Fracture surface morphology of poly[bis(trifluoroethoxy)phosphazene]

Poly[bis(trifluoroethoxy)phosphazene] (PBFP) films were prepared from tetrahydrofuran solution. Fracture surface morphology was studied by scanning electron microscopy. Two morphologies associated with heat treatment have been established: (a) cospherically grown aggregates are obtained in solution-cast films and films heated through the T(1) transition; (b) aggregates of irregular shaped crystalline platelets obtained after melting and crystallization. Ion etching was also applied to the fracture surface in order to clarify the morphological and structural features. The striations originally associated with the [c] axis direction of PBFP crystals can be accentuated on the fracture surface of original as-cast spherulitic films by employing this technique. The texture of the fracture surface after etching is compared with that obtained for an oriented fibre made from this polymer. From this comparison it can be concluded that the [c] axis direction is perpendicular to the spherulite radius. Furthermore the morphology is analogous in many respects to that of Kevlar.     

Crystal structure of poly[bis(3,4-dimethylphenoxy)phosphazene]

The crystal structure and chain conformation of poly[bis(3,4-dimethylphenoxy)phosphazene] — PB (dMe) PP — have been studied by X-ray diffraction techniques. The unit cell of this polymer shows an orthorhombic form with the crystallographic parameters a=2.05, b=1.49, c (chain axis)=0.998 nm. Its space group is determined as Pbcn-D _2h ¹⁴ where the molecular chains are located at the centre and each corner of the unit cell, which contains eight monomeric units; these molecular chains possibly have a — (trans ₃ cis)₂-conformation. The R factor calculated from the final crystal structure was estimated as 16.9%. As with other types of polyorganophosphazenes, the thermotropic transformation in PB (dMe) PP takes place from the three-dimensionally ordered state to its two-dimensional psuedohexagonal form (a _h = 1.49 nm), accompanied by a latent heat change at 96 °C.     

Construction of new iodide selective electrodes based on bis(trans-cinnamaldehyde)1,3-propanediimine(L) zinc(II) chloride [ZnLCl2] and bis(trans-cinnamaldehyde) 1,3-propanediimine(L) cadmium(II) chloride [CdLCl2]

New plasticized PVC membranes iodide selective electrodes have been prepared by incorporating bis(trans-cinnamaldehyde)1,3-propanediimine zinc(II) chloride [ZnLCl2] and bis(trans-cinnamaldehyde) 1,3-propandiimine cadmium(II) chloride [CdLCl2] on the surface of graphite disk electrodes. At optimum value of variables the proposed electrodes have selective response to iodide with respect to a number of inorganic and organic anions with near-Nernstian slopes of − 60 ± 1.9 and − 58.5 ± 1.9 mV/decade of iodide concentration over the range 1.0 × 10^− 6-1.0 × 10^− 1 M with detection limits of 4.0 × 10^− 7 and 3.0 × 10^− 7 M for the electrodes based on [ZnLCl₂] and [CdLCl₂], respectively. The electrodes based on both ionophores have response times of about (6 s), with stable reproducible response during 2 months, while their responses is independent of pH over the range 2.5-10.5. The proposed electrodes successfully have been applied for evaluation of iodide ion content in real samples with complicated matrices including water and pharmaceutical samples.     

三氟乙氧基取代聚磷腈纳米纤维的合成

基于磷腈三聚体(HCCP)的开环聚合和亲核取代合成了三氟乙氧基取代聚磷腈(PTFEP)。并对其进行红外光谱(FT-IR)、凝胶渗透光谱(GPC)、核磁共振磷谱(31P-NMR)、差示扫描量热(DSC)分析。以高压静电纺丝法制备了PTFEP纳米纤维,通过扫描电镜对其微观结构进行了观测,测定了其接触角。     

双酚A型聚芳醚酮的合成与表征

以双酚A和4,4'-二氟二苯酮为原料,采用新的合成工艺合成双酚A型聚芳醚嗣,通过红外光谱(FT-IR)、核磁共振(<'1>H-NMR)及差示扫描量热(DSC)等分析手段对聚合物的结构和性能进行了表征和研究.结果表明,含成的双酚A型聚芳醚酮具有良好的耐热性能,其玻璃化转变温度为152.8℃,氮气中5%热失重温度为509....     

聚甲基丙烯酸-N,N-二甲氨基乙酯中空纤维复合纳滤膜的制备与性能表征

以聚甲基丙烯酸-N,N-二甲氨基乙酯(PDM)作为交联预聚物,利用双苄基试剂在聚砜中空纤维超滤膜表面进行季铵化反应(界面聚合),制得荷正电复合中空纤维复合纳滤膜.研究了PDM浓度、外加碱、溶剂、交联剂和交联温度等制备条件的影响.所制备的中空纤维纳滤膜对2g/L MgSO4的截留率≥98%,通量19.5L/(m2·h),界面聚合时间为3.5h.     

Low temperature synthesis of a self-assembling composite: hydroxyapatite-poly[bis(sodium carboxylatophenoxy)phosphazene]

The present study was undertaken to investigate the low temperature formation of a hydroxyapatite-polyphosphazene polymer composite likely to be biocompatible. The temperature range studied (25 to 60°C) was selected to bracket physiological temperatures. The composite precursors consisted of CaHPO₄·2H₂O, Ca₄(PO₄)₂O, and poly[bis(sodium carboxylatophenoxy)phosphazene]. The results indicate that a synergistic relationship exists in the formation of a polyphosphazene network and hydroxyapatite (HAp) matrix phase during composite synthesis. Calcium from the HAp precursors participates in the formation of a Ca crosslinked polymeric network which influences the rate of HAp formation and its morphology. The mechanistic paths taken during composite formation were followed by determining variations in the concentration of species in solution (at physiological temperature), rates of heat evolution, and microstructural development. These analyses indicate that the polymer controls the kinetics of hydroxyapatite formation and the composite microstructure. Low reaction temperatures and a high proportion of polymer facilitate the formation of a highly interconnected composite. The presence of the polyphosphazene allows a metastable calcium phosphate solution to persist for extended periods prior to the formation of hydroxyapatite. The degree of supersaturation and the length of the induction period increase with an increase in polyphosphazene content. The temperature dependence of these induction periods obeyed an Arrhenius relationship.     

Mechanochromic luminescence of 4-[bis(4-methylphenyl)amino]benzaldehyde

The title compound was found to exhibit mechanochromic luminescence; the fluorescent color of the crystalline powder was changed from light blue to greenish yellow by grinding and then returned to the original by keeping at room temperature. The phenomenon was suggested to be due to formation of the supercooled liquid state of the material by grinding and following recrystallization.     

聚乙烯咔唑侧基含偶氮对硝基苯非线性光生色基团的合成及表征

研究了一种可作为聚合物类光折变材料中半功能型的基体材料——聚乙烯侧基含偶氮对硝基苯。以聚乙烯咔唑和偶氮盐为原料,以十二烷基苯磺酸钠为相转移催化剂,通过后重氮偶合方法,制备出聚乙烯咔唑侧基含生色团偶氮对硝基苯。用IR、UV-v is、1H-NM R、GPC对聚合物偶合前后进行了分析和表征。IR、UV-v is、1H-NM R测试表明了偶氮苯已经接到咔唑环上。UV-v is结果表明偶合反应时间对聚合物的偶氮含量有很大的影响。GPC结果表明,聚合物与重氮盐偶合后,分子量增大。     

聚甲基三氟丙基硅氧烷合成的研究进展

聚甲基三氟丙基硅氧烷(PMTFPS)可通过1,3,5-三甲基-1,3,5-三(3′,3′,3′-三氟丙基)环三硅氧烷(D3F)的阴离子开环聚合制备。归纳总结了PMTFPS合成方法的最新研究进展,主要从聚合机理、工艺条件的研究进行了总结与分析;并对合成方法目前存在的问题和发展方向进行了展望。     

Phase diagrams of the ternary liquid systems [Ce(NO3)3(TBP)3]-C10H22-[UO2(NO3)2(TBP)2] and [Ce(NO3)3(TBP)3]-C10H22-[Th(NO3)4(TBP)2] and of the quaternary liquid system [Ce(NO3)3(TBP)3]-C10H22-[UO2(NO3)2(TBP)2]-[Th(NO3)4(TBP)2]

The phase diagrams of the ternary liquid systems [Ce(NO₃)₃(TBP)₃]-C₁₀H₂₂-[UO₂(NO₃)₂(TBP)₂] and [Ce(NO₃)₃(TBP)₃]-C₁₀H₂₂-[Th(NO₃)₄(TBP)₂] and of the quaternary liquid system [Ce(NO₃)₃(TBP)₃]-C₁₀H₂₂-[UO₂(NO₃)₂(TBP)₂]-[Th(NO₃)₄(TBP)₂] at T = 298.15 K are constructed. The phase diagrams are characterized by areas of homogeneous solutions and of two-phase liquid systems (systems with phase separation), with one phase (I) enriched in [Ce(NO₃)₃(TBP)₃], [Th(NO₃)₄(TBP)₂], and [UO₂(NO₃)₂(TBP)₂], and the other phase (II), in C₁₀H₂₂. Using the data on the mutual solubility of the components in the systems under consideration and equations of the NRTL model, the parameters of intermolecular interactions and the excess Gibbs energies (G ^ex) were calculated for the binary, ternary, and quaternary systems. Passing from the ternary system [Ce(NO₃)₃(TBP)₃]-C₁₀H₂₂-[Th(NO₃)₄(TBP)₂] to the quaternary system [Ce(NO₃)₃(TBP)₃]-C₁₀H₂₂-[UO₂(NO₃)₂ (TBP)₂]-[Th(NO₃)₄(TBP)₂] does not appreciably affect the distribution of C₁₀H₂₂ between phases I and II, but leads to the redistribution of [Ce(NO₃)₃(TBP)₃] into phase II and of [Th(NO₃)₄(TBP)₂] into phase I.     

Crystal structures, thermal decompositions and sensitivity properties of [Cu(ethylenediamine)2(nitroformate)2] and [Cd(ethylenediamine)3](nitroformate)2

Two new coordination compounds [Cu(ethylenediamine)(2)(nitroformate)(2)] and [Cd(ethylenediamine)(3)](nitroformate)(2) were synthesized and characterized through elemental analysis, IR and UV spectra. Their crystal structures were determined through X-ray single crystal diffraction. The first compound crystallizes in the triclinic space group P1; the second one crystallizes in the orthorhombic space group Pbca. For the first compound, central Cu(II) ion is hexa-coordinated with two ethylenediamine ligand molecules and two nitroformate anions to form the centrosymmetric octahedral structure. For the second one, central Cd(II) ion is hexa-coordinated with three ethylenediamine ligand molecules to form the slightly distorted octahedra. Through hydrogen bonds, molecules are linked together to form the three-dimensional packing diagrams. Thermal decomposition mechanisms of these two compounds were predicted through DSC, TG-DTG and FTIR analyses. In addition, the impact sensitivity, friction sensitivity and flame sensitivity were measured. All observed properties show that the first one has high energy, good thermal stability and moderate flame sensitivity.