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1986 Volume 3 Issue 2
1986, 3(2): 1-4
Abstract:
Block copolymers containing segments of polysulfone and polyhydroxyethers were synthesized by interaction of bisphenol A(Bis-A) with epichlorohydrin in the presence of dihydroxyl-terminated polysulfone oligomers with DMSO as solvent under alkaline condition. The block copolymers were characterized by infrared spectroscopy, dynamic mechanical behavior and their solubilities. In contrast to the simple physical blend,the polysulfone-polyhydroxyether block copolymers were transparent and displayed single glass transition temperature (Tg=130℃),while the blends of the homopolymers were opaque and displayed two glass transition temperatures(Tg1=95℃, Tg2=191℃). (Fig. 1 and Fig. 2)
Block copolymers containing segments of polysulfone and polyhydroxyethers were synthesized by interaction of bisphenol A(Bis-A) with epichlorohydrin in the presence of dihydroxyl-terminated polysulfone oligomers with DMSO as solvent under alkaline condition. The block copolymers were characterized by infrared spectroscopy, dynamic mechanical behavior and their solubilities. In contrast to the simple physical blend,the polysulfone-polyhydroxyether block copolymers were transparent and displayed single glass transition temperature (Tg=130℃),while the blends of the homopolymers were opaque and displayed two glass transition temperatures(Tg1=95℃, Tg2=191℃). (Fig. 1 and Fig. 2)
1986, 3(2): 5-10
Abstract:
In this paper a novel method is proposed for estimating number-average molecular weight from the intrinsic viscosity and GPC chromatogram of a sample for which the constants in Mark-Houwink equation is not known.The method was tested on seven samples which have very different value of molecular weight and molecular weight distribution.Results calculated by the method are in good agreement with those obtained using conventional method which requires constants of Mark-Houwik equation. The method is ijust approximate but fairly simple for number-average molecular weight determination
In this paper a novel method is proposed for estimating number-average molecular weight from the intrinsic viscosity and GPC chromatogram of a sample for which the constants in Mark-Houwink equation is not known.The method was tested on seven samples which have very different value of molecular weight and molecular weight distribution.Results calculated by the method are in good agreement with those obtained using conventional method which requires constants of Mark-Houwik equation. The method is ijust approximate but fairly simple for number-average molecular weight determination
1986, 3(2): 11-16
Abstract:
1H,17O and 35Cl NMR chemical shifts of rare earth aqueous solutions were studied.The hydration number and hydrate configuration determined were as follows:The hydration number of Pr, Nd ions is 9 and their hydrate configurations are tricapped trigonal prismatic. The hydration number of Tb, Dy, Ho, Er, Tm, Yb ions is 8 and their hydrate configurations are square antiprismatic. The hyperfine coupling constant between 17O and 4f electrons of rare earth ions was also calculated.
1H,17O and 35Cl NMR chemical shifts of rare earth aqueous solutions were studied.The hydration number and hydrate configuration determined were as follows:The hydration number of Pr, Nd ions is 9 and their hydrate configurations are tricapped trigonal prismatic. The hydration number of Tb, Dy, Ho, Er, Tm, Yb ions is 8 and their hydrate configurations are square antiprismatic. The hyperfine coupling constant between 17O and 4f electrons of rare earth ions was also calculated.
1986, 3(2): 17-22
Abstract:
The tritiated alcohol quench method was used for determining the tritium number average molecular weight [Mn]T of polybutadiene prepared wtih lanthanide catalysts.The change in [Mn]T Wtih conversion for different lanthanide catalysts was studied. It was found that for certain lanthanide catalytic systems the values of [Mn]T of polybutadiene were approximately equal to those obtained by using osmometry technique. It was shown that the tritium end group analysis could be used for determining Mn of polybutadiene prepared with lanthanide catalysts.
The tritiated alcohol quench method was used for determining the tritium number average molecular weight [Mn]T of polybutadiene prepared wtih lanthanide catalysts.The change in [Mn]T Wtih conversion for different lanthanide catalysts was studied. It was found that for certain lanthanide catalytic systems the values of [Mn]T of polybutadiene were approximately equal to those obtained by using osmometry technique. It was shown that the tritium end group analysis could be used for determining Mn of polybutadiene prepared with lanthanide catalysts.
1986, 3(2): 23-27
Abstract:
The orientation of PET films uniaxially or biaxially stretched with different draw rate has been studied by means of polarized IR spectroscopy. Comparision was given for films of almost the same value of density and trans conformation content. It was found that for uniaxially stretched specimens the degree of orientation of molecular chains with respect to the stretching direction was higher than that of the biaxially stretched ones,therefore a high value of the anisotropy of molecular orientation along the film plane eculd be revealcd.An evident plane orientation of molecular plane (benzene ring plane) with respect to the film plane was observed for biaxially stretched films, but a nearly random distribution of molecular plane was found for uniaxially stretched specimens. The influence of draw rate as used in this work on molecular orientation was found to be negligible.
The orientation of PET films uniaxially or biaxially stretched with different draw rate has been studied by means of polarized IR spectroscopy. Comparision was given for films of almost the same value of density and trans conformation content. It was found that for uniaxially stretched specimens the degree of orientation of molecular chains with respect to the stretching direction was higher than that of the biaxially stretched ones,therefore a high value of the anisotropy of molecular orientation along the film plane eculd be revealcd.An evident plane orientation of molecular plane (benzene ring plane) with respect to the film plane was observed for biaxially stretched films, but a nearly random distribution of molecular plane was found for uniaxially stretched specimens. The influence of draw rate as used in this work on molecular orientation was found to be negligible.
1986, 3(2): 28-32
Abstract:
Liquid carboxyl-terminated polychloroprene(CTCP) was synthesized by means of emulsion polymerization using cyclohexone peroxide(CHPO)-ferrous sulfate as redox initiator.During polymerization process,chloroprene and CHPO solution were added to the reaction mixture continually. The results of IR and NMR determination of CTCP indcate that chloroprene units are mainly of trans 1,4-structure and connecte each other in the head-to-tail form. Epoxy resin could be toughened by this liquid rubber in certain extent.
Liquid carboxyl-terminated polychloroprene(CTCP) was synthesized by means of emulsion polymerization using cyclohexone peroxide(CHPO)-ferrous sulfate as redox initiator.During polymerization process,chloroprene and CHPO solution were added to the reaction mixture continually. The results of IR and NMR determination of CTCP indcate that chloroprene units are mainly of trans 1,4-structure and connecte each other in the head-to-tail form. Epoxy resin could be toughened by this liquid rubber in certain extent.
1986, 3(2): 33-36
Abstract:
The influences of the contents of Sb,As and Ag in the Pb-alloy on its corrosive weight loss, mechanical properties and cyclic voltammograms have been systematically investigated and a proper alloy composition for anodic grid was obtained.Electron beam mieroprobe analysis of alloy samples showed that incorporating certain amount of Ag in the Pb-Sb alloy leads to the disappearance of the intercrystalline antimony rich phase.This would be responsible for the improvement of the corrosion-resistance of the alloy.
The influences of the contents of Sb,As and Ag in the Pb-alloy on its corrosive weight loss, mechanical properties and cyclic voltammograms have been systematically investigated and a proper alloy composition for anodic grid was obtained.Electron beam mieroprobe analysis of alloy samples showed that incorporating certain amount of Ag in the Pb-Sb alloy leads to the disappearance of the intercrystalline antimony rich phase.This would be responsible for the improvement of the corrosion-resistance of the alloy.
1986, 3(2): 37-41
Abstract:
The processes of thermal decomposition of HTPB are studied using thermal analysis method and infrared spectroscopy.The products from thermal splitting decomposition of HTPB are analysed by gas chromatography.The experimental results show that the whole courses of the thermal decomposition of HTPB can be divided into two stages.The former is related to the degradation and cross-linking of the weak-link bonds of the polymer,and the latter is considered to be the degradation caused by the breakage of the main chain of the polymer.The mechanism of thermal decomposition of HTPB proposed may eliminate the divergence of previous statements.
The processes of thermal decomposition of HTPB are studied using thermal analysis method and infrared spectroscopy.The products from thermal splitting decomposition of HTPB are analysed by gas chromatography.The experimental results show that the whole courses of the thermal decomposition of HTPB can be divided into two stages.The former is related to the degradation and cross-linking of the weak-link bonds of the polymer,and the latter is considered to be the degradation caused by the breakage of the main chain of the polymer.The mechanism of thermal decomposition of HTPB proposed may eliminate the divergence of previous statements.
1986, 3(2): 42-47
Abstract:
More stable prussian blue modified platinum electrodes which can underyo over one thousand cycles of potential sweep between +0.6V and +1.1V(Vs, SCE) have been made.A model of electron transfer during the electrochemical redox process of the PB film has been proposed. The effects of preparation conditions, film thickness and the pH value of supporting electrolyte solution on voltammetric behaviour of the electrode have been studied systemmatically.
More stable prussian blue modified platinum electrodes which can underyo over one thousand cycles of potential sweep between +0.6V and +1.1V(Vs, SCE) have been made.A model of electron transfer during the electrochemical redox process of the PB film has been proposed. The effects of preparation conditions, film thickness and the pH value of supporting electrolyte solution on voltammetric behaviour of the electrode have been studied systemmatically.
1986, 3(2): 48-52
Abstract:
It was shown in this paper that the work function of the rapidly deposited Cr layer was smaller than that of slowly deposited one with the average value of 3.99eV and an increased value of Voc up to 0.51-0.56V.The sheet resistance of Cr can then be decreased.Therefore,the Cu layer as well as the outer layer of Cr usually deposited for decreasing the sheet resistance of Cr and for preventing Cu from oxidation,respectively, can be saved.The conversion effecioncy of Cr-MIS solar cell is of 12%,based on the active area of 1.3cm2 at AM1.5 (100mW/cm2).
It was shown in this paper that the work function of the rapidly deposited Cr layer was smaller than that of slowly deposited one with the average value of 3.99eV and an increased value of Voc up to 0.51-0.56V.The sheet resistance of Cr can then be decreased.Therefore,the Cu layer as well as the outer layer of Cr usually deposited for decreasing the sheet resistance of Cr and for preventing Cu from oxidation,respectively, can be saved.The conversion effecioncy of Cr-MIS solar cell is of 12%,based on the active area of 1.3cm2 at AM1.5 (100mW/cm2).
1986, 3(2): 53-57
Abstract:
KTbP4O12 and aseries of KLa1-xTbxP4O12 crystals were grown from phosphoric acid by evaporation solution method. The experimental conditions of erystal growth were discussed. The crystal structures of KTbP4O12 were measured by x-ray and infrared spectra. It was found that there exist two types of structure, i. e. α and β structure. The fluorescent spectra of KTbP4O12 and KLa1-xTbxP4O12 were determined, the former emits strong green fluorescence and may be used as a new laser or luminescence material.
KTbP4O12 and aseries of KLa1-xTbxP4O12 crystals were grown from phosphoric acid by evaporation solution method. The experimental conditions of erystal growth were discussed. The crystal structures of KTbP4O12 were measured by x-ray and infrared spectra. It was found that there exist two types of structure, i. e. α and β structure. The fluorescent spectra of KTbP4O12 and KLa1-xTbxP4O12 were determined, the former emits strong green fluorescence and may be used as a new laser or luminescence material.
1986, 3(2): 58-63
Abstract:
The infrared spectra in the range of 4000-100cm-1 of rare earth complexes of tetrakis(o-chlorophenyl) porphin(OCITPP) and tetraphenylporphin(TPP)have been measured and assigned. The differences between the IR spectra of these ortho-chlorophenyl substituted and unsubstituted metalloporphins have been found and interpreted as well.
The infrared spectra in the range of 4000-100cm-1 of rare earth complexes of tetrakis(o-chlorophenyl) porphin(OCITPP) and tetraphenylporphin(TPP)have been measured and assigned. The differences between the IR spectra of these ortho-chlorophenyl substituted and unsubstituted metalloporphins have been found and interpreted as well.
1986, 3(2): 64-66
Abstract:
The catalytic activities of iron(Ⅲ) porphyrins with an axially ligated imidazole(Im),2-methylimidazole (MeIm), pyridine (Py), or 4-methylpyridine (MePy), for the selective oxidation of cyclohexane in the model system have been investigated. It has been found that with imidazole ligand, a strong donor, the catalytic activity of iron porphyrin is slightly higher than that of hemin. The catalytic activities of the complexes derease in the order of Hemin·Im≈Hemin·MeIm >Hemin·Py≈Hemin·MePy≈Hemin>ClFe (Ⅲ)TPP·Im >ClFe (Ⅲ) TPP.
The catalytic activities of iron(Ⅲ) porphyrins with an axially ligated imidazole(Im),2-methylimidazole (MeIm), pyridine (Py), or 4-methylpyridine (MePy), for the selective oxidation of cyclohexane in the model system have been investigated. It has been found that with imidazole ligand, a strong donor, the catalytic activity of iron porphyrin is slightly higher than that of hemin. The catalytic activities of the complexes derease in the order of Hemin·Im≈Hemin·MeIm >Hemin·Py≈Hemin·MePy≈Hemin>ClFe (Ⅲ)TPP·Im >ClFe (Ⅲ) TPP.
1986, 3(2): 67-69
Abstract:
The rate and mechanism of extraction of calcium by HDEHP in benzene from nitrate solution have been investigated using the Single Drop Method. The result indicates that the orders of reaction are 1,-1, and 1.5 with respect to[Ca2+],[H+] and [H2A2]o respectively, and the rate of the reaction depends upon the specific surface of thedroplets. The mechanism of the reaction was proposed.
The rate and mechanism of extraction of calcium by HDEHP in benzene from nitrate solution have been investigated using the Single Drop Method. The result indicates that the orders of reaction are 1,-1, and 1.5 with respect to[Ca2+],[H+] and [H2A2]o respectively, and the rate of the reaction depends upon the specific surface of thedroplets. The mechanism of the reaction was proposed.
1986, 3(2): 70-73
Abstract:
Analyzing the photochemical reaction products of 3,4-polyisoprene-2,6-bis (4'-azidobenzal) cyclohexanone system containing hydroquinone, it is confirmed that the active dinitrene can be quenched by hydroquinone. Experimental results imply the deficiencies in Эфрос's statrment that hydroquinone does not affect the photocrosslinking reaction of photopolymer composed of 3,4-polyisoprene and 2,6-bis(4'-azidobenzal) cyclohexanone.
Analyzing the photochemical reaction products of 3,4-polyisoprene-2,6-bis (4'-azidobenzal) cyclohexanone system containing hydroquinone, it is confirmed that the active dinitrene can be quenched by hydroquinone. Experimental results imply the deficiencies in Эфрос's statrment that hydroquinone does not affect the photocrosslinking reaction of photopolymer composed of 3,4-polyisoprene and 2,6-bis(4'-azidobenzal) cyclohexanone.
1986, 3(2): 74-76
Abstract:
Polyacrylamide (PAM) and its hydrolysed product (HPAM) were studied viscosimetrically in aqueous solution of 1, 0.5, 0, 1, 0.025 and 0.01N NaNO3. A linear relationship between tga (see Fig. 1) and degree of hydrolysis (DH%) was found with the same concentration of added salt (Cs) and the same molecular weight of polymers. It was also found that the intrinsic viscosity[η] of PAM and HPAM is proportional to the C3-1/2. The same[η]∞values of samples were obtained when the polymer has the same initial molecular weight, but different DH%.
Polyacrylamide (PAM) and its hydrolysed product (HPAM) were studied viscosimetrically in aqueous solution of 1, 0.5, 0, 1, 0.025 and 0.01N NaNO3. A linear relationship between tga (see Fig. 1) and degree of hydrolysis (DH%) was found with the same concentration of added salt (Cs) and the same molecular weight of polymers. It was also found that the intrinsic viscosity[η] of PAM and HPAM is proportional to the C3-1/2. The same[η]∞values of samples were obtained when the polymer has the same initial molecular weight, but different DH%.
1986, 3(2): 77-80
Abstract:
The effect of halogen atom in the (CF3COO)2NdX·EtOH-R3Al (X:Cl, Br,I;R:Et,i-Bu) catalyst system on the polymerization of butadiene or isoprene has been studied. The results indicate that the catalyst containing halogen atom with higher eletronegativity is more active. The intrinsic viscosities of polybutadiene and polyisoprene catalyzed with (CF3COO)2NdX·EtOH-Et3Al system were found in the order of Br >Cl >I while that obtained with (CF3 COO)2NdX·EtOH-i-Bu3Al system Cl >Br >I. The catalysts with different halogen lead to the microstructure change of the polymer obtained, but the active species of the catalyst system have little effect on the cis-contents of polymers.
The effect of halogen atom in the (CF3COO)2NdX·EtOH-R3Al (X:Cl, Br,I;R:Et,i-Bu) catalyst system on the polymerization of butadiene or isoprene has been studied. The results indicate that the catalyst containing halogen atom with higher eletronegativity is more active. The intrinsic viscosities of polybutadiene and polyisoprene catalyzed with (CF3COO)2NdX·EtOH-Et3Al system were found in the order of Br >Cl >I while that obtained with (CF3 COO)2NdX·EtOH-i-Bu3Al system Cl >Br >I. The catalysts with different halogen lead to the microstructure change of the polymer obtained, but the active species of the catalyst system have little effect on the cis-contents of polymers.
