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1989 Volume 7 Issue 3
1989, 7(3): 193-201
Abstract:
1989, 7(3): 202-206
Abstract:
A study has been made on the plasma polymerization of acetylene/CO2/H2 in a capacitively coupled RF plasma. The monomer mixture yielded a crosslinked film with light brown color. A kinetic study is reported for the plasma polymer ization of acetylene/CO2/H2. The effects of discharge power level and reactor geometry on the rate of polymer formation are reported. The structure of the plasma polymer is investigated by IR study.
A study has been made on the plasma polymerization of acetylene/CO2/H2 in a capacitively coupled RF plasma. The monomer mixture yielded a crosslinked film with light brown color. A kinetic study is reported for the plasma polymer ization of acetylene/CO2/H2. The effects of discharge power level and reactor geometry on the rate of polymer formation are reported. The structure of the plasma polymer is investigated by IR study.
1989, 7(3): 207-211
Abstract:
Polymer electrolytes based on poly (methylsiloxane-g-ethylene oxide) and LiClO4 have been prepared. The network films crosslinked by a crosslinking agent are found to exhibit a considerably high ionic conductivity of about 10-4 Scm-1 at room temperature and have good flexibility.
Polymer electrolytes based on poly (methylsiloxane-g-ethylene oxide) and LiClO4 have been prepared. The network films crosslinked by a crosslinking agent are found to exhibit a considerably high ionic conductivity of about 10-4 Scm-1 at room temperature and have good flexibility.
1989, 7(3): 212-218
Abstract:
The morphology of a thermotropic aromatic polyester during the transitions between isotropic and anisotropic melts was studied by means of polarizing microscopy and small angle light scattering techniques. Both transition processes were found to be composed of the initiation of a new phase at local places of the old phase matrix and the growth of the new phase domains. A change of Hv scattering patterns was observed in the transition temperature ranges and was explained as the result of heterogeneity of the mesophase system,but not the change in ordering of a homogeneous mesophase.
The morphology of a thermotropic aromatic polyester during the transitions between isotropic and anisotropic melts was studied by means of polarizing microscopy and small angle light scattering techniques. Both transition processes were found to be composed of the initiation of a new phase at local places of the old phase matrix and the growth of the new phase domains. A change of Hv scattering patterns was observed in the transition temperature ranges and was explained as the result of heterogeneity of the mesophase system,but not the change in ordering of a homogeneous mesophase.
1989, 7(3): 219-224
Abstract:
A series of porous microspheres of linear and ethylene diacrylate (M') cross-linked copolymers of 2-vinylpyridine (V) and methyl acrylate (M) reacted with tetracarbonyldichlorodirhodium to form a series of cis-dicarbonylrhodium chelate complex (MVRh and MVM 'Rh). They are thermally stable yet very reactive in the carbonylation of methanol to acetic acid, and of methanol-acetic acid mixture to acetic acid and acetic anhydride with a selectivity of 100% under relatively mild and anhydrous conditions.
A series of porous microspheres of linear and ethylene diacrylate (M') cross-linked copolymers of 2-vinylpyridine (V) and methyl acrylate (M) reacted with tetracarbonyldichlorodirhodium to form a series of cis-dicarbonylrhodium chelate complex (MVRh and MVM 'Rh). They are thermally stable yet very reactive in the carbonylation of methanol to acetic acid, and of methanol-acetic acid mixture to acetic acid and acetic anhydride with a selectivity of 100% under relatively mild and anhydrous conditions.
1989, 7(3): 225-231
Abstract:
The kinetic study of carbonylation of methanol-acetic acid mixture to acetic acid and acetic anhydride over a cis-dicarbonylrhodium complex (MVM' Rh) coordinated with the ethylene diacrylate (M') crosslinked copolymer of methyl acrylate (M) and 2-vinylpyddine (V)shows that the rate of reaction is zero order with respect to both reactants methanol and carbon monoxide, but first order in the concentrations of promoter methyl iodide and rhodium in the complex. Polar solvents can accelerate the reaction. Activation parameters were calculated from the experimental results,being comparable to that of the homogeneous system.A mechanism similar to that of soluble rhodium catalyst was proposed.
The kinetic study of carbonylation of methanol-acetic acid mixture to acetic acid and acetic anhydride over a cis-dicarbonylrhodium complex (MVM' Rh) coordinated with the ethylene diacrylate (M') crosslinked copolymer of methyl acrylate (M) and 2-vinylpyddine (V)shows that the rate of reaction is zero order with respect to both reactants methanol and carbon monoxide, but first order in the concentrations of promoter methyl iodide and rhodium in the complex. Polar solvents can accelerate the reaction. Activation parameters were calculated from the experimental results,being comparable to that of the homogeneous system.A mechanism similar to that of soluble rhodium catalyst was proposed.
1989, 7(3): 232-238
Abstract:
This paper describes the synthesis and free radical ring-opening polymerization of 2-methyl-and 2-methyl-9-n-butyl (-7-methylene-1, 4, 6-trioxaspiro (4, 4) nonane). The structures of the two polymers were verified by IR, 'H and 13C NMR spectra. The substituent on 9-position of 7-methylene-trioxaspiro (4, 4) nonane affects the structure of polymer and polymerization activity. The polymerization mechanism is discussed.
This paper describes the synthesis and free radical ring-opening polymerization of 2-methyl-and 2-methyl-9-n-butyl (-7-methylene-1, 4, 6-trioxaspiro (4, 4) nonane). The structures of the two polymers were verified by IR, 'H and 13C NMR spectra. The substituent on 9-position of 7-methylene-trioxaspiro (4, 4) nonane affects the structure of polymer and polymerization activity. The polymerization mechanism is discussed.
1989, 7(3): 239-244
Abstract:
The coordination polymerization of benzotriazole with metallic copper has been investigated by infrared and X-ray photoelectron spectroscopies. We found that benzotriazole could react with copper (0) under mild conditions to form bis (benzotriazolato) copper (Ⅱ) and benzotriazolato copper (Ⅰ)which covered the surface of copper metal in the shape of polymeric materials. Since benzotriazole is of great interest as a ligand in that its presence in many biological system with metal ions, and is considered as a corrosion inhibitor,this work will be in favour of the study of protective corrosion.
The coordination polymerization of benzotriazole with metallic copper has been investigated by infrared and X-ray photoelectron spectroscopies. We found that benzotriazole could react with copper (0) under mild conditions to form bis (benzotriazolato) copper (Ⅱ) and benzotriazolato copper (Ⅰ)which covered the surface of copper metal in the shape of polymeric materials. Since benzotriazole is of great interest as a ligand in that its presence in many biological system with metal ions, and is considered as a corrosion inhibitor,this work will be in favour of the study of protective corrosion.
1989, 7(3): 245-251
Abstract:
The present paper deals with the kinetics of polymerization of acrylonitrile (AN) initialed by the redox system of polypropylene-based vanadyi polyimidodiacetate (PV)-thiourea (TU)in aqueous sulfuric acid in the temperature range from 25 to 40℃. The polymerization rate was measured by varying the concentrations of monomer, vanadyl polyimidodiacetate, thiourea and sulfuric acid. The overall rate of polymerization was summarized as Rp=2.2×105e-6.560/RT [AN]1.0[PV]0.50[TU]1.5[H2SO4]2.0 The molecular weight of polyacrylonitrile based on the experimental data was:Mn=k·1/T·[AN]/[PV]0.50[TU]1.5[H2SO4]2.0 These results indicated that the chain radicals are terminated by combination and/or disproportionation rather than chain transfer.The cooperation effect of carboxylic groups and the macromolecular field effect of polymer supporter are the characters of vanadyl polyimidiacetate such as the case reported in early paper[1].
The present paper deals with the kinetics of polymerization of acrylonitrile (AN) initialed by the redox system of polypropylene-based vanadyi polyimidodiacetate (PV)-thiourea (TU)in aqueous sulfuric acid in the temperature range from 25 to 40℃. The polymerization rate was measured by varying the concentrations of monomer, vanadyl polyimidodiacetate, thiourea and sulfuric acid. The overall rate of polymerization was summarized as Rp=2.2×105e-6.560/RT [AN]1.0[PV]0.50[TU]1.5[H2SO4]2.0 The molecular weight of polyacrylonitrile based on the experimental data was:Mn=k·1/T·[AN]/[PV]0.50[TU]1.5[H2SO4]2.0 These results indicated that the chain radicals are terminated by combination and/or disproportionation rather than chain transfer.The cooperation effect of carboxylic groups and the macromolecular field effect of polymer supporter are the characters of vanadyl polyimidiacetate such as the case reported in early paper[1].
1989, 7(3): 252-257
Abstract:
The polysaccharide having weight-average molecular weight M_w=1. 09×10~5, isolated from the sap of lac trees (Vietnam), was separated into 12 fractions by aqueous-phase preparative gel permeation chromatography. The molecular weights and molecular weight distributions of the fractions were measured in aqueous 0.08M KCl/0.01 M NaAc and 0.4M KCl/0.05M NaAc at pH =7. 6 by light scattering, viscometry and gel permeation chromatography. The Mark-Houwink equation in aqueous 0.08M KCl/0.01M NaAc at 30℃ was found to be [η]=2.28×10-2M0.52w(cm3/g),which indicated the polysaccharide chain in the aqueous solution to be a spherical random coil.
The polysaccharide having weight-average molecular weight M_w=1. 09×10~5, isolated from the sap of lac trees (Vietnam), was separated into 12 fractions by aqueous-phase preparative gel permeation chromatography. The molecular weights and molecular weight distributions of the fractions were measured in aqueous 0.08M KCl/0.01 M NaAc and 0.4M KCl/0.05M NaAc at pH =7. 6 by light scattering, viscometry and gel permeation chromatography. The Mark-Houwink equation in aqueous 0.08M KCl/0.01M NaAc at 30℃ was found to be [η]=2.28×10-2M0.52w(cm3/g),which indicated the polysaccharide chain in the aqueous solution to be a spherical random coil.
1989, 7(3): 258-265
Abstract:
Functional monomer (MP)2PT having tertiary aromatic amino group was systhesized from the reaction of N, N-di (2-hydroxypropyl)-p-toluidine with 2-methyl acryloyl chloride. In the presence of organic peroxide, the radical polymerization of (MP)2PT in toluene took place. The kinetics of (MP)2PT polymerization and the ESR spectra of LPO-(MP)2PT-MNP systems were determined respectively.
Functional monomer (MP)2PT having tertiary aromatic amino group was systhesized from the reaction of N, N-di (2-hydroxypropyl)-p-toluidine with 2-methyl acryloyl chloride. In the presence of organic peroxide, the radical polymerization of (MP)2PT in toluene took place. The kinetics of (MP)2PT polymerization and the ESR spectra of LPO-(MP)2PT-MNP systems were determined respectively.
1989, 7(3): 266-269
Abstract:
Aromatic polybenzothiazolamides were prepared by low temperature solution method by condensing the 2, 2'-diarnino-6, 6'-bibenzothiazole with four different acid chlorides in quantitative yield. These polymers were characterized by IR and NMR. Viscosities of these polyamides range from 0.42 to 1 dl/gm. All these polymers were stable upto 300℃ in air.
Aromatic polybenzothiazolamides were prepared by low temperature solution method by condensing the 2, 2'-diarnino-6, 6'-bibenzothiazole with four different acid chlorides in quantitative yield. These polymers were characterized by IR and NMR. Viscosities of these polyamides range from 0.42 to 1 dl/gm. All these polymers were stable upto 300℃ in air.
1989, 7(3): 270-279
Abstract:
Ultrasonic absorption and velocity measurements were made on aqueous solutions of poly (ethylene glycol)(PEG)of different molecular weights and concentrations, using a pulse sender-receiver ultrasonic generator, Measurements were obtained at a frequency of 2MHz. , and a temperature of 293 K. The results show a linear increase of the Values of velocity, density and viscosity with increase of molecu lar weight and concentration of PEG. On the contrary, the attenuation values decreased with increase of molecular weight and concentration of PEG.A mathematical equation correlating relaxation amplitude and molecular weight of the polymer is suggested.This was applied to calculate the molecular weights of unknown samples of PEG from their measured relaxation amplitude.The results obtained were in good agreement with those obtained from osmometry.
Ultrasonic absorption and velocity measurements were made on aqueous solutions of poly (ethylene glycol)(PEG)of different molecular weights and concentrations, using a pulse sender-receiver ultrasonic generator, Measurements were obtained at a frequency of 2MHz. , and a temperature of 293 K. The results show a linear increase of the Values of velocity, density and viscosity with increase of molecu lar weight and concentration of PEG. On the contrary, the attenuation values decreased with increase of molecular weight and concentration of PEG.A mathematical equation correlating relaxation amplitude and molecular weight of the polymer is suggested.This was applied to calculate the molecular weights of unknown samples of PEG from their measured relaxation amplitude.The results obtained were in good agreement with those obtained from osmometry.
1989, 7(3): 280-287
Abstract:
Infrared spectra at different temperatures have been studied for fractions ofa liquid crystal tormmg aromatic polyester. The molecular interactions in different phases and their changes duringthe transitions were discussed. Abrupt frequency shift was found for bands of groups both in mesogens and flexible spacers during fusion and isotropization transitions. It may imply that both the mesogens and the flexible spacers are included in the same crystalline phase and give their contributions to the formation of the mesophase.The splitting into doublet of the C—O stretching vibrations was observed for both the aromatic and aliphatic esters and was attributed to the existence of local regions for ester groups different in ordering.The more ordered regions do not disappear comletely even in the isotropic liquid phase.
Infrared spectra at different temperatures have been studied for fractions ofa liquid crystal tormmg aromatic polyester. The molecular interactions in different phases and their changes duringthe transitions were discussed. Abrupt frequency shift was found for bands of groups both in mesogens and flexible spacers during fusion and isotropization transitions. It may imply that both the mesogens and the flexible spacers are included in the same crystalline phase and give their contributions to the formation of the mesophase.The splitting into doublet of the C—O stretching vibrations was observed for both the aromatic and aliphatic esters and was attributed to the existence of local regions for ester groups different in ordering.The more ordered regions do not disappear comletely even in the isotropic liquid phase.
