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2002 Volume 19 Issue 9
2002, 19(9): 817-821
Abstract:
Macroporous crosslingked poly(2-hydroxyethyl methacrylate)(PHEMA) beads were prepared via a suspension polymerization technique by reacting 2-hydroxyethyl methacrylate(HEMA) with ethyleneglycol dimethylacrylate(EGDMA) as crosslinking agent as well as ethyl acetate or mixture of ethyl acetate and dodecanol as porogenic agent. The effects of amount of crosslinking agent, kind, amount and composition of porogenic agent on the pore distribution, specific surface area and pore volume of PHEMA beads were investigated. It was found that the pore distribution of resin with ethyl acetate as porogenic agent was broader than that with mixed agents. The pore volume was found increased with increase in total amount of mixed porogenic agent and the amount of dodecanol, while specific surface area decreased. PHEMA resins have good swelling ability in common solvents with solubility parameters from 14.5 to 10.0.
Macroporous crosslingked poly(2-hydroxyethyl methacrylate)(PHEMA) beads were prepared via a suspension polymerization technique by reacting 2-hydroxyethyl methacrylate(HEMA) with ethyleneglycol dimethylacrylate(EGDMA) as crosslinking agent as well as ethyl acetate or mixture of ethyl acetate and dodecanol as porogenic agent. The effects of amount of crosslinking agent, kind, amount and composition of porogenic agent on the pore distribution, specific surface area and pore volume of PHEMA beads were investigated. It was found that the pore distribution of resin with ethyl acetate as porogenic agent was broader than that with mixed agents. The pore volume was found increased with increase in total amount of mixed porogenic agent and the amount of dodecanol, while specific surface area decreased. PHEMA resins have good swelling ability in common solvents with solubility parameters from 14.5 to 10.0.
2002, 19(9): 822-826
Abstract:
Blends (LLDPE/PS) of linear low density polyethylene(LLDPE) with polystyrene(PS) were prepared by a reactive extrusion method. In order to increase the compatibility of two blending components, a kind of Lewis acid catalyst, AlCl3, was adopted to initiate the Friedel-Crafts alkylation reaction between blending components. Due to the fact that in-situ generated LLDPE-g-PS copolymer could act as a compatibilizer in the relative blending system, the mechanical properties of LLDPE/PS system were greatly improved. For example, after compatibilization the Izod impact strength of a LLDPE/PS blend(80/20, by mass) was increased from 88.5 J/m to 401.6 J/m and its elongation-at-break increased from 370% to 790%. The Raman spectra of the LLDPE/PS blends extracted with tetrahydrofuran verified that LLDPE segments were grafted to the para-position of benzene rings of PS, which suggested that Friedel-Crafts alkylation did happen during reactive extrusion blending. SEM micrographs showed that the size of domains was decreased from 4~5 μm to less than 1 μm depending upon the mas fraction of AlCl3 added. The crystallization behavior of LLDPE/PS blend was investigated by DSC. The fractionated crystallization phenomena were noticed, which could be mainly attributed to the confined crystallization rather than the reduction of the size of LLDPE domains.
Blends (LLDPE/PS) of linear low density polyethylene(LLDPE) with polystyrene(PS) were prepared by a reactive extrusion method. In order to increase the compatibility of two blending components, a kind of Lewis acid catalyst, AlCl3, was adopted to initiate the Friedel-Crafts alkylation reaction between blending components. Due to the fact that in-situ generated LLDPE-g-PS copolymer could act as a compatibilizer in the relative blending system, the mechanical properties of LLDPE/PS system were greatly improved. For example, after compatibilization the Izod impact strength of a LLDPE/PS blend(80/20, by mass) was increased from 88.5 J/m to 401.6 J/m and its elongation-at-break increased from 370% to 790%. The Raman spectra of the LLDPE/PS blends extracted with tetrahydrofuran verified that LLDPE segments were grafted to the para-position of benzene rings of PS, which suggested that Friedel-Crafts alkylation did happen during reactive extrusion blending. SEM micrographs showed that the size of domains was decreased from 4~5 μm to less than 1 μm depending upon the mas fraction of AlCl3 added. The crystallization behavior of LLDPE/PS blend was investigated by DSC. The fractionated crystallization phenomena were noticed, which could be mainly attributed to the confined crystallization rather than the reduction of the size of LLDPE domains.
2002, 19(9): 827-831
Abstract:
Six series of aryloxy pyridazines derivatives have been synthesized starting from 3,6-dichloro-pyradizine. All of the resulting compounds are confirmed by 1H NMR and elemental analysis and some of them are characterized by IR and MS. Preliminary bioassay indicates that some of the compounds have certain herbicidal activity.
Six series of aryloxy pyridazines derivatives have been synthesized starting from 3,6-dichloro-pyradizine. All of the resulting compounds are confirmed by 1H NMR and elemental analysis and some of them are characterized by IR and MS. Preliminary bioassay indicates that some of the compounds have certain herbicidal activity.
2002, 19(9): 832-836
Abstract:
The preparation of diphenyl oxalate(DPO) by transesterification of dimethyl oxalate(DMO) with phenol over TS-1 catalyst(2.5% Ti) has been investigated as function of calcination temperature of the catalyst and reaction time. The catalysts were characterized by FTIR of absorbed pyridine and NH3-TPD. The results showed that weak Lewis acid sites were the active sites of the catalyst in the transesterification reaction. The optimum calcination temperature appeared to be 550℃ when its effect on the active sites and surface area of the catalysts were taken into consideration. At atmosphere pressure, reaction temperature 180℃, 4 h, n(PhOH): n(DMO)=5:1, 1.8 g catalyst, the following results were obtained:total selectivity of methylphenyl oxalate(MPO) and DPO was 99.3%, DMO conversion 30.0%, MPO yield 26.3% and DPO yield 3.4%.
The preparation of diphenyl oxalate(DPO) by transesterification of dimethyl oxalate(DMO) with phenol over TS-1 catalyst(2.5% Ti) has been investigated as function of calcination temperature of the catalyst and reaction time. The catalysts were characterized by FTIR of absorbed pyridine and NH3-TPD. The results showed that weak Lewis acid sites were the active sites of the catalyst in the transesterification reaction. The optimum calcination temperature appeared to be 550℃ when its effect on the active sites and surface area of the catalysts were taken into consideration. At atmosphere pressure, reaction temperature 180℃, 4 h, n(PhOH): n(DMO)=5:1, 1.8 g catalyst, the following results were obtained:total selectivity of methylphenyl oxalate(MPO) and DPO was 99.3%, DMO conversion 30.0%, MPO yield 26.3% and DPO yield 3.4%.
2002, 19(9): 837-841
Abstract:
According to the theory of wide angle X-ray diffractometry, the graphic multi-peak resolution results of WAXD patterns of the various crystal forms of syndiotactic polystyrene(sPS)(T', T" and U' forms) were investigated. The correction coefficients of the corresponding crystalline and amorphous diffraction peaks were given and the calculation formulae of the crystallinity of sPS T', T" and U' forms were deduced. The crystallinities of some sPS samples crystallized sufficiently at different temperatures obtained from calculation using the formulae and by DSC experiments were compared to be consistent with each other.
According to the theory of wide angle X-ray diffractometry, the graphic multi-peak resolution results of WAXD patterns of the various crystal forms of syndiotactic polystyrene(sPS)(T', T" and U' forms) were investigated. The correction coefficients of the corresponding crystalline and amorphous diffraction peaks were given and the calculation formulae of the crystallinity of sPS T', T" and U' forms were deduced. The crystallinities of some sPS samples crystallized sufficiently at different temperatures obtained from calculation using the formulae and by DSC experiments were compared to be consistent with each other.
2002, 19(9): 842-846
Abstract:
Two cobalt(Ⅲ) complexes of isonitrosoacetylacetone and its Schiff base isonitroso acetylacetone-N-arylimine, CoCl(p-ClC6H4-IAI)(IAI=isonitrosoacetylacetoneimino)(IAA)(p-ClC6H4NH2)(1) and CoCl(o-BrC6H4-IAI)(IAA)(o-BrC6H4NH2)(2), were prepared. Their spectral properties and structures were characterized by IR, Raman spectroscopy and XRD. The complex 1 crystallizes in monoclinic, with space group P21/n, a=1.6111(3) nm, b=1.3456(3) nm, c=2.3953(5) nm, U=91.42(3)°, Z=8, F(000)=2.400, _=10.10 cm-1. The final R=0.0731 for 5120 observed reflections with I≥2e(I). The complex 2 crystallizes in triclinic, with space group P1, a=0.9511(2) nm, b=0.953 8(2) nm, c=1.5687(3) nm, T=77.45(3)°, U=86.08(3)°, V=64.71(3)°, Z=2, F(000)=672, _=40.14 cm-1. The final R1 is 0.060.1 for 4207 observed reflections with I≥2σ(I). The geometry around the Co(Ⅲ) ions in both complexes has a distorted octahedral ClN4O coordination composed of imino-nitrogen and oximo-nitrogen from the Schiff base ligand aryl-IAI-, keto-oxygen and oximo-nitrogen from the ligand IAI-, amino-nitrogen from substituted aniline and chlorine anion.
Two cobalt(Ⅲ) complexes of isonitrosoacetylacetone and its Schiff base isonitroso acetylacetone-N-arylimine, CoCl(p-ClC6H4-IAI)(IAI=isonitrosoacetylacetoneimino)(IAA)(p-ClC6H4NH2)(1) and CoCl(o-BrC6H4-IAI)(IAA)(o-BrC6H4NH2)(2), were prepared. Their spectral properties and structures were characterized by IR, Raman spectroscopy and XRD. The complex 1 crystallizes in monoclinic, with space group P21/n, a=1.6111(3) nm, b=1.3456(3) nm, c=2.3953(5) nm, U=91.42(3)°, Z=8, F(000)=2.400, _=10.10 cm-1. The final R=0.0731 for 5120 observed reflections with I≥2e(I). The complex 2 crystallizes in triclinic, with space group P1, a=0.9511(2) nm, b=0.953 8(2) nm, c=1.5687(3) nm, T=77.45(3)°, U=86.08(3)°, V=64.71(3)°, Z=2, F(000)=672, _=40.14 cm-1. The final R1 is 0.060.1 for 4207 observed reflections with I≥2σ(I). The geometry around the Co(Ⅲ) ions in both complexes has a distorted octahedral ClN4O coordination composed of imino-nitrogen and oximo-nitrogen from the Schiff base ligand aryl-IAI-, keto-oxygen and oximo-nitrogen from the ligand IAI-, amino-nitrogen from substituted aniline and chlorine anion.
2002, 19(9): 847-851
Abstract:
A novel method for synthesis of briged bis-tetrathiafulvalenes has ben proposed. 2,3-Bis(2-cyanoethylthio)-6,7-(1,3-propylidenedithio)tetrathiafulvalene(5) was reacted with sodium methoxide to give monothiolate of tetrathiafulvalene(6), which on reacting with p-chloroxylene afforded a monobridged bis-tetrathiafulvalene(7). Deprotection and alkylation of (7) yielded two-bridged bis-tetrathiafulvalene(8). In cyclic voltammograms of both compound(7) and (8) there were two oxidation-reduction peaks. Their UV-Vis spectral absorbances were also found intensified.
A novel method for synthesis of briged bis-tetrathiafulvalenes has ben proposed. 2,3-Bis(2-cyanoethylthio)-6,7-(1,3-propylidenedithio)tetrathiafulvalene(5) was reacted with sodium methoxide to give monothiolate of tetrathiafulvalene(6), which on reacting with p-chloroxylene afforded a monobridged bis-tetrathiafulvalene(7). Deprotection and alkylation of (7) yielded two-bridged bis-tetrathiafulvalene(8). In cyclic voltammograms of both compound(7) and (8) there were two oxidation-reduction peaks. Their UV-Vis spectral absorbances were also found intensified.
2002, 19(9): 852-857
Abstract:
A charge-transfer complex, [(HOCH2CH2)2NH2]8·[SiW12O40]2·H2O, comprised of herteropoly acid (H4SiW12O40) and an organic substrate diethanolamine has been synthesized and characterized. Colorless crystals of the title compound were obtained from 0.1 mol/L HCl solution. Spectral data support the presence of a sizable electronic interaction between the organic substrate and the inorganic anion in the solid complex. It is strongly photosensitive under illumination of sunlight, resulting in charge-transfer in oxidation of diethanolamine and reduction of poly-oxometalate. The crystal of the title compund belongs to triclinic, space group P1, with a=1.3532(3) nm, b=1.9233(4) nm, c=2.0472(4) nm, T=89.28(3)°, U=85.49(3)°, V=82.99(3)°, Z=2, V=5.2754 nm3, _=26.188 mm-1 and F(000)=5 844.
A charge-transfer complex, [(HOCH2CH2)2NH2]8·[SiW12O40]2·H2O, comprised of herteropoly acid (H4SiW12O40) and an organic substrate diethanolamine has been synthesized and characterized. Colorless crystals of the title compound were obtained from 0.1 mol/L HCl solution. Spectral data support the presence of a sizable electronic interaction between the organic substrate and the inorganic anion in the solid complex. It is strongly photosensitive under illumination of sunlight, resulting in charge-transfer in oxidation of diethanolamine and reduction of poly-oxometalate. The crystal of the title compund belongs to triclinic, space group P1, with a=1.3532(3) nm, b=1.9233(4) nm, c=2.0472(4) nm, T=89.28(3)°, U=85.49(3)°, V=82.99(3)°, Z=2, V=5.2754 nm3, _=26.188 mm-1 and F(000)=5 844.
2002, 19(9): 858-861
Abstract:
A novel starch derivative——3,5-dinitrobenzoic acid ester of starch(DNBZ-ST) with different degree of substitution(DS) was prepared by reaction of starch with 3,5-dinitrobenzoyl chloride. The structures of products were characterized by FTIR, elemental analysis, 13C NMR and TG. The best reaction conditions were given. The DNBZ-ST has a good adsorption property for creatinine. The highest adsorption capacity was 25.0 mg creatinine per gram of DNBZ-ST(DS=2.09) at 37℃, pH=7 and creatinine concentration in solution of 100 mg/L.
A novel starch derivative——3,5-dinitrobenzoic acid ester of starch(DNBZ-ST) with different degree of substitution(DS) was prepared by reaction of starch with 3,5-dinitrobenzoyl chloride. The structures of products were characterized by FTIR, elemental analysis, 13C NMR and TG. The best reaction conditions were given. The DNBZ-ST has a good adsorption property for creatinine. The highest adsorption capacity was 25.0 mg creatinine per gram of DNBZ-ST(DS=2.09) at 37℃, pH=7 and creatinine concentration in solution of 100 mg/L.
2002, 19(9): 862-865
Abstract:
Papain was immobilized on poly(chitosan-co-acrylonitrile). The properties of immobilized enzyme such as Michaels constant, thermal stability and half-working life were studied. The results showed that the matrix could greatly adsorb papain with thermal stability increased. The optimum immobilization temperature was 70℃. After treatment at 70℃ for 9 h, 91% activity of the immobilized papain was retained. In comparison with native enzyme the thermal stability of immobilized papain on poly(chitosan-co-acrylonitrile) was improved considerably. After at storage 4℃ for 70 d, no turbidness was observed in beer treated with poly(chitosan-co-acrylonitrile) immobilized papain.
Papain was immobilized on poly(chitosan-co-acrylonitrile). The properties of immobilized enzyme such as Michaels constant, thermal stability and half-working life were studied. The results showed that the matrix could greatly adsorb papain with thermal stability increased. The optimum immobilization temperature was 70℃. After treatment at 70℃ for 9 h, 91% activity of the immobilized papain was retained. In comparison with native enzyme the thermal stability of immobilized papain on poly(chitosan-co-acrylonitrile) was improved considerably. After at storage 4℃ for 70 d, no turbidness was observed in beer treated with poly(chitosan-co-acrylonitrile) immobilized papain.
2002, 19(9): 866-869
Abstract:
The interactions between anionic surfactants(sodium laurate(C11H23COONa), sodium dodecyl sulfonate(C12AS)) and polyacrymide have been investigated by measurements of the reduced viscosity and ultra-violet spectra of the polymeric solutions. The results showed that in neutral and weak acid solutions PAM formed an aggregate with C11H23COONa behaved as a polyelectrolyte through hydrogen bonding and there was a large amount of charges in the PAM main chain caused by aggregate. However, PAM-C12AS aggregate was formed through dipolar interactions only in the case when the concentration of C12AS was higher than critical micelle concentration.
The interactions between anionic surfactants(sodium laurate(C11H23COONa), sodium dodecyl sulfonate(C12AS)) and polyacrymide have been investigated by measurements of the reduced viscosity and ultra-violet spectra of the polymeric solutions. The results showed that in neutral and weak acid solutions PAM formed an aggregate with C11H23COONa behaved as a polyelectrolyte through hydrogen bonding and there was a large amount of charges in the PAM main chain caused by aggregate. However, PAM-C12AS aggregate was formed through dipolar interactions only in the case when the concentration of C12AS was higher than critical micelle concentration.
2002, 19(9): 870-873
Abstract:
Sixteen O-substituted aryl-O-methyl-O-propargyl thiophosphates were synthesized via tandem reaction in dichloromethane by PTC in the presence of triethyl ammonium chloride (TEBAC) and/or tetrabutyl ammonium bromide(TBAB) and triethylene diamine. At condition of m(TEBAC):m(TBAB)=1:1, pH=9~10, 25~35℃, 2.5~3 h thiophosphates were obtained in yields of 60%~97%. The structures of the compounds were characterized by elemental analysis, IR and 1H NMR spectroscopy. The compound Ⅲ5(O-4 nitrophenyl-O-methyl-O-propargyl thiophosphate) showed an excellent insecticidal activity against aphid nearly 100% in dosage of 0.025%.
Sixteen O-substituted aryl-O-methyl-O-propargyl thiophosphates were synthesized via tandem reaction in dichloromethane by PTC in the presence of triethyl ammonium chloride (TEBAC) and/or tetrabutyl ammonium bromide(TBAB) and triethylene diamine. At condition of m(TEBAC):m(TBAB)=1:1, pH=9~10, 25~35℃, 2.5~3 h thiophosphates were obtained in yields of 60%~97%. The structures of the compounds were characterized by elemental analysis, IR and 1H NMR spectroscopy. The compound Ⅲ5(O-4 nitrophenyl-O-methyl-O-propargyl thiophosphate) showed an excellent insecticidal activity against aphid nearly 100% in dosage of 0.025%.
2002, 19(9): 874-877
Abstract:
Poly(silicic acid) was obtained by the hydrolysis of sodium silicate in hydrochloric acid. Poly(methyl methacrylate) silica hybrids were prepared through polymerization, condensation and sol-gel processes of the mixture of methyl methacrylate, poly(silicic acid) and a small amount of coupling agent methacryloxylpropyl trimethoxy siliane in tetrahydrofuran. FTIR, SEM and TEM investigations on the structure of the hybrids showed that there are -C-Si-O- covalent bonds between organic and inorganic moieties in the hybrids. The TGA and DSC analyses revealed the good compatibility between the inorganic and organic moieties and no phase separation was observed. The hybrids have transparency nearly 80% with thermal resistance and glass temperature much higher than that of pure PMMA.
Poly(silicic acid) was obtained by the hydrolysis of sodium silicate in hydrochloric acid. Poly(methyl methacrylate) silica hybrids were prepared through polymerization, condensation and sol-gel processes of the mixture of methyl methacrylate, poly(silicic acid) and a small amount of coupling agent methacryloxylpropyl trimethoxy siliane in tetrahydrofuran. FTIR, SEM and TEM investigations on the structure of the hybrids showed that there are -C-Si-O- covalent bonds between organic and inorganic moieties in the hybrids. The TGA and DSC analyses revealed the good compatibility between the inorganic and organic moieties and no phase separation was observed. The hybrids have transparency nearly 80% with thermal resistance and glass temperature much higher than that of pure PMMA.
2002, 19(9): 878-881
Abstract:
The cysteine(Cys) and thiourea(Tu) complexes with antimony and arsenic trihalide have been synthesized by solid phase reaction. The compositions and structures of the complexes have been characterized by elemental analysis, infrared spectra and X-ray powder diffraction. The complexes have compositions of ML3X3(M=As,Sb; L=Cys,Tu; X=I,Cl). They are stable at room temperature, nonhygroscopic and slightly soluble in water. The results indicate that the sulphur in cysteine, nitrogen in thiourea and chlorine or iodine atoms are coordinated with trivalent arsenic or antimony ion. The coordination numbers of arsenic and antimony ion in the complexes are six. The crystal of the complexes belongs to monoclinic system with a=1.1743 nm, b=0.6945 nm, c=1.6822 nm, U=95.28° for As(Cys)3I3; a=1.1119 nm, b=1.9030 nm, c=1.5410 nm, U=94.77° for As(Tu)3I3; a=1.2051 nm, b=0.6792 nm, c=1.6850 nm, U=95.79° for Sb(Cys)3Cl3; and a=1.2343 nm, b=1.6585 nm, c=1.9252 nm, U=96.46° for Sb(Tu)3Cl3, respectively.
The cysteine(Cys) and thiourea(Tu) complexes with antimony and arsenic trihalide have been synthesized by solid phase reaction. The compositions and structures of the complexes have been characterized by elemental analysis, infrared spectra and X-ray powder diffraction. The complexes have compositions of ML3X3(M=As,Sb; L=Cys,Tu; X=I,Cl). They are stable at room temperature, nonhygroscopic and slightly soluble in water. The results indicate that the sulphur in cysteine, nitrogen in thiourea and chlorine or iodine atoms are coordinated with trivalent arsenic or antimony ion. The coordination numbers of arsenic and antimony ion in the complexes are six. The crystal of the complexes belongs to monoclinic system with a=1.1743 nm, b=0.6945 nm, c=1.6822 nm, U=95.28° for As(Cys)3I3; a=1.1119 nm, b=1.9030 nm, c=1.5410 nm, U=94.77° for As(Tu)3I3; a=1.2051 nm, b=0.6792 nm, c=1.6850 nm, U=95.79° for Sb(Cys)3Cl3; and a=1.2343 nm, b=1.6585 nm, c=1.9252 nm, U=96.46° for Sb(Tu)3Cl3, respectively.
2002, 19(9): 882-885
Abstract:
TiO2 sol was prepared in NMP by a sol-gel method using tetrabutyl titanate(TBT) as a precursor and acetic acid as a stabilizer. The effects of reaction conditions e.g. the way of adding water, mole ratio of water to TBT, volume ratio of NMP to TBT, pH value and temperature on the sol-gel process have been investigated. The results showed that at room temperature when the mole ratio of water to TBT was 3~4, the volume ratio of NMP to TBT was 2~3 and the value of pH was 2~4 a stable and transparent TiO2 sol could be obtained.
TiO2 sol was prepared in NMP by a sol-gel method using tetrabutyl titanate(TBT) as a precursor and acetic acid as a stabilizer. The effects of reaction conditions e.g. the way of adding water, mole ratio of water to TBT, volume ratio of NMP to TBT, pH value and temperature on the sol-gel process have been investigated. The results showed that at room temperature when the mole ratio of water to TBT was 3~4, the volume ratio of NMP to TBT was 2~3 and the value of pH was 2~4 a stable and transparent TiO2 sol could be obtained.
2002, 19(9): 886-889
Abstract:
Using an optical capillary rheometer, the rheological behavior of polyacrylamide(PAM) solutions with different salt concentrations, flowing through capillaries of different diameter(25~150 μm), lengths(40.6~100.1 mm) as well as with or without internal coated-surface at extremely low shear rates have been studied. The results showed that the marked differences rheological behavior of PAM solutions flowing through capillaries of micron diameter are due to the geometrical dimension and nature of the internal wall surface of the capillaries, while the rheological differences occurved in salt-containing PAM solution are due to the electrical property of the solution. Hence, greater internal diameter of the pores and channels and shorter lengths of the channels in the porous media of the oil field are favorable to the oil recovery. And decreasing concentration of sodium ions of PAM solutions could increase the interaction between PAM solutions and oil membrane also favorable to oil recovery.
Using an optical capillary rheometer, the rheological behavior of polyacrylamide(PAM) solutions with different salt concentrations, flowing through capillaries of different diameter(25~150 μm), lengths(40.6~100.1 mm) as well as with or without internal coated-surface at extremely low shear rates have been studied. The results showed that the marked differences rheological behavior of PAM solutions flowing through capillaries of micron diameter are due to the geometrical dimension and nature of the internal wall surface of the capillaries, while the rheological differences occurved in salt-containing PAM solution are due to the electrical property of the solution. Hence, greater internal diameter of the pores and channels and shorter lengths of the channels in the porous media of the oil field are favorable to the oil recovery. And decreasing concentration of sodium ions of PAM solutions could increase the interaction between PAM solutions and oil membrane also favorable to oil recovery.
2002, 19(9): 890-893
Abstract:
(2-Hydroxyl-3-butoxyl) propyl-hydroxylpropylchitosan(HBP-HPCHS) was synthesized from chitosan(CHS) by hydrophilic and hydrophobic modification and its application property has been studied. The title compound with surfacetension of 35 mN/m shows good surface activity and ability to generate and stabilize foam in the solution. It can form stable emulsion with liquid paraffin, and has good moisture absorbency and moisture retention ability as hyaluronic acid.
(2-Hydroxyl-3-butoxyl) propyl-hydroxylpropylchitosan(HBP-HPCHS) was synthesized from chitosan(CHS) by hydrophilic and hydrophobic modification and its application property has been studied. The title compound with surfacetension of 35 mN/m shows good surface activity and ability to generate and stabilize foam in the solution. It can form stable emulsion with liquid paraffin, and has good moisture absorbency and moisture retention ability as hyaluronic acid.
2002, 19(9): 894-897
Abstract:
Based on the fact that tyrosine molecule contains a phenyl ring and a phenolic hydroxyl group, a polymeric adsorbent-macroporous acetyl aminomethylene polystyrene resin, which was expected to form hydrogen bonding and hydrophobic interaction with tyrosine but not with cystine, was synthesized. The results indicated that tyrosine had high retention on a column packed with the adsorbent while cystine had no retention. By comparing the retentions of cystine, tyrosine and phenylalanine on columns packed with macroporous acetyl aminomethylene polystyrene resin, macro porous polystyrene resin and polyacrylamide resin, respectively, it was concluded that there are hydrophobic interaction and hydrogen bonding between tyrosine and macroporous acetyl aminomethylene polystyrene resin and the two interactions acted synergistically. From 0.4 g mixture of cystine and tyrosine, an industrial byproduct of amino acids from hydrolysis of proteins on a column(250 mm×10 mm, I.D.) packed with macroporous acetyl aminomethylene polystyrene resin 0.2 g of pure cystine and 0.12 g of pure tyrosine were obtained, respectively.
Based on the fact that tyrosine molecule contains a phenyl ring and a phenolic hydroxyl group, a polymeric adsorbent-macroporous acetyl aminomethylene polystyrene resin, which was expected to form hydrogen bonding and hydrophobic interaction with tyrosine but not with cystine, was synthesized. The results indicated that tyrosine had high retention on a column packed with the adsorbent while cystine had no retention. By comparing the retentions of cystine, tyrosine and phenylalanine on columns packed with macroporous acetyl aminomethylene polystyrene resin, macro porous polystyrene resin and polyacrylamide resin, respectively, it was concluded that there are hydrophobic interaction and hydrogen bonding between tyrosine and macroporous acetyl aminomethylene polystyrene resin and the two interactions acted synergistically. From 0.4 g mixture of cystine and tyrosine, an industrial byproduct of amino acids from hydrolysis of proteins on a column(250 mm×10 mm, I.D.) packed with macroporous acetyl aminomethylene polystyrene resin 0.2 g of pure cystine and 0.12 g of pure tyrosine were obtained, respectively.
2002, 19(9): 898-901
Abstract:
Nanosized TiO2 and Y-doped TiO2 were synthesized from Ti(OC4H9)4 and Y(NO3)3 by a sol-gel method. The structure, size, appearance, and the polymorphic transition between anatase and rutile of TiO2 crystal types were examined by XRD, TEM, TG-DTA. The results indicate the average particle size of TiO2 crystal is about 30 nm and the doped Y prevents the transition of TiO2 from anatase to rutile.
Nanosized TiO2 and Y-doped TiO2 were synthesized from Ti(OC4H9)4 and Y(NO3)3 by a sol-gel method. The structure, size, appearance, and the polymorphic transition between anatase and rutile of TiO2 crystal types were examined by XRD, TEM, TG-DTA. The results indicate the average particle size of TiO2 crystal is about 30 nm and the doped Y prevents the transition of TiO2 from anatase to rutile.
2002, 19(9): 902-904
Abstract:
The distribution of Fe and Mn oxides in surface coatings developed in natural waters in Jilin province of China has been investigated. The results indicate that the amounts of iron oxides and manganese oxides differ significantly with the former being much higher and there is a correlative relationship between contents of Fe and Mn oxides and depths at which surface coatings were collected. The same phenumenon was also observed between contents of Fe and Mn oxides and developing period of surface coatings.
The distribution of Fe and Mn oxides in surface coatings developed in natural waters in Jilin province of China has been investigated. The results indicate that the amounts of iron oxides and manganese oxides differ significantly with the former being much higher and there is a correlative relationship between contents of Fe and Mn oxides and depths at which surface coatings were collected. The same phenumenon was also observed between contents of Fe and Mn oxides and developing period of surface coatings.
2002, 19(9): 905-907
Abstract:
p-Methylbenzaldehyde was prepared in yield of 75% by addition hydrolysis reactions of Grignard agent p-CH3C6H4MgBr with 1,3-dimethylbenzimidazolium iodide. It is a biomimetic synthetic method. The reaction was carried out under mild and convenient condition. The addition reaction and hydrolysis were of "one-pot" reaction, without necessity of isolating benzimidazolidine. The hydrolysis reaction was carried out in 5% HCl solution at 30~40℃. The addition-hydrolysis reaction mechanism has been discussed briefly.
p-Methylbenzaldehyde was prepared in yield of 75% by addition hydrolysis reactions of Grignard agent p-CH3C6H4MgBr with 1,3-dimethylbenzimidazolium iodide. It is a biomimetic synthetic method. The reaction was carried out under mild and convenient condition. The addition reaction and hydrolysis were of "one-pot" reaction, without necessity of isolating benzimidazolidine. The hydrolysis reaction was carried out in 5% HCl solution at 30~40℃. The addition-hydrolysis reaction mechanism has been discussed briefly.
2002, 19(9): 908-910
Abstract:
The photo- and thermo-decomposition kinetics of diphenylamine diazoresin in water, ethanol-water and methanol-water has been investigated by spectrophotometry. The velocity of photo-decomposition is higher than that of thermo-decomposition in the same solvent.
The photo- and thermo-decomposition kinetics of diphenylamine diazoresin in water, ethanol-water and methanol-water has been investigated by spectrophotometry. The velocity of photo-decomposition is higher than that of thermo-decomposition in the same solvent.
2002, 19(9): 911-913
Abstract:
The effect of polarization time on the schiff base self-assembled monolayer containing hydrosulfo group has been investigated by CV and ac impedance measurements. The results showed that, when the potential of -0.87 V(vs. SCE) was applied on the monolayer, the electrochemical charge transfer resistance Rct originated from the reduction of C=N increased with the polarization time within 4 min and then decreased. This phenomenon may be related to the relationship between the C=N group and the structure of the Schiff base self-assembled monolayer.
The effect of polarization time on the schiff base self-assembled monolayer containing hydrosulfo group has been investigated by CV and ac impedance measurements. The results showed that, when the potential of -0.87 V(vs. SCE) was applied on the monolayer, the electrochemical charge transfer resistance Rct originated from the reduction of C=N increased with the polarization time within 4 min and then decreased. This phenomenon may be related to the relationship between the C=N group and the structure of the Schiff base self-assembled monolayer.
2002, 19(9): 914-916
Abstract:
The nano-TiO2/Poly(butyl acrylate) composite film was prepared by in-situ polymerization initiated by UV illustration and characterized by FTIR, XPS and HRTEM. The friction behavior of the composite film in sliding against AISI-52100 steel was examined on a DF-PM friction coefficient measurement apparatus. The results indicated that the TiO2 nanolines were dispersed in the poly(butyl acrylate) network. The film exhibites a good antiwear property.
The nano-TiO2/Poly(butyl acrylate) composite film was prepared by in-situ polymerization initiated by UV illustration and characterized by FTIR, XPS and HRTEM. The friction behavior of the composite film in sliding against AISI-52100 steel was examined on a DF-PM friction coefficient measurement apparatus. The results indicated that the TiO2 nanolines were dispersed in the poly(butyl acrylate) network. The film exhibites a good antiwear property.
2002, 19(9): 917-918
Abstract:
2-Amino-4,6-dimethoxypyrimidine(AMP) was synthesized using benzyltriethyl ammonium chloride(BTEA) as a catalyst in yield of 87.5%. A solid complex Co(AMP)2Cl2 was obtained by refluxing AMP with CoCl2 in ethanol. The composition of the complex was determined by chemical and elemental analyses. The structure of the complex and sp3 d2 of the hybridization type of Co2+ were estimated by IR, XPS and 1H NMR.
2-Amino-4,6-dimethoxypyrimidine(AMP) was synthesized using benzyltriethyl ammonium chloride(BTEA) as a catalyst in yield of 87.5%. A solid complex Co(AMP)2Cl2 was obtained by refluxing AMP with CoCl2 in ethanol. The composition of the complex was determined by chemical and elemental analyses. The structure of the complex and sp3 d2 of the hybridization type of Co2+ were estimated by IR, XPS and 1H NMR.
