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Chemical Research in Chinese Universities 2006年第6期22卷 787-791页

作者： ZHOU Xiao-ming JIANG Zhen-hua Alan G. MacDiarmid Lab College of Chemistry Jilin University Changchun 130012 P. R. China

The random, block, and alternative copolymers of poly ether sulfone（PES） and poly ether ether sulfone（PEES） were synthesized v/a three kinds of methods. The chemical structures of the three kinds of copolymers were characterized by ^13C NMR. Three kinds of PES/PEES copolymers（ Tg =215 ℃ ）, which were almost identical in composition but different in sequence distribution, were used. Their physical aging process was studied by differential scanning calorimetry（DSC） at three aging temperatures ranging between Tg -15 ℃ and Tg -25℃. The experimental results reveal that the alternative copolymer shows a lower enthalpy relaxation time 〈T〉 and apparent activation energy when compared with the random and block copolymers. The result of the electron-microscopy investigation of the three copolymers that were treated at 200 ℃ for 96 h indicates that the molecular aggregation of the copolymers changed from a randomly coiled amorphous phase to an ordered phase, and the ordered structure of the alternative copolymer was more distinct than that of the random phase. The experimental results of this study suggest that the motion of the sagments is affected by the different molecular-chain sequence distribution.

关键词： Physical aging Apparent activation energy sequence distribution

STUDY ON sequence distribution OF 3, 4-POLYISOPRENE BY 13C-NMR

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Chinese Journal of Polymer Science 1987年第2期5卷 114-119页

作者：谢德民孙菁 Changchun Institute of Applied Chemistry Academia Sinica Changchun Changchun Institute of Applied Chemistry Academia Sinica Changchun

Isoprene can be plymerized with Fe（acac）3-phen-AlEt3catalyst system into a polymer mainly containg 3, 4-unit and capable of crystallizing to some extent. The13C-NMR spectra of 3, 4-polyisoprene synthesized: with Fe-catalyst system were investigated, and the: sequence distribution of cis-1, 4, trons-1, 4 and 3, 4-units and the amount of head-to-head and tail-to-tail linkages of 1, 4 and 3, 4-units were discussed. Results showed that the contents of cis-1, 4, trans-1, 4 and 3, 4-unit calculated from different carbon types were satisfactorily identical, indicating correct assignments of these peaks.

关键词： 13C-NMR 3, 4-Polyisoprene sequence distribution Diene polymerization Fe-catalyst

CRYSTALLIZATION SEGREGATION DSC STUDIES OF PP/PE COPOLYMERS

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Chinese Journal of Polymer Science 2001年第1期19卷 93-96页

作者： Yu Ma Ying Wang Shan-nong Zhu Mao Xu State Key Laboratory of Polymer Physics and Chemistry Center for Molecular Science Institute of ChemistryChinese Academy of SciencesBeijing 100080China

The structural analysis of two PP/PE copolymer samples,1 and 2,was conducted by using^(13)C-NMR,GPC and crystallization segregation DSC(CSDSC)techniques.A pure polypropylene sample was also used for *** was found that the two copolymer samples are very close in composition(the ethylene mol content is 4.3%and 4.5%,respectively),stereoregularity(96%and 97%)and molecular weight(M_(w)=7.0 x 10^(4)and 7.3 x 10^(4);M-(w)/M_(n)=5.0 and 6.1,respectively).While the CSDSC thermograms of the two samples are quite different from each *** 1 shows a higher average melting temperature and a broader distribution of its thermogram These phenomena were explained as an indication of a less uniform distribution of ethylene units along the PP chains for sample *** was noted that CSDSC is a very sensitive and convenient technique for structural studies of copolymers.

关键词： PP/PE copolymer sequence distribution crystallization segregation DSC ^(13)C-NMR

Microstructural Characteristics Analysis of PCE Copolymer from Methyl Allyl Polyethylene Glycol and Methacrylic Acid based on Determination of Monomer Reactivity Ratios

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Journal of Wuhan University of Technology(Materials Science) 2021年第2期36卷 223-229页

作者： WANG Ziming KANG Yaxin PENG Jingying College of Materials Science and Engineering Beijing University of TechnologyBeijing 100124China

The reactivity ratio of monomer and the microstructure of copolymer as polycarboxylate ether(PCE)superplasticizer were *** ethers(PCEs)were synthesized from methyl allyl polyethylene glycol(MAPEG,Mw=2400 g/mol)and methacrylic acid(MAA)via aqueous free radical copolymerization in low conversion(Psequence distribution of the copolymer,the number average length of MAA in the polymerisate were found to decline with the decrease of the mole fraction of MAA in the polymerization *** a result,the distribution of chain segments becomes narrower and the copolymer structure becomes more ***,uniform polymers could be obtained by slowly adding MAA monomer during copolymerization process.

关键词： reactivity ratio polycarboxylate K-T method copolymer sequence distribution

STUDIES ON THE SEGMENTAL STRUCTURE OF POLYESTER-POLYETHER

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Chinese Journal of Polymer Science 1989年第2期7卷 143-149页

作者：陈传福王身国李学芬李执芬冀克俭李立璞 Institute of Chemistry Academia SinicaBeijing

In this paper the change of segment ratio, segmental sequence distribution and randonmess B of PET-PTMG block copolymer have been investigated by IR and ^(13)C-NMR spectra during the polycondensation reaction.

关键词： Polyester-polyether block copolymer Segmental structure sequence distribution Probability Randomness.

STUDY ON THE CHARACTERIZATION OF distribution OF SUBSTITUENTS ALONG THE CHAINOF CARBOXYMETHYL CELLULOSE

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Chinese Journal of Polymer Science 1989年第1期7卷 45-53页

作者：马志艺张维邦李卓美 Institute of Polymer Science Zhongshan University

Four new paranmeters, and , and have been proposed to describe the average length of the sequence of substituted anhydroglucose units and that of unsubstituted ones respectively along the CMC chain. The methods for determining those parameters have also been presented . Six CMC samples have been characterized in terms of intrinsic viscosity, degree of substitution （DS）, index of substitution（SI）;and . It has been proved experimentally that, not only can describe the sequence distribution along the CMC chain, but also can be used for calculating SI and estimating the average degree of substitution in the substituted glucose rings.

关键词： Carboxymethylcellulose Degree of substitution sequence distribution

^(13)C-NMR STUDY OF ETHYLENE-1-OCTENE COPOLYMERS

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Chinese Journal of Polymer Science 1994年第3期12卷 193-200页

作者：徐志康封麟先杨士林 Department of Polymer Science and Engineering Zhejiang University Hangzhou 310027

A ^(13)C-NMR method is presented for a quantitative determination of the respective monomercomposition and sequence distributions in ethylene-1-octene copolymers prepared with supportedtitanium/magnesium catalyst. On the basis of the sequence distributions, the ethylene-1-octenecopolymerization mechanism was studied. It was found that the observed sequence distributions inethylene-1-octene copolymers are satisfactorily predicted by the two-site model M/M,in whichthe copolymerization proceeds according to first-order Markovian statistics at the two differentsites.

关键词： Ethylene-1-Octene copolymer sequence distribution ^(13)C NMR

STUDIES ON THERMOTROPIC LIQUID CRYSTALLINE COPOLYESTERS:POLY (ARYLENE TEREPHTHALATECO-HEXAMETHYLENE TEREFHTHALATE)

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Chinese Journal of Polymer Science 1988年第2期6卷 123-128页

作者：张鸿志汪平平冯新德 Department of Chemistry Peking University Beijing

A series of copolyesters based on terephthaloyl chloride, hexamethylene glycol and hydroquinone or chlorohydroquinone were prepared. The copolymers showed composition-dependent liquid crystalline properties as verified by visual observation of stir-opalescence, polarizing microscope and DSC. The copolyesters with aromatic diol contents over a certain extent (x≥0.2) were thermotropic with wide liquid crystalline temperature ranges. Comparing with the copolyesters based on butylene glycol or ethylene glycol, the minimum fraction of aromatic diol (x value) used to get the liquid crystallinity for all these copolyesters is around 0.2 regardless of the chain lengths of aliphatic glycols. ~1H-NMP studies revealed that copolyesters have microstructure of block sequence distribution and the mesogenie segments shorter than triad with three phenyl nuclei will not provide the liquid crystallinity.

关键词： Liquid crystalline copolyesters Poly(arylene terephthalate-co-hexamethylene terephthalate) Minimum mesogenic fraction sequence distribution Microstrueture parameters/

STUDY ON THE sequence STRUCTURE OF SBR BY ^(13)C—NMR METHOD Ⅰ. ASSIGNMENT FOR UNSATURAT CARBONS SPECTRA

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Chinese Journal of Polymer Science 1990年第1期8卷 17-24页

作者：焦书科陈晓农胡力平严宝珍 Department of Applied Chemistry Beijing Institute of Chemical Technology Beijing

The sequence structures of emulsion-processed SBR and solution-processed (by lithium catalyst) SBR were investigated by ^(13)C-NMR spectroscopy. Seventeen peaks within unsaturated carbon region were recorded under the... 详细信息

关键词： sequence distribution ^(13)C-NMR spectra of SBR Peak assignment for olefinic car- bon atoms.