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Chain Dynamics Heterogeneity in Plasticized Poly(vinyl butyral)(PVB) as Elucidated by solid-state nmr

Chinese Journal of Polymer Science 2024年第1期42卷 113-124,I0010页

作者： Jing Lv Xu Chen Zi-Shuo Wu Ya-Hui Li Wei Chen National Synchrotron Radiation Laboratory Anhui Provincial Engineering Laboratory of Advanced Functional Polymer FilmCAS Key Laboratory of Soft Matter ChemistryUniversity of Scienceand Technology of ChinaHefei 230026China

The chain dynamics heterogeneity of the poly(vinyl butyral)(PVB) plasticized by triethylene glycol bis(2-ethylhexa noate)(TEG-EH) was investigated by various solid-state nmr *** plasticized PVB shows two domains in distinct molecular dynamics differences,namely,rigid and soft domains,where the latter is the plasticizer-rich *** time domain low field nmr was first used to investigate the dynamics heterogeneity of the plasticized PVB,and the results show the decreasing activated energy of components in the soft domain of plasticized PVB(E_a=20.2 kJ/mol) as compared with that of the pristine one(E_a=24.3 kJ/mol).Detailed dynamics heterogeneity was obtained by high-field nmr with site-specific *** quadrupole-echo ~2H-nmr was adopted to elucidate the dynamics heterogeneity of the vinyl alcohol(VA) units,where only the hydroxyl group of VA is *** ~1H-^(13)C WISE nmr spectra show that there is not much difference in the mobility of the VB unit in PVB with and without plasticizer,whereas the glass transition temperature differed by approximately 53℃.This is further supported by Torchia's T_1 relaxation *** origin of such an unusual phenomenon is attributed to the critical role of the remaining VA(~22%) in the soft domain,where the VA units locally aggregate through hydrogen ***,the existence of a mobility gradient in the VB unit has been ***,the mobility difference for VB with different stereo-geometry(meso or racemic conformation) is observed for the first *** indicates the importance of modulating the ratio of meso over racemic VB for controlling the macroscopic perfo rmance of PVB.

关键词： Poly(vinyl butyral) Dynamics heterogeneity Plasticizer solid state nmr

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solid state nmr Study of Polystyrene Nanolatex Particles(I) ^(13)C Spin-Lattice Relaxation Time

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Chinese Chemical Letters 2001年第4期12卷 353-354页

作者： Ya Lin TANG Xiao Zhong QU Liu Sheng CHEN Xi Gao JIN Institute of Chemistry Chinese Academy of SciencesBeijing 100080

C spin-lattice relaxtion times for polystyrene nanolatex particles have been investigated. It was found that the dramatic increase at 80℃ annealing temperature is well below the Tg temperature of bulk polystyrene, the increase of relaxation time of aromatic carbons is larger than that of for aliphatic carbons at transition annealing temperature.

关键词： Polystyrene nanolatex particles solid state nmr spin-lattice relaxation time

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solid state nmr study of hydrogen bonding, miscibility, and dynamics in multiphase polymer systems

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中国化学前沿:英文版 2011年第3期6卷 173-189页

作者： Weigui FU Pingchuan SUN Department of Materials Science and Engineering School of Materials Science and EngineeringTianjin Polytechnique UniversityTianjin 300160China Key Laboratory of Functional Polymer Materials Ministry of EducationInstitute of Polymer Chemistry and College of ChemistryNankai UniversityTianjin 300071China

The application of solid state nmr(SS nmr)to the study of multiphase polymer systems is growing *** article aims to provide an overview of the current state of development of this field,paying particular attention to the study of hydrogen bonding in hydrogen-bonded polymer materials through SS nmr *** effection of hydrogen bonds on the miscibility,phase separation and dynamic behavior of selected systems will also be discussed,based on work during the last 10 to 15 years.

关键词： solid state nmr hydrogen bonding miscibility dynamics multiphase polymer

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Thermostability of Nanosized HZSM-5 Zeolite

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Chinese Journal of Catalysis 2000年第3期21卷 195-196页

作者： ZHANG Weiping 1, HAN Xiuwen 1, LIU Xiumei 1, BAO Xinhe 1, GUO Xinwen 2, WANG Xiangsheng 2 (1 state Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, The Chinese Academy of Sciences, Dalian 116023, China 2 Laboratory of Comprehens 中科院大连化学物理所催化基础国家重点实验室辽宁大连 1 1 6 0 2 大连理工大学辽宁大连 1 1 6 0 1

The thermostability of nanosized HZSM-5 zeolite was studied using multinuclear solid-state nmr technique. Nanosized zeolites have received considerable attention for their unique catalytic properties. When the crystal size of HZSM-5 is reduced to nanoscale, it exhibits higher catalytic activity, less coke, and longer catalytic life in CH3OH conversion to hydrocarbons and C2H4 oligomerization. It was found that thermostability of nanosized HZSM-5 is not as good as that of microsized HZSM-5, especially at higher temperatures. It can be ascribed to two processes: dealumination and desilicification in nanosized HZSM-5 during calcination. For microsized HZSM-5, the dealumination dominates and there is much less desilicification. These are related with the higher energy of Si and Al atoms on the surface of nanosized HZSM-5. Thus, they can be more easily extracted from the framework upon thermal treatment.

关键词： nanosized HZSM 5 zeolite thermostability solid state nmr

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13C Shielding Tensors and 13C-14N Dipolar Tensors in Single Crystal Di-glycine Oxalate

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Progress in Natural Science:Materials International 1993年第1期3卷 60-68页

作者：傅日强胡建治叶朝辉吕孟凯 Academia Sinica Institute of Crystal Materials Jinan 250100 PRC Shangdong University state Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics Wuhan 430071

The13C shielding tensors and13C-14N dipolar tensors in single crystal di-glycine oxalate(i.e.2NH3~- CH2COO~-·2COOH,abbreviated as DGO)have been determined in this *** principalelements of the shielding tensors of carboxyl carbons for glycine and oxalate in DGO(i.e.σ1,σ22,σ33)are247.5,168.2,105.6 ppm and 246.6,150.6,106.8 ppm,*** σ22for each group lies in theCOO plane,and is nearly along the C=O *** tensors are rotated 7°and 9°around their σ22so thatthe most shielding component σ33are tilted off the perpendicular to the COO plane by 7°and 9°for glycineand oxalate,*** considering13C-14N dipolar interaction,the shielding tensor of themethylene,i.e.Cαhas been determined unambiguously in the molecular frame,and the length of C-Nbond is 1.57,which agrees well with the X-ray *** comparison with the existing results of glycineand oxalic acid single crystals,the structural differences in DGO are given.

关键词： solid state nmr shielding tensor dipolar tensor di-glycine oxalate

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Study on structural and compositional transitions of coal ash by using nmr

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Journal of Coal Science & Engineering(China) 2012年第1期18卷 80-87页

作者： Lin, Xiong-chao Ideta, Keiko Miyawaki, Jin Takebe, Hiromichi Wang, Yong-gang Yoon, Seong-Ho Mochida, Isao Interdisciplinary Graduate School of Engineering Sciences Kyushu University Fukuoka Japan Institute for Materials Chemistry and Engineering Kyushu University Fukuoka Japan Graduate School of Science and Engineering Ehime University Matsuyam Japan School of Chemical & Environmental Engineering China University of Mining and Technology (Beijing) Beijing China

Structural and compositional transitions of Datong coal ash and its CaCO3 additional effects were carefully exam- ined at a temperature range of 300 to 1 600℃ by using XRD and solid state nmr. The quantitative estimation of amorphous structures of ashes can be successfully obtained through the analyses of solid state nmr spectra. Viscosity of molten ash and its changes with CaCO3 addition were also evaluated up to 1 700 ℃ by using a rotary type viscometer. Glasses with poor crystalline and amorphous phase were continuously formed through the eutectic reaction of silica above fusing temperature （FT〉1 500 ℃） that caused broadening and shift of 29Si and 27A1 peaks in nmr results. With the additional amount of CaCO3 increasing, the peaks shifted to downfield obviously; the fraction of Si（OA1）0（OSi）4 decreased, while that of Si（OA1）l（OSi）l at 84.3 x 10-6 increased apparently. These transitions indicated the destruction of large alumina-silicate framework into small segments by the addition of Ca ion.

关键词： coal gasification coal ash viscosity solid state nmr

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无溶剂法合成ZSM-5的晶化机理研究（英文）

无溶剂法合成ZSM-5的晶化机理研究（英文）

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第18届全国分子筛学术大会

作者：刘小龙王强褚月英邓风中科院物数所

＜正＞Our experimental results demonstrated that both the TPA ions and the hydrogen bonds direct the crystallization process of silicate species around the TPA ions to form the ZSM-5 zeolite *** acting as coordination centers for water molecules and silicate anions,TPA cations also provide the blueprint for the spatial architecture of the inorganic-organic composite

关键词： Solvent-free synthesis method solid state nmr ~2H MAS nmr

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