse fields, including biomedicine. Over the last 10 years, click chemistry has emerged as a prominent and versatile approach to engineer materials with specific properties. Herein, we highlight the application of click chemistry for the synthesis of nanoengineered materials, ranging from ultrathin films to delivery systems such as polymersomes, dendrimers and capsules. In addition, we discuss the use of click chemistry for functionalizing such materials, focusing on modifications aimed at biomedical applications.  相似文献   
7.
The current review focuses on the relevance and practical benefit of interpolymer radical coupling methods. The latter are developing rapidly and constitute a perfectly complementary macromolecular engineering toolbox to the controlled radical polymerization techniques (CRP). Indeed, all structures formed by CRP are likely to be prone to radical coupling reactions, which multiply the available synthetic possibilities. Basically, the coupling systems can be divided in two main categories. The first one, including the atom transfer radical coupling (ATRC), silane radical atom abstraction (SRAA) and cobalt-mediated radical coupling (CMRC), relies on the recombination of macroradicals produced from a dormant species. The second one, including atom transfer nitroxide radical coupling (ATNRC), single electron transfer nitroxide radical coupling (SETNRC), enhanced spin capturing polymerization (ESCP) and nitrone/nitroso mediated radical coupling (NMRC), makes use of a radical scavenger in order to promote the conjugation of the polymer chains. More than a compilation of macromolecular engineering achievements, the present review additionally aims to emphasize the particularities, synthetic potential and present limitations of each system.  相似文献   
8.
The number of unique chemical substances registered by the Chemical Abstracts Service passed the 50 million mark in September 2009. The vast majority of these substances were brought into existence by chemical synthesis, a human activity that has grown immensely powerful and continues to advance at an ever-accelerating pace. It would not be unreasonable for the average layman to assume that chemists must now be able to synthesize everything imaginable; however, that Utopian level of success has not been achieved. Some molecular targets remain beyond the reach of chemical synthesis by present day methods. When fullerenes and carbon nanotubes were discovered near the end of the 20th century, for example, scientists quickly recognized that chemical methods to synthesize such large, curved, polycyclic aromatic structures simply did not exist. Since that time, progress has been made on the development of methods for this purpose, and the present article recounts some of the advances along those lines that have been made in the author’s laboratory.  相似文献   
9.
松油醇副产物在催化剂磷酸和助催化剂碘作用下催化异构同时与马来酸酐发生Diels-Alder反应,生成1-异丙基-4-甲基二环[2,2,2]-5-辛烯-2,3-二酸酐(TMA)。运用正交实验确定了合成TMA的最佳合成条件:反应温度155℃,催化剂质量分数为1.5%,助催化剂质量分数为0.05%,n(副产物主成分)∶n(马来酸酐)=2.2∶1,反应时间为2 h,在该条件下,TMA的收率为86.2%。利用红外光谱、核磁共振氢谱、质谱等方法对TMA结构进行了表征。  相似文献   
10.
Following the great interest in polymers based on degradable monomers and degradable cross-linkers, there is now an increasing activity in the controlled synthesis of polymers using degradable initiators. The degradation of polymers bearing residues of degradable initiators has three unique effects: (a) creation of functional end-groups, (b) controlled reduction in molecular weight, and (c) controlled reduction in the degree of branching. Degradation of such polymers has been done for various reasons, including the production of end-functionalized polymers with freshly prepared thiol end-groups for specific adsorption on to gold surfaces, the transformation of a physical gel to a solution, the conversion of end-linked networks to end-functionalized star polymers and the characterization of their core functionality, and the fabrication of nanoporous membranes by the etching of cylindrical nanophases out of a diblock copolymer film. To date, a variety of labile groups have been employed in these initiators, with most notable example the disulfide, while some other groups are yet to be used.  相似文献   
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