RELATIONSHIP BETWEEN INTERFACIAL REACTION AND BULK PROPERTIES OF PET/FUNCTIONALIZED HDPE BLENDS

High-density polyethylene (HDPE) grafted with blocked isocyanate group (BHI) was blended with polyethylene terephthalate (PET) to observe the relationship between interfacial chemical reaction and bulk properties of the blends. BHI was prepared by reacting ?-caprolactam (CPL) with hydroxyethyl methacrylate-isophorone diisocyanate (HI). Atomic force microscopy (AFM) analysis was used to confirm the interfacial chemical reaction of isocyanate (NCO) groups in the functionalized HDPE (HDPE-g-BHI) with carboxylic acid and hydroxyl end groups in PET after annealing. Interfacial topologies and mean roughness were observed. Morphological changes of the blends were observed by scanning electron microscopy (SEM) photographs. Measurements of elongation property and dynamic mechanical analysis (DMA) of the blends were also done.     

THE SOLID STATE REACTIONS AND TRANSITIONS IN HIGH POLYMERIC SYSTEMS Ⅲ. THE BULK CRYSTALLIZATION OF LANTHANIDECATALYTICALLY POLYMERIZED POLYDIENES

For the mechanism of isothermal bulk crystallization of high polymers, beside the nucleation and growth steps, the unimpingement of growing crystal aggregates should be taken into account for the modification of the Avrami equation. Starting from Poisson distribution function of growing crystal aggregates, the probability of the unimpinging ones should be P(0)+P(1), then the Q-modified Avrami equation thus derived can be expressed aswhere V0 represents the volume fraction of crystal aggregates at crystallization time t at a given temperature, while the exponent n on t relates to the mode of nucleation and growth, and K_q is the corresponding shape factor. This Q-modified one is verified satisfactory by the isothermal bulk crystallization of lanthanidecatalytically polymerized polybutadiene (Ln-PB), polyisoprene (Ln-PIR) and their copolymers (LnPB/IR). Furthermore, the proposed mechanism is well identified by the change of morphological state during the course of crystallization of the corresponding east film of Ln-PB TR (92/8) at-60°(Fig. 1).Upon examination of the influence of the number of entanglement on crystallization rate, it reveals the existence of two stages of entanglementation, the primary and the secondary ones (Fig. 19)The equation for dependence of molecular weight and entanglement on bulk crystallization rate has been derived as Eq. 13 or 18 for Ln-PB, and verified by the experimental rate data of well fractionated Ln-PB samples crystallized at -9.1 to -15℃(Fig.20).     

固相配位化学反应研究——ⅩⅩⅩⅤ 热分解合成Co-N_2配合物及其加氢性质研究

1965年Allen报道了第一个分子氮配合物的合成以来,迄今已合成了分子氮配合物三百余个,而且几乎所有稳定分子氮配合物的合成都在溶液中进行。本文报道通过K_3[Co(CN)_5N_3]的固相热分解反应获得Co-N_2配合物,并且研究发现该分子氮配合物在氢气氛中于220℃加氢生成氨。配合物K_3[Co(CN)_5N_3]·2H_2O按文献方法合成。     

固相配位化学反应研究——ⅩⅩⅩⅤ 热分解合成Co-N2配合物及其加氢性质研究

This paper reports the thermodecomposition of K₃[Co(CN)₅N₃]·2H₂O both in helium and hydrogen atmosphere with gas chromatography. The product in helium at 250℃ have been studied by IR, Raman, ESR and XRD. The dinitrogen complexes of K₃Co(CN)₅N₂ and K₆[Co₂(CN)₁₀N₂] have been identified, and those dinitrogen complexes could be hydrogenized under hydrogen atmosphere to obtain ammonia.     

STUDY OF THE MOLECULAR MOTION AND COMPATIBILITY IN AB-CROSSLINKED POLYMER BASED ON POLYURETHANE AND POLYSTYRENE-co-ACRYLIC ACID BY SOLID STATE HIGH RESOLUTION NMR

The ~(13)C T_(1s) of --CH_3 side group in PPU/P (St-co-AA), AB-crosslinked polymers (i. e.ABCP) was studied by using high resolution solid state NMR. The rotation motion of --CH_3 sidegroup in PPU was analyzed by means of the average spectral density functions of internal rota-tion. The results showed that the rotation of the --CH_3 side group is related closely to the com-patibility between the two components. The compatibility was studied by analyzing the protonspin-lattice relaxation in rotating frame, spin-spin relaxation and spin-diffusion. The resultsshowed that the hydrogen bonds between the components play a major role in determining thecompatibility. Through spin diffusion studying, the soft phase domain size was calculated. Bystudying proton spin-spin relaxation, the content of each component in each phase and that ofeach phase in the samples can be obtained. The result shows that the content of interphase is related closely to the compatibility.     

OCTAHEDRAL METAL CARBONYLS. XXVIII.1 KINETICS AND MECHANISM OF OXIDATIVE ELIMINATION REACTIONS OF SUBSTITUTED GROUP VI-B METAL CARBONYLS WITH TIN- AND GERMANIUM-CONTAINING OXIDIZING AGENTS

Abstract

The kinetics and mechanism of reactions of (2,2′-dipyridyl)W(CO)₄ with SnCl₄, (C₆H₅)SnCl₃, (n-C₄H₉)SnCl₃ and (C₆H₅)₂SnCl₂, and of (o-phenanthroline)Mo(CO)₄ with GeI₄ have been investigated employing stopped flow and conventional kinetic techniques. The oxidizing agent-dependent rate laws are encompassed in a mechanism which involves reversible addition of two successive molecules of the oxidant to the substrate, followed by other, rapid, steps. For the reaction of (C₆H₅SnCl₂ with (dipy)W(CO)₄ at 95–115°, a parallel reaction path probably involving rate-determining dissociation of CO was also observed. Rates were found to be very sensitive to the nature of the substituents bonded to the Group IV-A metal, being greatest for electron-withdrawing substituents. Different rate laws were observed for reactions which yielded products of different stereochemistries.     

STUDIES OF A.C. CONDUCTIVITY OF POLY(VINYL BORATE) AND ITS CALCIUM DERIVATIVE IN SOLID STATE

An attempt has been made in the present work to prepare poly(vinyl borate),PVBO and its calcium derivative by homogeneous esterification of PVA with boric acid in non-aqueous medium in the presence of a catalyst ethyl nitrate dimethyl sulfoxide.The compounds were characterized by IR and ~1H-NMR spectra.Conductivities were determined from 30℃to 90℃in solid state within a frequency range of 42 Hz to 100 kHz.The compounds so formed showed ionic conductivity and their conductivities were dependent on frequen...     

固相配位化学反应研究——ⅩⅩⅩⅩⅠ.[Co(NH3)5(H2O)]Br3,[Cr(NH3)5(H2O)](NO3)3与无机盐KY(Y=Cl,Br,Ⅰ)的固相反应动力学研究

本文主要用气相色谱逸出气体分析方法,借助于红外、紫外可见漫反射谱等手段研究了[Co(NH₃)₅(H₂O)]Br₃、[Cr(NH₃)₅(H₂O)](NO₃)₃与无机盐KY(Y=Cl,Br,Ⅰ)的固相反应,计算了失水与失氨的动力学参数,发现第一步反应失水生成一取代中间产物,其活化能与外加阴离子无关,为S_N