Ethylene-octene copolymer (POE) samples exposed to γ-radiation under a series doses were investigated using solid state ~ 13 C-NMR.The chemical shifts of POE were assigned, and the peak evolution as a function of rad...Ethylene-octene copolymer (POE) samples exposed to γ-radiation under a series doses were investigated using solid state ~ 13 C-NMR.The chemical shifts of POE were assigned, and the peak evolution as a function of radiation dose was discussed.An obviously chain scission was found near the branch carbons, and the ~ 13 C-NMR spectra of the corresponding gels confirmed the result.Linewidths of irradiated POE samples of various absorbed doses were observed to which were related to the molecular mobility of the radiation-crosslinked polymer.展开更多
Lithium perchlorate/poly（ethylene oxide）complex,as potential polymer electrolytes,has attracted much research interests in the past decades,due to its great applicational significance.However,despite of great effort...Lithium perchlorate/poly（ethylene oxide）complex,as potential polymer electrolytes,has attracted much research interests in the past decades,due to its great applicational significance.However,despite of great efforts,the mechanism of ion conducting of the system is still a topic with debates.In this work,the（）13C CP/MAS spectra of a series of PEO/LiClO4 complexes were measured with different compositions.It is found that for the extensively dried samples,the（）13C CP/MAS spectrum can exhibit up to 11 narrow peaks and the characteristics of the spectrum varies greatly with the composition.The（）13C spin-lattice relaxation time（T1）of these narrow peaks are found to be comparable to that of the neat PEO crystalline region,indicating these narrow peaks are corresponding to the complexed crystalline structures.On the other hand,the（）1H T1ρ of the narrow peaks are much longer than that of the neat PEO crystalline region,suggesting that the chain motion of PEO in the complex is greatly restricted due to the interaction between the oxygen of PEO and Li+.The aforementioned 11 peaks are assigned to three complexed crystalline structures.The conductivity of the complex sample decreases greatly when [O]∶ molar ratio decreases to 4∶1,while half of the （）13C peaks that are attributed to one crystalline structure varnish,indicating that there should exist certain kind of correlation between the complexed crystalline structure and the conductivity.展开更多
2021年河北省地质调查院在冀东地区中元古代雾迷山组地层中发现了锂的超常富集现象,这是中国首次在前寒武纪地层中发现的黏土型锂资源。该富锂岩系厚度大、分布广泛、层位稳定,Li2O品位为0.1~0.42 wt%,具有巨大的找矿潜力。作为新的赋...2021年河北省地质调查院在冀东地区中元古代雾迷山组地层中发现了锂的超常富集现象,这是中国首次在前寒武纪地层中发现的黏土型锂资源。该富锂岩系厚度大、分布广泛、层位稳定,Li2O品位为0.1~0.42 wt%,具有巨大的找矿潜力。作为新的赋锂层位,锂的赋存状态直接关系到本次发现的黏土型锂资源是否具有勘探开发意义。文章利用了X射线衍射(XRD)、热分析(TG-DTG)、傅里叶变换红外光谱(FTIR),查明研究区富锂岩石主要由白云石、石英和伊利石、伊蒙混层等黏土矿物组成,进一步通过固体核磁共振谱(solid state NMR)、飞行时间二次离子质谱(TOF-SIMS)、黏土矿物提纯和Na离子交换实验等技术方法,揭示了雾迷山组富锂岩系中的锂主要以类质同象替换方式的方式赋存于伊利石和伊蒙混层之中,极少量以离子吸附形式赋存于黏土矿物层间或表面。研究结果为今后在冀东地区开展黏土型锂资源的选冶和开采工作提供重要的理论基础和技术支持。展开更多
For the production of reactive polyurethane cross-linkinger and curing agents, 2, 4-diisocyanate toluene （TDI） terpolymer, which possesses the rigid structures of hexatomic ring and three reactive functional groups,...For the production of reactive polyurethane cross-linkinger and curing agents, 2, 4-diisocyanate toluene （TDI） terpolymer, which possesses the rigid structures of hexatomic ring and three reactive functional groups, was synthesized and characterized by the Fourier transform infrared （FFIR）, the gel permeation chromatography （GPC） and the chemical analysis methods. The reaction conditions were studied and optimized. A tracking research on the polymerization process of TDI was taken by using the GPC. The formation processes of the terpolymer, oligomers and higher-polymers were also dealt with. Results show that the TDI terpolymer can be prepared in the presence of Cat-3 catalyst and at the reaction temperature of （60 ±2）℃. The reaction time is short, its outcomes have narrow molecular weights distribution, namely molecular weights from 530 to 550, Mw/Mn =1.10, and the mass fraction of NCO is （25. 0 ± 0. 5）%. With the reaction time prolonging, however, TDI can be further higher-polymedzed to form higher-polymers. Benzoyl chloride （0. 4%, mass fraction）, as the stabilizing agent, can effectively inhibit the occurrence of higher-polymerization. The obtained TDI terpolymer can be stable for more than half a year.展开更多
文摘Ethylene-octene copolymer (POE) samples exposed to γ-radiation under a series doses were investigated using solid state ~ 13 C-NMR.The chemical shifts of POE were assigned, and the peak evolution as a function of radiation dose was discussed.An obviously chain scission was found near the branch carbons, and the ~ 13 C-NMR spectra of the corresponding gels confirmed the result.Linewidths of irradiated POE samples of various absorbed doses were observed to which were related to the molecular mobility of the radiation-crosslinked polymer.
文摘Lithium perchlorate/poly（ethylene oxide）complex,as potential polymer electrolytes,has attracted much research interests in the past decades,due to its great applicational significance.However,despite of great efforts,the mechanism of ion conducting of the system is still a topic with debates.In this work,the（）13C CP/MAS spectra of a series of PEO/LiClO4 complexes were measured with different compositions.It is found that for the extensively dried samples,the（）13C CP/MAS spectrum can exhibit up to 11 narrow peaks and the characteristics of the spectrum varies greatly with the composition.The（）13C spin-lattice relaxation time（T1）of these narrow peaks are found to be comparable to that of the neat PEO crystalline region,indicating these narrow peaks are corresponding to the complexed crystalline structures.On the other hand,the（）1H T1ρ of the narrow peaks are much longer than that of the neat PEO crystalline region,suggesting that the chain motion of PEO in the complex is greatly restricted due to the interaction between the oxygen of PEO and Li+.The aforementioned 11 peaks are assigned to three complexed crystalline structures.The conductivity of the complex sample decreases greatly when [O]∶ molar ratio decreases to 4∶1,while half of the （）13C peaks that are attributed to one crystalline structure varnish,indicating that there should exist certain kind of correlation between the complexed crystalline structure and the conductivity.
文摘2021年河北省地质调查院在冀东地区中元古代雾迷山组地层中发现了锂的超常富集现象,这是中国首次在前寒武纪地层中发现的黏土型锂资源。该富锂岩系厚度大、分布广泛、层位稳定,Li2O品位为0.1~0.42 wt%,具有巨大的找矿潜力。作为新的赋锂层位,锂的赋存状态直接关系到本次发现的黏土型锂资源是否具有勘探开发意义。文章利用了X射线衍射(XRD)、热分析(TG-DTG)、傅里叶变换红外光谱(FTIR),查明研究区富锂岩石主要由白云石、石英和伊利石、伊蒙混层等黏土矿物组成,进一步通过固体核磁共振谱(solid state NMR)、飞行时间二次离子质谱(TOF-SIMS)、黏土矿物提纯和Na离子交换实验等技术方法,揭示了雾迷山组富锂岩系中的锂主要以类质同象替换方式的方式赋存于伊利石和伊蒙混层之中,极少量以离子吸附形式赋存于黏土矿物层间或表面。研究结果为今后在冀东地区开展黏土型锂资源的选冶和开采工作提供重要的理论基础和技术支持。
文摘For the production of reactive polyurethane cross-linkinger and curing agents, 2, 4-diisocyanate toluene （TDI） terpolymer, which possesses the rigid structures of hexatomic ring and three reactive functional groups, was synthesized and characterized by the Fourier transform infrared （FFIR）, the gel permeation chromatography （GPC） and the chemical analysis methods. The reaction conditions were studied and optimized. A tracking research on the polymerization process of TDI was taken by using the GPC. The formation processes of the terpolymer, oligomers and higher-polymers were also dealt with. Results show that the TDI terpolymer can be prepared in the presence of Cat-3 catalyst and at the reaction temperature of （60 ±2）℃. The reaction time is short, its outcomes have narrow molecular weights distribution, namely molecular weights from 530 to 550, Mw/Mn =1.10, and the mass fraction of NCO is （25. 0 ± 0. 5）%. With the reaction time prolonging, however, TDI can be further higher-polymedzed to form higher-polymers. Benzoyl chloride （0. 4%, mass fraction）, as the stabilizing agent, can effectively inhibit the occurrence of higher-polymerization. The obtained TDI terpolymer can be stable for more than half a year.
