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1984 Volume 1 Issue 3
1984, 1(3): 1-10
Abstract:
A brief review of the recent progress in conductive polymers is prese-nted in this paper with the emphasis on those consisted of organic conjuga-ted system. The most interesting and perspective work in this field as the author considered lies in taking exhaustive study on the conduction process and the relation between their structure and properties to attain the possible practical application.
A brief review of the recent progress in conductive polymers is prese-nted in this paper with the emphasis on those consisted of organic conjuga-ted system. The most interesting and perspective work in this field as the author considered lies in taking exhaustive study on the conduction process and the relation between their structure and properties to attain the possible practical application.
1984, 1(3): 11-18
Abstract:
A new binary rare earth chloride catalyst composed of NdCl3·2Phen(Phen=1, 10-phenanthroline) and HAl (i-Bu)2 for stereospecific polymerization of butadiene has been presented. In contrast to other type of rare earth chloride catalysts the present system is characterized by its ability to control the molecular weight of the product and its specific mode of formation. The general rule of butadiene polymerization with the cata-lyst was studied. It was found that HAl(i-Bu)2 is mainly the chain transfer agent in the reaction and the HAl (i-Bu)2/monomer ratio is a key parameter controlling the molecular weight of polybutadiene obtained.The possible role of the phen molecule in molecular weight controlling has been discussed.
A new binary rare earth chloride catalyst composed of NdCl3·2Phen(Phen=1, 10-phenanthroline) and HAl (i-Bu)2 for stereospecific polymerization of butadiene has been presented. In contrast to other type of rare earth chloride catalysts the present system is characterized by its ability to control the molecular weight of the product and its specific mode of formation. The general rule of butadiene polymerization with the cata-lyst was studied. It was found that HAl(i-Bu)2 is mainly the chain transfer agent in the reaction and the HAl (i-Bu)2/monomer ratio is a key parameter controlling the molecular weight of polybutadiene obtained.The possible role of the phen molecule in molecular weight controlling has been discussed.
1984, 1(3): 19-24
Abstract:
By means of microscopy, scanning electron microscopy, and infrared analysis, the course of formation of the ternary mixed blend composed of PP-g-P(MA-co——VAc) and P(MA-co-VAc) during heterogeneous graft copoly-merization of MA/VAc mixtures onto PP, the morphological structure of the grafting products and the effect of the P (MA-co-VAc) content on the crytallization behavior from melt in the presence of PP-g-P (MA-co-VAc) have been studied. The results show that the polymer blends, similar to metallic alloy, have a special composition under given conditions.
By means of microscopy, scanning electron microscopy, and infrared analysis, the course of formation of the ternary mixed blend composed of PP-g-P(MA-co——VAc) and P(MA-co-VAc) during heterogeneous graft copoly-merization of MA/VAc mixtures onto PP, the morphological structure of the grafting products and the effect of the P (MA-co-VAc) content on the crytallization behavior from melt in the presence of PP-g-P (MA-co-VAc) have been studied. The results show that the polymer blends, similar to metallic alloy, have a special composition under given conditions.
1984, 1(3): 25-29
Abstract:
Samples of bubble films upon gadolinium-gallium garnet substract were dissolved in conc. nitric and 18N sulfuric acids mixture (2: 1). The re-sulting solution was used for following determinations.(a) Chelometric micro titration of iron with EDTA using N-benzoyl-N-phenylhydroxylamine as indicator. Iron was also determined spectrophotometrically with o-phena-nthroline. (b) Calcium was determined chelometrically with cyclohexanedia-minetetraacetic acid (CYDTA), after removal of gallium, germanium and iron by extraction with butylacetate from 7N HCl medium and titration of total rare earths with EDTA at pH5, using xylenol orange as indicator.The latter should be destroyed by saturated bromine water before calcium titra-tion. (c) Germanium was determined spectrophotometrically with fluorone-cetyltrimethylammonium bromide (CTAB) at 506 nm. (d) The separation and determination of gadolinium, lutetium, samarium and yttrium: the rare earths were extracted with 0.5% 1-phenyl-3-methyl-4-benzoylpyrazol-5-one in benzene and then separated by reversed-phase column chromato-graphy. The column was filled with silanized silicagel (100-00mesh) impregnated with 2-ethyl-hexylphosphoric acid mono-2-ethylhexylester and the 3 RE were eluted subsequently by HCl of different concentration. They were finally determined spectrophotometrically with arsenazo Ⅲ. The results from two film samples were. given in the paper for illustration.
Samples of bubble films upon gadolinium-gallium garnet substract were dissolved in conc. nitric and 18N sulfuric acids mixture (2: 1). The re-sulting solution was used for following determinations.(a) Chelometric micro titration of iron with EDTA using N-benzoyl-N-phenylhydroxylamine as indicator. Iron was also determined spectrophotometrically with o-phena-nthroline. (b) Calcium was determined chelometrically with cyclohexanedia-minetetraacetic acid (CYDTA), after removal of gallium, germanium and iron by extraction with butylacetate from 7N HCl medium and titration of total rare earths with EDTA at pH5, using xylenol orange as indicator.The latter should be destroyed by saturated bromine water before calcium titra-tion. (c) Germanium was determined spectrophotometrically with fluorone-cetyltrimethylammonium bromide (CTAB) at 506 nm. (d) The separation and determination of gadolinium, lutetium, samarium and yttrium: the rare earths were extracted with 0.5% 1-phenyl-3-methyl-4-benzoylpyrazol-5-one in benzene and then separated by reversed-phase column chromato-graphy. The column was filled with silanized silicagel (100-00mesh) impregnated with 2-ethyl-hexylphosphoric acid mono-2-ethylhexylester and the 3 RE were eluted subsequently by HCl of different concentration. They were finally determined spectrophotometrically with arsenazo Ⅲ. The results from two film samples were. given in the paper for illustration.
1984, 1(3): 30-33
Abstract:
Two new azoxybisbenzocrown ethers were synthesized. Preparative method of azo-xybisbenzo-15-crown-5 has been improved with the yield up to 65.3%. It was obser-ved that the degree of dissociation of electron-transfer agent plays an important rolein product yield. The results were interpreted in terms of solvent polarity.Photo-andthermo-isomerization of azoxybisbenzocrown ethers have been studied preliminarily.
Two new azoxybisbenzocrown ethers were synthesized. Preparative method of azo-xybisbenzo-15-crown-5 has been improved with the yield up to 65.3%. It was obser-ved that the degree of dissociation of electron-transfer agent plays an important rolein product yield. The results were interpreted in terms of solvent polarity.Photo-andthermo-isomerization of azoxybisbenzocrown ethers have been studied preliminarily.
1984, 1(3): 34-40
Abstract:
The GPC coupling with an automatic capilary viscometer and its applica-tion to polymer characterization were described in this paper with particular emphasis on the effects of temperature controlling and wall flow during the measurement. In order to calculate the intrinsic viscosity the following relation has been used:<[η]>=ΣWi[ηi] where [ηi] is the viscosity of eluted volume Vi.
The GPC coupling with an automatic capilary viscometer and its applica-tion to polymer characterization were described in this paper with particular emphasis on the effects of temperature controlling and wall flow during the measurement. In order to calculate the intrinsic viscosity the following relation has been used:<[η]>=ΣWi[ηi] where [ηi] is the viscosity of eluted volume Vi.
1984, 1(3): 41-46
Abstract:
A highly active supported catalyst (TiCl4-PCl3)/MgC12-AlEt3 for ethylene-propylene copolymerization is reported. Ethylene-propylene copolymer with low molecular weight and narrow molecular weight distribution has been obtained through the addition of PCl3 ligand in the catalyst system and the hydrogen regulation in the course of reaction. The copolymer is sui-table for viscosity index improver for lubricating oil, having rather good overall properties in respect of viscosity index, thickness, low temperature viscosity, and stabilities against shearing, oxidation. heat etc..
A highly active supported catalyst (TiCl4-PCl3)/MgC12-AlEt3 for ethylene-propylene copolymerization is reported. Ethylene-propylene copolymer with low molecular weight and narrow molecular weight distribution has been obtained through the addition of PCl3 ligand in the catalyst system and the hydrogen regulation in the course of reaction. The copolymer is sui-table for viscosity index improver for lubricating oil, having rather good overall properties in respect of viscosity index, thickness, low temperature viscosity, and stabilities against shearing, oxidation. heat etc..
1984, 1(3): 47-50
Abstract:
The crystal of potassium europium metaphosphate KEu(PO3)4 belongs to the monoclinic space group P21 with unit cell parameters a=7.932(4)Å,b=8.375(1)Å, c=7.261(3)Å, β=92.05(4)°, V=482.0Å3, Z=2. The intensities of 979 independent reflections were collected by the PW-1100 four-circle diffractometer. The structure was solved by heavy-atom method and the final R=0.084 after refining by full-matrix least-squares method.The basic structure units are helical ribbons, (PO3)n, formed by cornershar-ing tetrahedra of PO4. The coordination of the europium anion by oxygen atoms is eight-fold with the geometry of dodecahedra. The shortest Eu-Eu distance is 6.93Å.
The crystal of potassium europium metaphosphate KEu(PO3)4 belongs to the monoclinic space group P21 with unit cell parameters a=7.932(4)Å,b=8.375(1)Å, c=7.261(3)Å, β=92.05(4)°, V=482.0Å3, Z=2. The intensities of 979 independent reflections were collected by the PW-1100 four-circle diffractometer. The structure was solved by heavy-atom method and the final R=0.084 after refining by full-matrix least-squares method.The basic structure units are helical ribbons, (PO3)n, formed by cornershar-ing tetrahedra of PO4. The coordination of the europium anion by oxygen atoms is eight-fold with the geometry of dodecahedra. The shortest Eu-Eu distance is 6.93Å.
1984, 1(3): 51-56
Abstract:
It has been shown that cis-1,4-polybutadiene obtained by rare-earth ca-talyst (Ln-PB) possesses a cis-1,4-content higher than 98%,and can be cry-stallized rapidly at low temperature. This paper presents our study on the relation of molecular weight and temperature with the crystallization beha-viour of Ln-PB with dilatometer and electron microscope. A set of crystallization rate curves of Ln-PB is given in this paper. It is seen that the minimum rate of crystallization occurs in the range of < M >η=4.6-6.7×105, while the maximum rate in the range of < M >η=3.0-3.8×106.The result has been interpreted in terms of the nucleus theory of crystallization. It is also shown that, for Ln-PB, there is a transition at about -20℃ from regime Ⅰ to regime Ⅱ as crystallization temperature decreases. The interfacial free energy of Ln-PB, σe, is to be about 17erg/cm2, when < M >η<106, which increases with increasing molecular weight when < M >η>106.
It has been shown that cis-1,4-polybutadiene obtained by rare-earth ca-talyst (Ln-PB) possesses a cis-1,4-content higher than 98%,and can be cry-stallized rapidly at low temperature. This paper presents our study on the relation of molecular weight and temperature with the crystallization beha-viour of Ln-PB with dilatometer and electron microscope. A set of crystallization rate curves of Ln-PB is given in this paper. It is seen that the minimum rate of crystallization occurs in the range of < M >η=4.6-6.7×105, while the maximum rate in the range of < M >η=3.0-3.8×106.The result has been interpreted in terms of the nucleus theory of crystallization. It is also shown that, for Ln-PB, there is a transition at about -20℃ from regime Ⅰ to regime Ⅱ as crystallization temperature decreases. The interfacial free energy of Ln-PB, σe, is to be about 17erg/cm2, when < M >η<106, which increases with increasing molecular weight when < M >η>106.
1984, 1(3): 57-62
Abstract:
From the interfacial properties of the titled systems,it may be concluded that HEH(EHP) is adsorbed at the interface in the form of single molecule.The adsorability depends on the temperature and the nature of diluents.It is shown that the greater the difference in polarity between two phases, the stronger the interfacial adsorbabilityis, and the higher the temperature, the weaker the adsorbability is. The relation between the adsorptive properties of HEH(EHP) and its extractability has also been discussed in this paper.
From the interfacial properties of the titled systems,it may be concluded that HEH(EHP) is adsorbed at the interface in the form of single molecule.The adsorability depends on the temperature and the nature of diluents.It is shown that the greater the difference in polarity between two phases, the stronger the interfacial adsorbabilityis, and the higher the temperature, the weaker the adsorbability is. The relation between the adsorptive properties of HEH(EHP) and its extractability has also been discussed in this paper.
1984, 1(3): 63-67
Abstract:
The 13C-NMR spectrum of the alternating copolymer of butadiene (BD) with methyl methacrylate (MMA) has been studied. The results indicate that the degree of alternation approches to 99.2% and the contents of trans-1,4-,cis-1, 4-and 1, 2-BD in the alternating structure units are 97.6%, 1.3% and 1.1%, respectively. It has also been proved by the 13C-NMR spectra that every block of the block polymer, poly[(ST-a-MA)-b-(BD-a-MMA)-b-(ST-a-MA)] has alterna-ting structure as well.
The 13C-NMR spectrum of the alternating copolymer of butadiene (BD) with methyl methacrylate (MMA) has been studied. The results indicate that the degree of alternation approches to 99.2% and the contents of trans-1,4-,cis-1, 4-and 1, 2-BD in the alternating structure units are 97.6%, 1.3% and 1.1%, respectively. It has also been proved by the 13C-NMR spectra that every block of the block polymer, poly[(ST-a-MA)-b-(BD-a-MMA)-b-(ST-a-MA)] has alterna-ting structure as well.
1984, 1(3): 68-71
Abstract:
