Carbon-13 NMR analysis of the polymer microstructure of a cured-bis(maleimide)-styrene thermoset resin

1992 ◽  
Vol 25 (17) ◽  
pp. 4285-4289 ◽  
Author(s):  
H. Winter ◽  
G. P. M. Van der Velden
RSC Advances ◽  
2015 ◽  
Vol 5 (120) ◽  
pp. 98929-98933 ◽  
Author(s):  
Liping Hou ◽  
Wei Wang ◽  
Jianfang Sheng ◽  
Changcheng Liu

Synthesis and characterization of an ethylene/9-dencen-1-ol copolymer revealed the effect of polymerization conditions, catalysts and comonomer on the activity and polymer microstructure.


2019 ◽  
Vol 52 (18) ◽  
pp. 7073-7080 ◽  
Author(s):  
Michael Weger ◽  
Philipp Pahl ◽  
Fabian Schmidt ◽  
Benedikt S. Soller ◽  
Philipp J. Altmann ◽  
...  

Author(s):  
K. Siangchaew ◽  
J. Bentley ◽  
M. Libera

Energy-filtered electron-spectroscopic TEM imaging provides a new way to study the microstructure of polymers without heavy-element stains. Since spectroscopic imaging exploits the signal generated directly by the electron-specimen interaction, it can produce richer and higher resolution data than possible with most staining methods. There are basically two ways to collect filtered images (fig. 1). Spectrum imaging uses a focused probe that is digitally rastered across a specimen with an entire energy-loss spectrum collected at each x-y pixel to produce a 3-D data set. Alternatively, filtering schemes such as the Zeiss Omega filter and the Gatan Imaging Filter (GIF) acquire individual 2-D images with electrons of a defined range of energy loss (δE) that typically is 5-20 eV.


2006 ◽  
Vol 71 (10) ◽  
pp. 1470-1483 ◽  
Author(s):  
David Šaman ◽  
Pavel Kratina ◽  
Jitka Moravcová ◽  
Martina Wimmerová ◽  
Zdeněk Wimmer

Glucosylation of the cis- and trans-isomers of 2-(4-methoxybenzyl)cyclohexan-1-ol (1a/1b, 2a/2b, 1a or 2a) was performed to prepare the corresponding alkyl β-D-glucopyranosides, mainly to get analytical data of pure enantiomers of the glucosides (3a-6b), required for subsequent investigations of related compounds with biological activity. One of the employed modifications of the Koenigs-Knorr synthesis resulted in achieving 85-95% yields of pure β-anomers 3a/3b, 4a/4b, 3a or 4a of protected intermediates, with several promoters and toluene as solvent, yielding finally the deprotected products 5a/5b, 6a/6b, 5a or 6a as pure β-anomers. To obtain enantiomerically pure β-anomers of the target structure (3a, 4a, 5a and 6a) for unambiguous structure assignment, an enzymic reduction of 2-(4-methoxybenzyl)cyclohexan-1-one by Saccharomyces cerevisiae whole cells was performed to get (1S,2S)- and (1S,2R)-enantiomers (1a and 2a) of 2-(4-methoxybenzyl)cyclohexan-1-ol. The opposite enantiomers of alkyl β-D-glucopyranosides (5b and 6b) were obtained by separation of the diastereoisomeric mixtures 5a/5b and 6a/6b by chiral HPLC. All stereoisomers of the products (3a-6b) were subjected to a detailed 1H NMR and 13C NMR analysis.


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