Cyclic oligomers of poly(ether ketone) (PEK): synthesis, extraction from polymer, fractionation, and characterisation of the cyclic trimer, tetramer and pentamer

2000 ◽  
Vol 10 (9) ◽  
pp. 2011-2016 ◽  
Author(s):  
Abderrazak Ben-Haida ◽  
Howard M. Colquhoun ◽  
Philip Hodge ◽  
David J. Williams
Science ◽  
2019 ◽  
Vol 364 (6441) ◽  
pp. 674-677 ◽  
Author(s):  
Daiki Ikuta ◽  
Yasuaki Hirata ◽  
Shinnosuke Wakamori ◽  
Hiroaki Shimada ◽  
Yusuke Tomabechi ◽  
...  

Cyclodextrins (CDs) are cyclic oligomers of α-1,4-d-glucopyranoside and are known mainly as hexamers to octamers. The central cavities of CDs can retain small molecules, enabling diverse applications. The smallest members, CD3 and CD4, have ring sizes too small to permit the most stable conformations of glucopyranose and have not been accessible synthetically. In this study, we present methods to chemically synthesize both CD3 and CD4. The main factor in the successful synthesis is the creation of a glucopyranose ring conformationally counterbalanced between equatorial- and axial-rich forms. This suppleness is imparted by a bridge between O-3 and O-6 of glucose, which enables the generation of desirable, albeit deformed, conformers when synthesizing the cyclic trimer and tetramer.


2013 ◽  
Vol 781-784 ◽  
pp. 411-414
Author(s):  
Li Song Hu ◽  
Jiang Yu Wu ◽  
Qing Zhong Guo

Preparation of cyclic aryl ketone oligomers containing the iso-phthaloyl moiety by Friedel-Crafts acylation reaction is described. These cyclic oligomers are characterized by a combination of MALDI-TOF-MS and NMR analyses. The cyclic aryl ketone oligomers readily undergo anionic ring-opening polymerization in the melt by using potassium 4, 4-biphenoxide as the initiator, affording linear, high molecular weight poly (ether ketone) s with excellent thermal stability.


1976 ◽  
Vol 41 (9) ◽  
pp. 2510-2518 ◽  
Author(s):  
J. Poláček ◽  
V. Boháčková ◽  
Z. Pokorná ◽  
E. Sinkulová

1991 ◽  
Vol 56 (9) ◽  
pp. 1908-1915 ◽  
Author(s):  
Jaroslav Holeček ◽  
Antonín Lyčka ◽  
Milan Nádvorník ◽  
Karel Handlíř

Infrared spectroscopy and multinuclear (13C, 17O, and 119Sn NMR spectroscopy have been used to study the structure of bis(1-butyl)tin(IV) carboxylates of dicarboxylic acids (1-C4H9)2. Sn(X(COO)2), where X = (CH2)n (n = 0-8), CH=CH (cis and trans) and C6H4 (ortho and para).The crystalline compounds are formed by linear or cyclic oligomers or polymers whose basic building units represent a grouping composed of the central tin atom substituted by two 1-butyl groups and coordinated with both oxygen atoms of two anisobidentate carboxylic groups derived from different molecules of a dicarboxylic acid. The environment of the tin atom has a shape of a trapezoidal bipyramid. When dissolvet in non-coordinating solvents, the compounds retain the oligomeric character with unchanged structure of environment of the central tin atom. In the media of coordinating solvents the bis(1-butyl)tin(IV) carboxylates of dicarboxylic acids form complexes whose central hexacoordinated tin atom binds two molecules of the solvent trough their donor atoms. Carboxylic groups form monodenate linkages in these complexes.


Polymer Chemistry: A Practical Approach in Chemistry has been designed for both chemists working in and new to the area of polymer synthesis. It contains detailed instructions for preparation of a wide-range of polymers by a wide variety of different techniques, and describes how this synthetic methodology can be applied to the development of new materials. It includes details of well-established techniques, e.g. chain-growth or step-growth processes together with more up-to-date examples using methods such as atom-transfer radical polymerization. Less well-known procedures are also included, e.g. electrochemical synthesis of conducting polymers and the preparation of liquid crystalline elastomers with highly ordered structures. Other topics covered include general polymerization methodology, controlled/"living" polymerization methods, the formation of cyclic oligomers during step-growth polymerization, the synthesis of conducting polymers based on heterocyclic compounds, dendrimers, the preparation of imprinted polymers and liquid crystalline polymers. The main bulk of the text is preceded by an introductory chapter detailing some of the techniques available to the scientist for the characterization of polymers, both in terms of their chemical composition and in terms of their properties as materials. The book is intended not only for the specialist in polymer chemistry, but also for the organic chemist with little experience who requires a practical introduction to the field.


2021 ◽  
Vol 56 (18) ◽  
pp. 11174-11185
Author(s):  
Xin Cong ◽  
Jiannan Ren ◽  
Chunhui Xiang ◽  
Xuzhao Gai ◽  
Guibin Wang ◽  
...  

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