采用傅里叶变换红外(FT-IR)光谱法研究了二聚脂肪酸二异氰酸酯(DDI)/端羟基聚丁二烯(HTPB)体系的固化反应动力学,并与异佛尔酮二异氰酸酯(IPDI)/HTPB体系进行了比较。初步探索了DDI在HTPB推进剂中的应用。结果表明,DDI/HTPB体系的固化...采用傅里叶变换红外(FT-IR)光谱法研究了二聚脂肪酸二异氰酸酯(DDI)/端羟基聚丁二烯(HTPB)体系的固化反应动力学,并与异佛尔酮二异氰酸酯(IPDI)/HTPB体系进行了比较。初步探索了DDI在HTPB推进剂中的应用。结果表明,DDI/HTPB体系的固化反应为二级反应,表观活化能为37.02 k J·mol-1,相比IPDI/HTPB体系降低了3.5 k J·mol-1,说明DDI的反应活性稍高于IPDI,反应活性适中,可作为低毒固化剂应用于HTPB推进剂中。DDI/HTPB体系推进剂具有较好的常温力学性能,抗拉强度为0.85 MPa时,最大伸长率为44.1%,可基本满足推进剂的常温力学性能要求。展开更多
Based on cryogenic FT-IR spectroscopic studies of hydrogen bonds in cholic acid, two-dimensional FT-IR spectroscopy was applied to enhance our understanding of the hydrogen bonds of cholic acid. Fine spectral structu...Based on cryogenic FT-IR spectroscopic studies of hydrogen bonds in cholic acid, two-dimensional FT-IR spectroscopy was applied to enhance our understanding of the hydrogen bonds of cholic acid. Fine spectral structures were revealed by asynchronous 2D FT-IR spectra. The co-relationship among various bands was discussed according to the synchronous 2D FT-IR spectrum.展开更多
Equilibrium photoproduct of 7r-cyclopentadienyliron dicarbonyl dimer [CpFe（CO）2]2 in non- polar solvent carbon tetrachloride （CC14） is investigated using time-resolved 2D IR spec- troscopy. One of the several poss...Equilibrium photoproduct of 7r-cyclopentadienyliron dicarbonyl dimer [CpFe（CO）2]2 in non- polar solvent carbon tetrachloride （CC14） is investigated using time-resolved 2D IR spec- troscopy. One of the several possible visible-light-driven photoreaction pathways is confirmed and the product is found to contain a di-carbonyl group that exhibits quantum beating be- tween two equivalent transitions in time-resolved 2D IR spectra, which turns out to be the anti-symmetric and symmetric stretching of the terminal carbonyl stretching modes of CpFe（CO）2C1. This is the main product and its reaction pathway involves radical formation, followed by chloride addition. Quantum-chemistry computations support these experimental results. Our results indicate that 2D IR method can be used to identify in situ structures and dynamics of chemical species involved in condensed-phase chemical reactions.展开更多
文摘采用傅里叶变换红外(FT-IR)光谱法研究了二聚脂肪酸二异氰酸酯(DDI)/端羟基聚丁二烯(HTPB)体系的固化反应动力学,并与异佛尔酮二异氰酸酯(IPDI)/HTPB体系进行了比较。初步探索了DDI在HTPB推进剂中的应用。结果表明,DDI/HTPB体系的固化反应为二级反应,表观活化能为37.02 k J·mol-1,相比IPDI/HTPB体系降低了3.5 k J·mol-1,说明DDI的反应活性稍高于IPDI,反应活性适中,可作为低毒固化剂应用于HTPB推进剂中。DDI/HTPB体系推进剂具有较好的常温力学性能,抗拉强度为0.85 MPa时,最大伸长率为44.1%,可基本满足推进剂的常温力学性能要求。
基金The Project was supported by State Key Project of Basic Research MOST G1998061307 the National Natural Science Foundation of China (NSFC+8 种基金 grant No. 59733060 59873030 59953001 59903008 29671002 39730160 20023005 29901002) and Major Proj
文摘Based on cryogenic FT-IR spectroscopic studies of hydrogen bonds in cholic acid, two-dimensional FT-IR spectroscopy was applied to enhance our understanding of the hydrogen bonds of cholic acid. Fine spectral structures were revealed by asynchronous 2D FT-IR spectra. The co-relationship among various bands was discussed according to the synchronous 2D FT-IR spectrum.
文摘Equilibrium photoproduct of 7r-cyclopentadienyliron dicarbonyl dimer [CpFe（CO）2]2 in non- polar solvent carbon tetrachloride （CC14） is investigated using time-resolved 2D IR spec- troscopy. One of the several possible visible-light-driven photoreaction pathways is confirmed and the product is found to contain a di-carbonyl group that exhibits quantum beating be- tween two equivalent transitions in time-resolved 2D IR spectra, which turns out to be the anti-symmetric and symmetric stretching of the terminal carbonyl stretching modes of CpFe（CO）2C1. This is the main product and its reaction pathway involves radical formation, followed by chloride addition. Quantum-chemistry computations support these experimental results. Our results indicate that 2D IR method can be used to identify in situ structures and dynamics of chemical species involved in condensed-phase chemical reactions.
