排序方式: 共有24条查询结果,搜索用时 31 毫秒
1.
A. Hamou C Devallencourt F. Burel J. M. Saiter M. Belbachir 《Journal of Thermal Analysis and Calorimetry》1998,52(3):697-703
The thermal stability of p-cresol novolac resin was studied by means of DSC, X-ray diffraction, thermogravimetry and SEC investigations.
After 30 thermal cycles in which the same sample was heated, cooled and heated again, without attainment of the temperature
of degradation at any time in the experiment, important structural modifications are observed. At the end of the experiments,
the resin, which is initially highly crystalline, exhibits all the characteristics of a semi-crystalline material.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
2.
3.
4.
Cleavable Binary Dyads: Simplifying Data Extraction and Increasing Storage Density in Digital Polymers
下载免费PDF全文
![点击此处可从《Angewandte Chemie (International ed. in English)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Gianni Cavallo Dr. Salomé Poyer Jean‐Arthur Amalian Florent Dufour Alexandre Burel Dr. Christine Carapito Prof. Laurence Charles Dr. Jean‐François Lutz 《Angewandte Chemie (International ed. in English)》2018,57(21):6266-6269
Digital polymers are uniform macromolecules that store monomer‐based binary sequences. Molecularly stored information is usually extracted from the polymer by a tandem mass spectrometry (MS/MS) measurement, in which the coded chains are fragmented to reveal each bit (i.e. basic coded monomer unit) of the sequence. Here, we show that data‐extraction can be greatly simplified by favoring the formation of MS/MS fragments containing two bits instead of one. In order to do so, digital poly(alkoxyamine phosphodiester)s, containing binary dyads in each repeat unit, were prepared by an orthogonal solid‐phase approach involving successive phosphoramidite and radical‐radical coupling steps. Three different sets of monomers were considered to build these polymers. In all cases, four coded building blocks—two hydroxy‐nitroxides and two phosphoramidite monomers—were required to build the dyads. Among the three studied monomer sets, one combination allowed synthesis of uniform sequence‐coded polymers. The resulting polymers led to clear dyad‐containing fragments in MS/MS and could therefore be efficiently decoded. Additionally, an algorithm was created to detect specific dyad fragments, thus enabling automated sequencing. 相似文献
5.
By-products in the syntheses of 2-(1- and 2-naphthyl)pyridines by successive treatments of 1- and 2-bromonaphthalenes with (a) n-butyllithium in ether and (b) pyridine are identified as 5-butyl-2-(1-naphthyl)pyridine and, tentatively, 5-butyl-2-(2-naphthyl)pyridine, respectively. It is proposed that these by-products result from reaction of intermediate compounds 1-lithio-2-naphthyl-1,2-dihydropyridines and 1-bromobutane. 相似文献
6.
7.
8.
Charlotte Duval Nasreddine Kébir Raphaël Jauseau Fabrice Burel 《Journal of polymer science. Part A, Polymer chemistry》2016,54(6):758-764
Novel fully renewable AA‐BB type non‐isocyanate polyhydroxyurethanes were synthesized by the classical reaction between a diamine and a dicyclocarbonate. Sebacic acid was first reacted with an excess of glycerol carbonate, in presence of DCC and DMPA, leading to a renewable dicyclocarbonate monomer. Then, this monomer was reacted with several renewable diamines, in presence of 1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene (TBD), as organocatalyst, to afford linear and branched polymers. The obtained materials exhibited Tg values varied from ?27 to ?8 °C, Tm values varying from 100 to 165 °C, and thermal stabilities above 200 °C. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 758–764 相似文献
9.
In this article, elastic wave propagation in a homogeneous isotropic elastic medium with a rigid boundary is considered. A method based on the decoupling of pressure and shear waves via the use of scalar potentials is proposed. This method is adapted to a finite element discretization, which is discussed. A stable, energy preserving numerical scheme is presented, as well as 2D numerical results. 相似文献
10.
Fabrice Burel Jean-Pierre Couvercelle Claude Bunel Jean-Marc Saiter 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(6):1091-1102
Abstract A series of α-n-alkyl acrylic acid monomers was synthesized and homopolymerized by a radical route. Methylation of polyacids using diazomethane led to the corresponding methyl esters and allowed physicochemical analysis. The thermal stability of polyacids and polymethyl esters is insensitive to the nature of the alkyl group and to the molecular weight. The glass transition temperature, T g, classically decreases with increases in alkyl group length such as alkyl polymethacrylates. Molecular weight has a drastic influence on T g for short alkyl groups. 相似文献