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1996 Volume 14 Issue 3
1996, 14(3): 193-198
Abstract:
In this work, controlling of the particle size of PVC in PS/PVC blends was studied. Itis shown that viscosity ratio and particle size can be changed by adding a third composition,such as plasticizers, and the distribution of the third composition in two phases plays avery important role in controlling viscosity ratio and particle size. When DOP was used asthe plasticizer of PVC in PS/PVC blends, the particle size of PVC could not be reduceddue to the transference of DOP into PS phase. When polycaprolactone (PCL) was used as the plasticizer of PVC in the same blends,the particle size of PVC could be descreased obviously because PCL does not migrate to PS phase.
In this work, controlling of the particle size of PVC in PS/PVC blends was studied. Itis shown that viscosity ratio and particle size can be changed by adding a third composition,such as plasticizers, and the distribution of the third composition in two phases plays avery important role in controlling viscosity ratio and particle size. When DOP was used asthe plasticizer of PVC in PS/PVC blends, the particle size of PVC could not be reduceddue to the transference of DOP into PS phase. When polycaprolactone (PCL) was used as the plasticizer of PVC in the same blends,the particle size of PVC could be descreased obviously because PCL does not migrate to PS phase.
1996, 14(3): 199-204
Abstract:
A silica-supported carboxymethylcellulose platinum complex (abbreviated as SiO2-CMC-Pt) has been prepared and characterized by XPS. Its catalytic properties for hydro-genation of aromatic compounds were studied. The results showed that this catalystcould catalyze the hydrogenation of phenol, anisol, p-cresol, benzene and toluene to cyclo-hexanol, cyclohexyl methyl ether, p-methyl cyclohexanol, cyclohexane and methylcyclo-hexane, respectively in 100% yield at 30℃ and 1 atm. In the hydrogenation of phenol,COO/Pt ratio in SiO2-CMC-Pt has much influence on the initial hydrogenation rate and the selectivity for the intermediate product,cyclohexanone.The highest initial rate and the highest yield of cyclohexanone both occur at COO/Pt ratio of 6.The complex is stable during the reaction and can be used repeatedly.
A silica-supported carboxymethylcellulose platinum complex (abbreviated as SiO2-CMC-Pt) has been prepared and characterized by XPS. Its catalytic properties for hydro-genation of aromatic compounds were studied. The results showed that this catalystcould catalyze the hydrogenation of phenol, anisol, p-cresol, benzene and toluene to cyclo-hexanol, cyclohexyl methyl ether, p-methyl cyclohexanol, cyclohexane and methylcyclo-hexane, respectively in 100% yield at 30℃ and 1 atm. In the hydrogenation of phenol,COO/Pt ratio in SiO2-CMC-Pt has much influence on the initial hydrogenation rate and the selectivity for the intermediate product,cyclohexanone.The highest initial rate and the highest yield of cyclohexanone both occur at COO/Pt ratio of 6.The complex is stable during the reaction and can be used repeatedly.
1996, 14(3): 205-210
Abstract:
This study is concerned with the removal of Staph aureus from water by polyurethaneionomers. All the samples are quaternary ammonium salts which possess a positive chargeon the surface. The ratio of the soft segment to diisocyanate and chain extender is 1:2:1and the ionization degree is 100%. The ionomers strongly capture microbial cells on theirsurfaces in a living state and the hydrophilicity of polymer matrix used in the studyenhanced the affinity of the polymer for bacterial cells. The adhesion of the microorganism to polymer was due mainly to electrostatic interaction between them.The calculation of the viable all count showed that D value for Staph·aureus is not proportional to the nitrogen concentration.The microorganism capture ability of pyridinium-containing polymer is greater than that of piperazine based samples.
This study is concerned with the removal of Staph aureus from water by polyurethaneionomers. All the samples are quaternary ammonium salts which possess a positive chargeon the surface. The ratio of the soft segment to diisocyanate and chain extender is 1:2:1and the ionization degree is 100%. The ionomers strongly capture microbial cells on theirsurfaces in a living state and the hydrophilicity of polymer matrix used in the studyenhanced the affinity of the polymer for bacterial cells. The adhesion of the microorganism to polymer was due mainly to electrostatic interaction between them.The calculation of the viable all count showed that D value for Staph·aureus is not proportional to the nitrogen concentration.The microorganism capture ability of pyridinium-containing polymer is greater than that of piperazine based samples.
1996, 14(3): 211-216
Abstract:
Polyazoamide(PAA) was used as initiator to prepare block copolymer P(MMA-b-St) byfree radical polymerization. The fraction of block copolymer was about 50%. The structureof the block-copolymer was characterized by IR and the results of 1H-NMR and GPCshowed that the content of the block and the molecular weight (Mw) of the prepolymerand block copolymer could be controlled by varying the mol ratio of styrene/PAA andMMA/prepolymer. DSC and TEM results revealed that the block copolymer has two separated glass transition temperatures and phase separation within the domain structure.
Polyazoamide(PAA) was used as initiator to prepare block copolymer P(MMA-b-St) byfree radical polymerization. The fraction of block copolymer was about 50%. The structureof the block-copolymer was characterized by IR and the results of 1H-NMR and GPCshowed that the content of the block and the molecular weight (Mw) of the prepolymerand block copolymer could be controlled by varying the mol ratio of styrene/PAA andMMA/prepolymer. DSC and TEM results revealed that the block copolymer has two separated glass transition temperatures and phase separation within the domain structure.
1996, 14(3): 217-224
Abstract:
D-72 resin supported nickel-copper catalysts prepared by solvated metal atom impreg-nation (SMAI) were studied by magnetic measurements and X-ray photoelectron spectro-scopy (XPS). The Ni particles on the catalysts are very highly dispersed and displaysuperparamagnetic behaviour. Ni-Cu alloy clusters were found to be formed. The sur-face compositions are different from the bulk concentrations. In contrast with the surfaceenrichment in copper generally observed on conventional Ni-Cu catalysts, the surfaces of these catalysts are enriched in nickel.The nickel is in both zero and valent states,while copper is mainly in metallic state.Catalytic data show that the formation of Ni-Cu alloy clusters has a profound effect on the catalytic activities of the catalysts in the hydrogenation of furfural.The activity of the Ni:Cu ratio of one bimetallic catalysts is much higher than that of the Ni or Cu monometallic catalyst.
D-72 resin supported nickel-copper catalysts prepared by solvated metal atom impreg-nation (SMAI) were studied by magnetic measurements and X-ray photoelectron spectro-scopy (XPS). The Ni particles on the catalysts are very highly dispersed and displaysuperparamagnetic behaviour. Ni-Cu alloy clusters were found to be formed. The sur-face compositions are different from the bulk concentrations. In contrast with the surfaceenrichment in copper generally observed on conventional Ni-Cu catalysts, the surfaces of these catalysts are enriched in nickel.The nickel is in both zero and valent states,while copper is mainly in metallic state.Catalytic data show that the formation of Ni-Cu alloy clusters has a profound effect on the catalytic activities of the catalysts in the hydrogenation of furfural.The activity of the Ni:Cu ratio of one bimetallic catalysts is much higher than that of the Ni or Cu monometallic catalyst.
1996, 14(3): 225-232
Abstract:
Blends of polyphenylene sulfide (PPS) containing trace amounts of branching and/orcross-linking in chain and Polyamide-66(PA-66) have been prepared by melt blending. Therheological behavior of PPS/PA-66 blends has been studied by means of capillary rheo-meter, and compared with PPS. The effects of shear rate, shear stress and temperature onthe flow of PPS/PA-66 blends and PPS are discussed. The non-Newtonian indexes andthe activation energies of viscous flow are obtained. The results show that the apparent viscosity of PPS/PA-66 blends is not sensitive to shear rate and stress,but decreases with the elevation of temperature.On the contrary,the apparent viscosity of the PPS decreases obviously with the increasing of shear rete and shear stress,but it is increased by the elevation of temperatue.
Blends of polyphenylene sulfide (PPS) containing trace amounts of branching and/orcross-linking in chain and Polyamide-66(PA-66) have been prepared by melt blending. Therheological behavior of PPS/PA-66 blends has been studied by means of capillary rheo-meter, and compared with PPS. The effects of shear rate, shear stress and temperature onthe flow of PPS/PA-66 blends and PPS are discussed. The non-Newtonian indexes andthe activation energies of viscous flow are obtained. The results show that the apparent viscosity of PPS/PA-66 blends is not sensitive to shear rate and stress,but decreases with the elevation of temperature.On the contrary,the apparent viscosity of the PPS decreases obviously with the increasing of shear rete and shear stress,but it is increased by the elevation of temperatue.
1996, 14(3): 233-239
Abstract:
Copolymer of 2-vinylpyridine and vinylacetate coordinated with dicarbonylrhodiumused as a catalyst for carbonylation of methanol to acetic acid and anhydride has beenstudied. The structural characteristics of the copolymer ligand and complex, and the in-fluences of the reaction conditions on the carbonylation catalyzed by this polymer complexhave been investigated. In comparison with small molecule catalyst of Rh complex, thebidentate copolymer coordinated complex has better thermal stability. The reaction mechanism of the carbonylation reaction is also illustrated.
Copolymer of 2-vinylpyridine and vinylacetate coordinated with dicarbonylrhodiumused as a catalyst for carbonylation of methanol to acetic acid and anhydride has beenstudied. The structural characteristics of the copolymer ligand and complex, and the in-fluences of the reaction conditions on the carbonylation catalyzed by this polymer complexhave been investigated. In comparison with small molecule catalyst of Rh complex, thebidentate copolymer coordinated complex has better thermal stability. The reaction mechanism of the carbonylation reaction is also illustrated.
1996, 14(3): 240-247
Abstract:
A comb polymer with oligo-oxyethylene side chains of the type -(CH2CH2O)12CH3was prepared from methyl vinyl ether/maleic anhydride copolymer and poly (ethyleneglycol) methyl ether. The polymer can dissolve LiClO4 salt to form homogeneous amor-phous polymer electrolyte. The ac ion conduction was measured using the complex impedancemethod, and conductivities were investigated as functions of temperatures and salt con-centration. The complexes were first found to have two classes of glass transition which increase with increasing,salt content.The optimum conductivity attained ta 25℃ is in the order of 5.50×10-6Scm-1.IR spectroscopy was used to study the cation-polymer interaction.
A comb polymer with oligo-oxyethylene side chains of the type -(CH2CH2O)12CH3was prepared from methyl vinyl ether/maleic anhydride copolymer and poly (ethyleneglycol) methyl ether. The polymer can dissolve LiClO4 salt to form homogeneous amor-phous polymer electrolyte. The ac ion conduction was measured using the complex impedancemethod, and conductivities were investigated as functions of temperatures and salt con-centration. The complexes were first found to have two classes of glass transition which increase with increasing,salt content.The optimum conductivity attained ta 25℃ is in the order of 5.50×10-6Scm-1.IR spectroscopy was used to study the cation-polymer interaction.
1996, 14(3): 248-254
Abstract:
A series of acrylic ester copolymers with viologen group as pendant were synthesizedthrough the reaction of MMA-EBA (Ethenyl bromoacetate) copolymer with 4-(4'-pyridyl)-N-alkyl (or arylalkyl) pyridiniums. These viologen copolymers can exchange their anionwith NH4PF6 in methanol to improve their solubility in organic solvents such as DMFand acetone. Compared with the corresponding low molecular viologens, these viologencopolymers have relatively lower color development rate under UV light and fade faster in air due to less affinity to photo-reductant and deficiency of association between their cation radicals.Their photofatigue resistant ability is also slightly better than that of low molecular viologens.
A series of acrylic ester copolymers with viologen group as pendant were synthesizedthrough the reaction of MMA-EBA (Ethenyl bromoacetate) copolymer with 4-(4'-pyridyl)-N-alkyl (or arylalkyl) pyridiniums. These viologen copolymers can exchange their anionwith NH4PF6 in methanol to improve their solubility in organic solvents such as DMFand acetone. Compared with the corresponding low molecular viologens, these viologencopolymers have relatively lower color development rate under UV light and fade faster in air due to less affinity to photo-reductant and deficiency of association between their cation radicals.Their photofatigue resistant ability is also slightly better than that of low molecular viologens.
1996, 14(3): 255-260
Abstract:
The polymerization kinetics of 4, 4'-biphenyldicarbonitrile and other substituted ben-zonitriles catalyzed by cobaltic acetylacetonate was studied. The structure of polymer ofdifferent substituted benzonitrile was also determined. It is found that the rate of polymeri-zation and the structure of polymer is greatly affected by the substituent of benzonitriles.
The polymerization kinetics of 4, 4'-biphenyldicarbonitrile and other substituted ben-zonitriles catalyzed by cobaltic acetylacetonate was studied. The structure of polymer ofdifferent substituted benzonitrile was also determined. It is found that the rate of polymeri-zation and the structure of polymer is greatly affected by the substituent of benzonitriles.
1996, 14(3): 261-269
Abstract:
A series of polyacrylate emulsions were blended with tackifier resin emulsions such asmodified rosin emulsion, C5 resin and C9 resin emulsion. The miscibility of the polyacry-lates and tackifier resins was investigated by means of SEM and visual observation. Thephase diagrams of the miscibility change systematically with the polarity of polyacrylatesand tackifier resins. The influence of the content of the tackifier resins on the adhesionproperties of the polyacrylate emulsions were also studied. The results show that the 180℃ peel strength is improved as the amount of the tackifier resin increases and comes to a maximum at a specific content.The ball tack property decreases slightly and the hold strength changes complicatedly as the tackifier resin increases.
A series of polyacrylate emulsions were blended with tackifier resin emulsions such asmodified rosin emulsion, C5 resin and C9 resin emulsion. The miscibility of the polyacry-lates and tackifier resins was investigated by means of SEM and visual observation. Thephase diagrams of the miscibility change systematically with the polarity of polyacrylatesand tackifier resins. The influence of the content of the tackifier resins on the adhesionproperties of the polyacrylate emulsions were also studied. The results show that the 180℃ peel strength is improved as the amount of the tackifier resin increases and comes to a maximum at a specific content.The ball tack property decreases slightly and the hold strength changes complicatedly as the tackifier resin increases.
1996, 14(3): 270-276
Abstract:
Electropolymerization of pyrrole under ultrasonic field at 20kHz was performed ina series of aqueous and propylene carbonate (PC) solutions. The ultrasonic wave withmoderate intensity at the power of 44W, which is the power threshold of the ultrasonicgenerator used in this work to produce cavitation effect, enhance the conductivity andtensile strength of the polypyrrole films as prepared. However, too high intensity of theultrasonic wave is harmful to the polymerization.
Electropolymerization of pyrrole under ultrasonic field at 20kHz was performed ina series of aqueous and propylene carbonate (PC) solutions. The ultrasonic wave withmoderate intensity at the power of 44W, which is the power threshold of the ultrasonicgenerator used in this work to produce cavitation effect, enhance the conductivity andtensile strength of the polypyrrole films as prepared. However, too high intensity of theultrasonic wave is harmful to the polymerization.
1996, 14(3): 277-283
Abstract:
A series of Si-containing polyester-polyether multiblock copolymers were synthesizedby transesterification and melt copolycondensation of organosilicon monomers [1, 1, 3, 3-tetramethyl-1, 3-bis (p-carbomethoxyphenyl) disiloxane] (I ) or dimethyl bis (p-carbometh-oxyphenyl) silane] (II) and dimethyl terephthalate (DMT), with 1, 4-butanediol, poly-tetramethylene glycol (PTMG) respectively. The organosilicon monomers were preparedby Grinard reaction, oxidation and esterification. The structures of the above monomers (I),(II) and the copolymers were characterized by MS anal.and 1H-NMR.
A series of Si-containing polyester-polyether multiblock copolymers were synthesizedby transesterification and melt copolycondensation of organosilicon monomers [1, 1, 3, 3-tetramethyl-1, 3-bis (p-carbomethoxyphenyl) disiloxane] (I ) or dimethyl bis (p-carbometh-oxyphenyl) silane] (II) and dimethyl terephthalate (DMT), with 1, 4-butanediol, poly-tetramethylene glycol (PTMG) respectively. The organosilicon monomers were preparedby Grinard reaction, oxidation and esterification. The structures of the above monomers (I),(II) and the copolymers were characterized by MS anal.and 1H-NMR.
1996, 14(3): 284-288
Abstract:
The methanolysis of poly(triphenylmethyl methacrylate) (PTrMA) and its copoly-mers P(TrMA-co-MMA), P(TrMA-b-MMA) has been studied in the presence of anhydrousmethanol at 40℃ by electroconductometric method. It has been found that the methanoly-sis stability can be obviously improved for the copolymer, especially, the radom copolymer,P(TrMA-co-MMA).
The methanolysis of poly(triphenylmethyl methacrylate) (PTrMA) and its copoly-mers P(TrMA-co-MMA), P(TrMA-b-MMA) has been studied in the presence of anhydrousmethanol at 40℃ by electroconductometric method. It has been found that the methanoly-sis stability can be obviously improved for the copolymer, especially, the radom copolymer,P(TrMA-co-MMA).
