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《高分子科学杂志,A辑:纯化学与应用化学》2013,50(10):1141-1157
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. 相似文献
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QIAN Baogong 《高分子科学》1988,(2):97-116
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). 相似文献
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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 总被引:1,自引:0,他引:1
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. 相似文献
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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. 相似文献
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《Journal of Coordination Chemistry》2012,65(4):271-275
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. 相似文献
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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... 相似文献
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