首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到8条相似文献,搜索用时 0 毫秒
1.
A phosphorus-containing monomer(10-oxo-10-hydro-9-oxa-10λ~5-phosphaphenanthrene-10-yl)-methyl acrylate(M_1) was copolymerized with styrene to give a potential flame retardant copolymer of high thermal stability.The structures of monomer and copolymer were characterized by FT-IR and ~1H NMR measurements.The reactivity ratios for free-radical of the monomer(M_1) and styrene(M_2) were studied.The calculated results are as follows:r_1=0.225,r_2=0.503;Q_1=0.413,e_1= 0.476;azeotropic point = 0.37.TGA and DTG c...  相似文献   

2.
3.
唐涛 《高分子科学》2014,32(3):333-349
Effects of branches on the crystallization kinetics of polypropylene-g-polystyrene(PP-g-PS) and polypropylene-gpoly(n-butyl acrylate)(PP-g-PnBA) graft copolymers with well-defined molecular structures were systematically investigated by DSC.The Avrami equation was used to analyze the isothermal crystallization process,while the analysis of nonisothermal crystallization process was based on the Jeziorny-modified Avrami model and Mo model.The kinetics results of isothermal and nonisothermal crystallization verified the peculiar effects of branches on the crystallization process of PP backbones in PP-g-PS and PP-g-PnBA graft copolymers:on one hand,the interaction between branches(π-π interaction between PS branches,or dipole-dipole interaction between PnBA branches) restrained the mobility and reptation ability of the PP backbones,which hindered the crystallization process;on the other hand,the heterogeneous nucleation effect resulting from the branched structure and fluctuation-assisted nucleation mechanism(caused by microphase separation between the PS or PnBA rich phase and the PP rich phase) became more pronounced with increasing branch length,which facilitated the crystallization process.  相似文献   

4.
A new metal-organic coordination polymer [Cd(5-hip)(phen)]n·nH2O 1 has been hydro- ermally synthesized and characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. The crystal of the complex crystallizes in monoclinic, space group P2/n with a = 8.8071(17), b =12.386(2), c = 16.981(3) A, β = 100.182(2)°, V = 1823.2(6) A^3, Mr=. 490.73, Dc =1.788 g/cm^3,μ(MoKa) = 1.240 mm^-1, F(000) = 976, Z= 4, the final R = 0.0458 and wR = 0.1373 for 2864 observed reflections (I 〉 2σ(I)). The Cd atoms are coordinated by two N atoms from the phen ligands and four O atoms from 5-hydroxyisophthalate ligands in a highly distorted octahedral geometry.  相似文献   

5.
Two new Ni( Ⅱ) coordination polymers, {[Ni(tbip)(bipy)(H2O)]-0.5H2O}n 1 and [Ni(tbip)(phen)(H2O)]n 2 (Hatbip = 5-tert-butyl isophthalic acid, bipy = 2,2'-bipyridine, phen = 1,10-phenanthroline), have been synthesized under hydrothermal conditions and characterized by elemental analysis, X-ray diffraction, and IR spectroscopy. In the two polymers, H2tbip acts as a tridentate ligand. Compound 1 has a tbip bridged 1-D linear chain which is extended by hydrogen bonds into a 1-D double chain, while compound 2 exhibits a 1-D zigzag chain.  相似文献   

6.
A novel organic polycarboxylate N-cyclohexylaziridines-2R,3S-dicarboxylic acid was synthesized and reacted with Ni2(OH)2CO3.As a result,a coordination polymer was obtained.It crystallizes in orthorhombic,space group Pbca with a = 8.6325(10),b = 10.5414(13),c = 27.644(3) ,Z = 4,V = 2515.5(5) 3,C20H34N2Ni2O12,Mr = 611.91,Dc = 1.616 g/cm3,μ = 1.562 mm-1,F(000) = 1280,the final R = 0.0320 and wR = 0.0677 for 2854 independent reflections with Rint = 0.0390.Crystal structure shows that the coordination environment around the Ni(Ⅱ) ion can be described as a slightly distorted octahedron.The ligands act as a bridge through the carboxyl O atoms and join the Ni atoms into an infinite 1D chain structure.The 1D chain forms a 2D network through intermolecular O-H…O hydrogen bonds.The magnetic susceptibility measurements(2~300 K) agree with a weak antiferronmagnetic interaction between neighboring Ni ions in the chain.  相似文献   

7.
1INTRODUCTION The chemistry of molybdenum-sulfur compounds has attracted the attention from chemists,bioinor-ganic chemists and biochemists because Mo and S are important elements of metal enzymes especially N2-ase[1~6].Since the di-molybdenum(0)thiolate com-pound with a[Mo2S2]2?unit core and two-electron transfer character,[Et4N]2[Mo2(SR)2(CO)8](R=Ph,tBu),was synthesized by introducing thiolate ligands into Mo(CO)6[7],the chemistry of complexes conta-ining low valence molybdenum at…  相似文献   

8.
Novel cyclic esters (1R, 2R, 3R, 5S, 7S, 9R, 12R)-3-(t-butyldimethylsilyl)oxy-7-methoxymethyloxy-2, 10-dimethyl-12-oxatricyclo [7.2.1.0^5,12] dodecane were prepared when their precursor 1 was treated with SOC12/pyridine. A plausible mechanism was hypothesized.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号