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2009 Volume 20 Issue 4
2009, 20(4): 379-382
doi: 10.1016/j.cclet.2008.12.040
Abstract:
A novel polyethylene glycol (PEG)-200-based dicationic acidic ionic liquid (PEG200-DAIL) was used to synthesize HMX from DPT by nitrolysis with N2O5. It was found that either N2O5 or PEG200-DAIL could improve the yield. Furthermore, the combined use of PEG200-DAIL and N2O5 could increase the yield of HMX to 64% with the used quantity of HNO3 decreased dramatically.
A novel polyethylene glycol (PEG)-200-based dicationic acidic ionic liquid (PEG200-DAIL) was used to synthesize HMX from DPT by nitrolysis with N2O5. It was found that either N2O5 or PEG200-DAIL could improve the yield. Furthermore, the combined use of PEG200-DAIL and N2O5 could increase the yield of HMX to 64% with the used quantity of HNO3 decreased dramatically.
2009, 20(4): 383-386
doi: 10.1016/j.cclet.2008.12.018
Abstract:
An efficient and direct procedure has been developed for the preparation of amidoalkyl naphthols by a one-pot condensation of aryl aldehydes, 2-naphthol and urea or amides, in the presence of wet-cyanuric chloride (wet-TCT) as a catalyst. The reactions were carried out under solvent-free media. The present methodology offers several advantages such as excellent yields, simple procedure and eco-friendly reaction condition.
An efficient and direct procedure has been developed for the preparation of amidoalkyl naphthols by a one-pot condensation of aryl aldehydes, 2-naphthol and urea or amides, in the presence of wet-cyanuric chloride (wet-TCT) as a catalyst. The reactions were carried out under solvent-free media. The present methodology offers several advantages such as excellent yields, simple procedure and eco-friendly reaction condition.
2009, 20(4): 387-390
doi: 10.1016/j.cclet.2008.12.021
Abstract:
Promoted and mediated by an ionic liquid-[bmim][BF4], fused pyrans or arylbis(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)methanes were efficiently and selectively prepared from the reaction of aldehyde and 4-hydroxy-6-methyl-2-oxo-pyran with or without acetic anhydride. By using these novel procedures, pyrimidine nucleoside-fused pyran and arylbis(pyranon-3-yl)methane hybrids with potential biological activities were constructed.
Promoted and mediated by an ionic liquid-[bmim][BF4], fused pyrans or arylbis(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)methanes were efficiently and selectively prepared from the reaction of aldehyde and 4-hydroxy-6-methyl-2-oxo-pyran with or without acetic anhydride. By using these novel procedures, pyrimidine nucleoside-fused pyran and arylbis(pyranon-3-yl)methane hybrids with potential biological activities were constructed.
2009, 20(4): 391-392
doi: 10.1016/j.cclet.2008.11.011
Abstract:
A new derivative of geldanamycin was synthesized by introducing the 6-cinnamamido-hexyl-amino group into the 17-site of geldanamycin, a heat shock protein 90(Hsp90) inhibitor, to obtain 17-(6-cinnamamido-hexylamino)-17-demethoxygel-danamycin (CNDG). Its in vitro and in vivo antitumor effects were evaluated by MTT assay and xenograft in nude mice.
A new derivative of geldanamycin was synthesized by introducing the 6-cinnamamido-hexyl-amino group into the 17-site of geldanamycin, a heat shock protein 90(Hsp90) inhibitor, to obtain 17-(6-cinnamamido-hexylamino)-17-demethoxygel-danamycin (CNDG). Its in vitro and in vivo antitumor effects were evaluated by MTT assay and xenograft in nude mice.
2009, 20(4): 393-396
doi: 10.1016/j.cclet.2008.11.022
Abstract:
Pyridinium bromochromate has been found to be a highly efficient and selective reagent for the α-monobromination of 1,3-diketones and β-keto-esters in the absence of base, Lewis acid, or other catalyst. The products were formed in high to excellent yields under mild reaction conditions and in short reaction times
Pyridinium bromochromate has been found to be a highly efficient and selective reagent for the α-monobromination of 1,3-diketones and β-keto-esters in the absence of base, Lewis acid, or other catalyst. The products were formed in high to excellent yields under mild reaction conditions and in short reaction times
2009, 20(4): 397-400
doi: 10.1016/j.cclet.2008.11.023
Abstract:
An efficient and simple method for the synthesis of new chiral aromatic amide molecular tweezers by irradiation with microwave under solvent-free conditions has been developed. Its main advantages are short reaction times, good conversions and the environmentally friendly nature of the process.
An efficient and simple method for the synthesis of new chiral aromatic amide molecular tweezers by irradiation with microwave under solvent-free conditions has been developed. Its main advantages are short reaction times, good conversions and the environmentally friendly nature of the process.
2009, 20(4): 401-403
doi: 10.1016/j.cclet.2008.12.036
Abstract:
Under microwave irradiation, the corresponding hydroxycyclopentenones were prepared in high yields by the cross-aldol reactions of benzil with various ketones. When the reactions were performed in various solvents under classical heating for a long time, they produced the products in relatively low yields.
Under microwave irradiation, the corresponding hydroxycyclopentenones were prepared in high yields by the cross-aldol reactions of benzil with various ketones. When the reactions were performed in various solvents under classical heating for a long time, they produced the products in relatively low yields.
2009, 20(4): 404-406
doi: 10.1016/j.cclet.2008.12.009
Abstract:
A series of 4H-[1,2,5]oxadiazolo[3,4-d]pyrimidine-5,7-dione 1-oxide nucleosides was designed, synthesized and evaluated against vesicular stomatitis virus (VSV) inWish cell. The antiviral activities of all compounds were stronger than those of acyclovir,while their toxicities were similar to those of acyclovir.
A series of 4H-[1,2,5]oxadiazolo[3,4-d]pyrimidine-5,7-dione 1-oxide nucleosides was designed, synthesized and evaluated against vesicular stomatitis virus (VSV) inWish cell. The antiviral activities of all compounds were stronger than those of acyclovir,while their toxicities were similar to those of acyclovir.
2009, 20(4): 407-410
doi: 10.1016/j.cclet.2008.12.030
Abstract:
β-Amino esters were synthesized via ZnCl2-catalyzed Mannich-type reaction of imines and malonate esters under solvent-free conditions in 6 min. The β-amino ester was converted into the corresponding aspartic acid derivatives.
β-Amino esters were synthesized via ZnCl2-catalyzed Mannich-type reaction of imines and malonate esters under solvent-free conditions in 6 min. The β-amino ester was converted into the corresponding aspartic acid derivatives.
2009, 20(4): 411-414
doi: 10.1016/j.cclet.2008.11.030
Abstract:
A novel series of quaternary ammonium cationic derivatives based on tetrapyridyl-porphyrin was synthesized. All the compounds were evaluated for their in vitro antibacterial activities against S. aureus, E. coli and P. aeruginosa, and antifungal activities against C. albicans, where microorganisms were exposed and unexposed to the irradiation. The results revealed that some of these compounds, especially, 3a and 4a displayed satisfactory antibacterial activity against Gram-positive bacteria S. aureus and moderate antifungal activity against C. albicans. Unfortunately, Gram-negative bacteria P. aeruginasa was resistant to all compounds. The antimicrobial activity was found to be sensitive to the functional groups attached on the aromatic ring and the complex metal in the porphyrin ring, and decreased with the increase of electron-withdrawing capability of the functional groups. These preliminary results suggested that the remarkable antibacterial efficiency against S. aureus makes these substances promising antimicrobial agents.
A novel series of quaternary ammonium cationic derivatives based on tetrapyridyl-porphyrin was synthesized. All the compounds were evaluated for their in vitro antibacterial activities against S. aureus, E. coli and P. aeruginosa, and antifungal activities against C. albicans, where microorganisms were exposed and unexposed to the irradiation. The results revealed that some of these compounds, especially, 3a and 4a displayed satisfactory antibacterial activity against Gram-positive bacteria S. aureus and moderate antifungal activity against C. albicans. Unfortunately, Gram-negative bacteria P. aeruginasa was resistant to all compounds. The antimicrobial activity was found to be sensitive to the functional groups attached on the aromatic ring and the complex metal in the porphyrin ring, and decreased with the increase of electron-withdrawing capability of the functional groups. These preliminary results suggested that the remarkable antibacterial efficiency against S. aureus makes these substances promising antimicrobial agents.
2009, 20(4): 415-419
doi: 10.1016/j.cclet.2008.12.044
Abstract:
A wide variety of secondary amines are chemoselectively subjected to N-nitrosation reaction with treatment of citric acid and NaNO2 in the presence of wet SiO2 (50%, w/w) in dichloromethane at room temperatture under heterogeneous conditions. The N-nitrosation method is very simple and products can be easily isolated with good to high yields.
A wide variety of secondary amines are chemoselectively subjected to N-nitrosation reaction with treatment of citric acid and NaNO2 in the presence of wet SiO2 (50%, w/w) in dichloromethane at room temperatture under heterogeneous conditions. The N-nitrosation method is very simple and products can be easily isolated with good to high yields.
2009, 20(4): 420-422
doi: 10.1016/j.cclet.2008.12.012
Abstract:
A series of novel 2,4-diamino-pteridines (9a-l) were synthesized and evaluated as inhibitors of inducible nitric oxide synthase (iNOS) in vitro. It was found that 9a, 9d, 9e, 9h, 9i and 9l showed potent inhibitory activities similar to that of methotrexate (MTX),while the activities of 9b, 9c, 9f, 9g, 9j and 9k are stronger than MTX.
A series of novel 2,4-diamino-pteridines (9a-l) were synthesized and evaluated as inhibitors of inducible nitric oxide synthase (iNOS) in vitro. It was found that 9a, 9d, 9e, 9h, 9i and 9l showed potent inhibitory activities similar to that of methotrexate (MTX),while the activities of 9b, 9c, 9f, 9g, 9j and 9k are stronger than MTX.
2009, 20(4): 423-426
doi: 10.1016/j.cclet.2008.12.046
Abstract:
AYb(OTf)3-catalyzed approach for the synthesis of pyrroles under solvent-free conditions was achieved, which could afford the desired products with yields ranged from moderate to excellent.
AYb(OTf)3-catalyzed approach for the synthesis of pyrroles under solvent-free conditions was achieved, which could afford the desired products with yields ranged from moderate to excellent.
2009, 20(4): 427-430
doi: 10.1016/j.cclet.2008.12.013
Abstract:
Eight novel heterocycle-substituted dihydropyrazole derivatives were synthesized and characterized by ESI-MS, 1H NMR and 13C NMR. All of the compounds have been screened for their antibacterial potential in vitro against Bacillus subtilis,Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. The results show that compounds 9b, 9g and 9h displayed significant activity with MIC values in the range of 0.39-1.562 mg/mL against B. subtilis.
Eight novel heterocycle-substituted dihydropyrazole derivatives were synthesized and characterized by ESI-MS, 1H NMR and 13C NMR. All of the compounds have been screened for their antibacterial potential in vitro against Bacillus subtilis,Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. The results show that compounds 9b, 9g and 9h displayed significant activity with MIC values in the range of 0.39-1.562 mg/mL against B. subtilis.
2009, 20(4): 431-434
doi: 10.1016/j.cclet.2008.12.028
Abstract:
Two novel C-nor-B-homo aconane-type diterpenes 4 and 5, featuring a unique eight-membered ring system, were obtained by the treatment of C-nor-C19-diterpenoid alkaloid 3 with HNO2 in 8% and 21% yields, respectively. Structures of these two compounds were established based on the combination of spectroscopic data, including HRESIMS, 1D and 2D NMR data.A plausible mechanism for the formation of 4 and 5 is also presented.
Two novel C-nor-B-homo aconane-type diterpenes 4 and 5, featuring a unique eight-membered ring system, were obtained by the treatment of C-nor-C19-diterpenoid alkaloid 3 with HNO2 in 8% and 21% yields, respectively. Structures of these two compounds were established based on the combination of spectroscopic data, including HRESIMS, 1D and 2D NMR data.A plausible mechanism for the formation of 4 and 5 is also presented.
2009, 20(4): 435-438
doi: 10.1016/j.cclet.2008.12.027
Abstract:
Eight new brominated 2'(4')-nitro-3-hydroxy diphenyl ethers have been designed and synthesized. The structures of new compounds were confirmed by 1H NMR, IR and HRMS. The bioactivity tests showed that these compounds possessed antibacterial activities against the tested bacteria. These new compounds cannot be transformed into dioxins when they were manufactured and used.
Eight new brominated 2'(4')-nitro-3-hydroxy diphenyl ethers have been designed and synthesized. The structures of new compounds were confirmed by 1H NMR, IR and HRMS. The bioactivity tests showed that these compounds possessed antibacterial activities against the tested bacteria. These new compounds cannot be transformed into dioxins when they were manufactured and used.
2009, 20(4): 439-443
doi: 10.1016/j.cclet.2008.11.024
Abstract:
A variety of alcohols and phenols are efficiently acetylated with acetic anhydride in the presence of a catalytic amount of V(HSO4)3 in solution and under solvent free conditions. Mild reaction conditions, high yields of the products, easy procedure and selective acetylation of alcohols and phenols in the presence of amines and thiols are the main advantages of this procedure.
A variety of alcohols and phenols are efficiently acetylated with acetic anhydride in the presence of a catalytic amount of V(HSO4)3 in solution and under solvent free conditions. Mild reaction conditions, high yields of the products, easy procedure and selective acetylation of alcohols and phenols in the presence of amines and thiols are the main advantages of this procedure.
2009, 20(4): 444-446
doi: 10.1016/j.cclet.2008.12.039
Abstract:
A new cassane diterpenoid lactone was isolated from the seed of Caesalpinia minax. On the basis of spectral evidences, its structure was established as 12α-methoxyl, 5α, 14β-dihydroxy-1a, 6α, 7β-triacetoxycass-13(15)-en-16, 12-olide.
A new cassane diterpenoid lactone was isolated from the seed of Caesalpinia minax. On the basis of spectral evidences, its structure was established as 12α-methoxyl, 5α, 14β-dihydroxy-1a, 6α, 7β-triacetoxycass-13(15)-en-16, 12-olide.
2009, 20(4): 447-449
doi: 10.1016/j.cclet.2008.12.024
Abstract:
A new ceramide (1) was isolated from transgenic crown galls of Panax quinquefolium. The structure was elucidated as (2S, 3S,4R, 20E)-2-[(2'R)-2'-hydroxyl-palmitoyl-amino]-20-hexacosene-1, 3, 4-triol on the basis of spectroscopic and chemical methods.
A new ceramide (1) was isolated from transgenic crown galls of Panax quinquefolium. The structure was elucidated as (2S, 3S,4R, 20E)-2-[(2'R)-2'-hydroxyl-palmitoyl-amino]-20-hexacosene-1, 3, 4-triol on the basis of spectroscopic and chemical methods.
2009, 20(4): 450-452
doi: 10.1016/j.cclet.2008.12.043
Abstract:
A new cardenolide, toxicarioside E (1), was isolated from the latex of Antiaris toxicaria (Pers.) Lesch (Moraceae). Its structure was elucidated on the basis of spectral data and chemical evidence. Compound 1 showed significant cytotoxicity against K562 and SGC-7901 cell lines in vitro by MTT method with the IC50 value of 0.026 and 0.027μg/mL, respectively.
A new cardenolide, toxicarioside E (1), was isolated from the latex of Antiaris toxicaria (Pers.) Lesch (Moraceae). Its structure was elucidated on the basis of spectral data and chemical evidence. Compound 1 showed significant cytotoxicity against K562 and SGC-7901 cell lines in vitro by MTT method with the IC50 value of 0.026 and 0.027μg/mL, respectively.
2009, 20(4): 456-458
doi: 10.1016/j.cclet.2008.12.015
Abstract:
Two new bromoindole alkaloids have been isolated from the ethanolic extract of the red alga Laurencia similis. On the basis of chemical and spectroscopic methods (including 1D and 2D NMR technique), their structures have been elucidated as 2,2',5,5',6,6'-sixibromo-3, 3'-bi-1H-indole and 3, 5-dibromo-1-methylindole, respectively.
Two new bromoindole alkaloids have been isolated from the ethanolic extract of the red alga Laurencia similis. On the basis of chemical and spectroscopic methods (including 1D and 2D NMR technique), their structures have been elucidated as 2,2',5,5',6,6'-sixibromo-3, 3'-bi-1H-indole and 3, 5-dibromo-1-methylindole, respectively.
2009, 20(4): 459-461
doi: 10.1016/j.cclet.2008.12.038
Abstract:
Two new benzophenone glucosides were isolated from the 60% ethanol extract of the dried stems of Cratoxylum cochinchinense.The structures were elucidated as 3-O-β-D-glucopyranosyl-2',4,6'-trihydroxy-benzophenone and 3-O-β-D-glucopyranosyl-2',5,6'-trihydroxybenzophenone on the basis of spectral and chemical methods.
Two new benzophenone glucosides were isolated from the 60% ethanol extract of the dried stems of Cratoxylum cochinchinense.The structures were elucidated as 3-O-β-D-glucopyranosyl-2',4,6'-trihydroxy-benzophenone and 3-O-β-D-glucopyranosyl-2',5,6'-trihydroxybenzophenone on the basis of spectral and chemical methods.
2009, 20(4): 462-464
doi: 10.1016/j.cclet.2008.12.032
Abstract:
An modified laminar crystal sodium silicate (Al-SKS-6) was synthesized by spray drying and high temperature crystallization using sodium silicate as silicon source, Al atom as inorganic source and hexadecyltrimethy ammonium bromide (CTMAB) as the structure template. The hydrothermal stability of product was at least 1 h. The synthesized material was characterized by XRD and SEM. The results indicated that shape and intensity of XRD diffraction peak at 2θ took changes, but raw material δ phase crystal form kept unchanged, and assured high Ca2+ and Mg2+ binding capacity of the products. The Ca2+ and Mg2+ binding capacity of product is up to 380 mg Ca/g and 410mg Mg/g respectively. It was found that the hole of product became smaller and appeared rod structure based on SEM. The hydrothermal stability was increased due to the pillaring of Al atom.
An modified laminar crystal sodium silicate (Al-SKS-6) was synthesized by spray drying and high temperature crystallization using sodium silicate as silicon source, Al atom as inorganic source and hexadecyltrimethy ammonium bromide (CTMAB) as the structure template. The hydrothermal stability of product was at least 1 h. The synthesized material was characterized by XRD and SEM. The results indicated that shape and intensity of XRD diffraction peak at 2θ took changes, but raw material δ phase crystal form kept unchanged, and assured high Ca2+ and Mg2+ binding capacity of the products. The Ca2+ and Mg2+ binding capacity of product is up to 380 mg Ca/g and 410mg Mg/g respectively. It was found that the hole of product became smaller and appeared rod structure based on SEM. The hydrothermal stability was increased due to the pillaring of Al atom.
2009, 20(4): 465-468
doi: 10.1016/j.cclet.2008.12.017
Abstract:
Some reactions of R3SnM(CO)5 (M=Mn, Re) with CH3CN or pyridine were investigated to give complexes R3SnMn(CO)3LL'or R3SnMn(CO)4L by a facile mild method. X-ray diffractions analyses show that, in contrast to the phosphine ligand occupying in axial position, nitrogen ligands occupy equatorial position.
Some reactions of R3SnM(CO)5 (M=Mn, Re) with CH3CN or pyridine were investigated to give complexes R3SnMn(CO)3LL'or R3SnMn(CO)4L by a facile mild method. X-ray diffractions analyses show that, in contrast to the phosphine ligand occupying in axial position, nitrogen ligands occupy equatorial position.
2009, 20(4): 469-472
doi: 10.1016/j.cclet.2008.11.017
Abstract:
Silica-based monolithic column material was synthesized and an enrichment device was fabricated with the material by assembling the material inside a glass column. The enrichment device was applied for the determination of micro-carbaryl with near-infrared spectroscopy (NIRS). The aqueous solutions of carbaryl passed through the device and the carbaryl was enriched on the surface of the material where diffuse reflection NIR spectra were measured. These procedures of enrichment and measurement ensured to concentrate analytes for the measurement, so that the sensitivity of determination of NIRS could be improved. NIR spectra of carbaryl solutions (0.01-1.00μg mL-1), measured after the application of the enrichment device, were pretreated with multiplicative scatter correction (MSC) and regressed against the concentrations of the carbaryl solutions with partial least squares (PLS) method. The results showed that the minimum value of root-mean-square error of prediction (RMSEP) was 0.1771μg mL-1 when the number of latent variables was 3 of PLS regression. Therefore, the number of latent variables 3 was selected as the optimum value. RMSEP was not very low but acceptable considering that NIRS is commonly used in macro amount analysis and it is quite difficult for NIRS to determine micro amount analytes, especially, less than 1μg mL-1.
Silica-based monolithic column material was synthesized and an enrichment device was fabricated with the material by assembling the material inside a glass column. The enrichment device was applied for the determination of micro-carbaryl with near-infrared spectroscopy (NIRS). The aqueous solutions of carbaryl passed through the device and the carbaryl was enriched on the surface of the material where diffuse reflection NIR spectra were measured. These procedures of enrichment and measurement ensured to concentrate analytes for the measurement, so that the sensitivity of determination of NIRS could be improved. NIR spectra of carbaryl solutions (0.01-1.00μg mL-1), measured after the application of the enrichment device, were pretreated with multiplicative scatter correction (MSC) and regressed against the concentrations of the carbaryl solutions with partial least squares (PLS) method. The results showed that the minimum value of root-mean-square error of prediction (RMSEP) was 0.1771μg mL-1 when the number of latent variables was 3 of PLS regression. Therefore, the number of latent variables 3 was selected as the optimum value. RMSEP was not very low but acceptable considering that NIRS is commonly used in macro amount analysis and it is quite difficult for NIRS to determine micro amount analytes, especially, less than 1μg mL-1.
2009, 20(4): 473-477
doi: 10.1016/j.cclet.2008.12.014
Abstract:
A pH-responsive polymer Eudragit S-100 has been found to assist in correct folding of FGF-2(fibroblast growth factor-2) denatured with 8 mol/L urea and 10 mmol/L dithiothreitol at pH 7.2. The refolding of FGF-2 was performed by directly diluting denatured FGF-2 into a refolding buffer containing Eudragit S-100. The ability of Eudragit S-100 to enhance protein refolding level was investigated using MTT method, fluorescence emission spectroscopy and reverse phase HPLC. On the other hand, the result shows the ability of Eudragit S-100 to enhance the refolding level of protein is due to the interaction between Eudragit S-100 and positively charged FGF-2.
A pH-responsive polymer Eudragit S-100 has been found to assist in correct folding of FGF-2(fibroblast growth factor-2) denatured with 8 mol/L urea and 10 mmol/L dithiothreitol at pH 7.2. The refolding of FGF-2 was performed by directly diluting denatured FGF-2 into a refolding buffer containing Eudragit S-100. The ability of Eudragit S-100 to enhance protein refolding level was investigated using MTT method, fluorescence emission spectroscopy and reverse phase HPLC. On the other hand, the result shows the ability of Eudragit S-100 to enhance the refolding level of protein is due to the interaction between Eudragit S-100 and positively charged FGF-2.
2009, 20(4): 478-482
doi: 10.1016/j.cclet.2008.12.041
Abstract:
Miniemulsion copolymerization of butyl mathacrylate (BMA) with fluoroacrylate (HFMA, TFMA) was carried out at 70℃ by employing potassium persulphate (KPS) as initiator. Copolymer compositions at low conversion levels were determined by 1H NMR spectra techniques. The reactivity ratios were evaluated by employing Kellen-Tudos (K-T) methods, which yields the apparent reactivity ratios, rBMA=0.74, rHFMA=0.87 and rBMA=0.73, rTFMA=0.75, respectively, and Q-and e-values of HFMA and TFMAwere calculated by the Alfrey-Price method. The results show that HFMA and TFMA are more active than BMA, and the cross-propagation rate constant is greater than the self-propagation one in these two copolymerizations.
Miniemulsion copolymerization of butyl mathacrylate (BMA) with fluoroacrylate (HFMA, TFMA) was carried out at 70℃ by employing potassium persulphate (KPS) as initiator. Copolymer compositions at low conversion levels were determined by 1H NMR spectra techniques. The reactivity ratios were evaluated by employing Kellen-Tudos (K-T) methods, which yields the apparent reactivity ratios, rBMA=0.74, rHFMA=0.87 and rBMA=0.73, rTFMA=0.75, respectively, and Q-and e-values of HFMA and TFMAwere calculated by the Alfrey-Price method. The results show that HFMA and TFMA are more active than BMA, and the cross-propagation rate constant is greater than the self-propagation one in these two copolymerizations.
2009, 20(4): 483-486
doi: 10.1016/j.cclet.2008.12.034
Abstract:
Polypropylene synthetic paper releasing anion was prepared from polypropylene resin, anion additives, titanium dioxide, etc., by calendar forming method. The synthetic paper was tested by anion detector, SEM, AFM, etc. Tensile strength, elongation at break,right angle tear strength of the polypropylene synthetic paper reached the GB 13022 or QB/T1130 Standard. The synthetic paper was water and oil resistance, and released anions 10,530 cm-3. It was environment-friendly, and a kind of good material for human's health.
Polypropylene synthetic paper releasing anion was prepared from polypropylene resin, anion additives, titanium dioxide, etc., by calendar forming method. The synthetic paper was tested by anion detector, SEM, AFM, etc. Tensile strength, elongation at break,right angle tear strength of the polypropylene synthetic paper reached the GB 13022 or QB/T1130 Standard. The synthetic paper was water and oil resistance, and released anions 10,530 cm-3. It was environment-friendly, and a kind of good material for human's health.
2009, 20(4): 487-491
doi: 10.1016/j.cclet.2008.11.035
Abstract:
Poly(trimethylene terephthalate) (PTT) is an excellent fiber material. Its thermal degradation and isothermal crystalline behaviors were in this study investigated using thermogravimetric analysis (TGA), thermogravimetric analysis-Fourier transform infrared spectroscopy (TGA-FTIR) analysis, differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The thermal degradation mechanism of PTT follows Mclafferty rearrangement principle. The PTTwith intrinsic viscosity (IV) of 0.74 dl/g has a maximum crystallinity of about 55% at 190℃, as demonstrated by DSC and XRD measurements consistently.
Poly(trimethylene terephthalate) (PTT) is an excellent fiber material. Its thermal degradation and isothermal crystalline behaviors were in this study investigated using thermogravimetric analysis (TGA), thermogravimetric analysis-Fourier transform infrared spectroscopy (TGA-FTIR) analysis, differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The thermal degradation mechanism of PTT follows Mclafferty rearrangement principle. The PTTwith intrinsic viscosity (IV) of 0.74 dl/g has a maximum crystallinity of about 55% at 190℃, as demonstrated by DSC and XRD measurements consistently.
2009, 20(4): 492-495
doi: 10.1016/j.cclet.2008.11.019
Abstract:
A hydrophobic hypercrosslinked polymeric resin LC-1 was prepared and characterized. The properties of LC-1 resin were compared with those of a commercial hypercrosslinked polymer NDA-201 resin. In addition, the dynamic adsorption of trichloroethylene (TCE) onto LC-1 under dry and humid conditions at 303 K was investigated, the result shows that LC-1 possesses high hydrophobic property and can remove TCE from gas stream without effect of high humidity efficiently.
A hydrophobic hypercrosslinked polymeric resin LC-1 was prepared and characterized. The properties of LC-1 resin were compared with those of a commercial hypercrosslinked polymer NDA-201 resin. In addition, the dynamic adsorption of trichloroethylene (TCE) onto LC-1 under dry and humid conditions at 303 K was investigated, the result shows that LC-1 possesses high hydrophobic property and can remove TCE from gas stream without effect of high humidity efficiently.
2009, 20(4): 496-500
doi: 10.1016/j.cclet.2008.12.022
Abstract:
Three polychlorinated biphenyls (PCBs) congeners and their corresponding haptens bearing four carbon length carboxylic groups that can be linked to a protein for raising antibodies were synthesized. The three resultant immunogens were fabricated and used to stimulate immune responses in rabbits to survey the characteristics of the haptens. Three of the resultant polyclonal antibodies (Pabs) were obtained. The antiserum exhibited relatively high antibody titres (1:32-64) in double agar diffusion.
Three polychlorinated biphenyls (PCBs) congeners and their corresponding haptens bearing four carbon length carboxylic groups that can be linked to a protein for raising antibodies were synthesized. The three resultant immunogens were fabricated and used to stimulate immune responses in rabbits to survey the characteristics of the haptens. Three of the resultant polyclonal antibodies (Pabs) were obtained. The antiserum exhibited relatively high antibody titres (1:32-64) in double agar diffusion.
2009, 20(4): 501-505
doi: 10.1016/j.cclet.2008.12.020
Abstract:
In the present work, effect of the attraction terms of four recently modified Peng-Robinson equations of state on the prediction of solubility of caffeine, cholesterol, uracil and erythromycin was studied. The attraction terms of two of these equations are linear relative to the acentric factor and for the other two are exponential. It is found that the later show less deviation. Also interaction parameters for the studied systems are obtained and the percentage of average absolute relative deviation (%AARD) in each calculation is displayed.
In the present work, effect of the attraction terms of four recently modified Peng-Robinson equations of state on the prediction of solubility of caffeine, cholesterol, uracil and erythromycin was studied. The attraction terms of two of these equations are linear relative to the acentric factor and for the other two are exponential. It is found that the later show less deviation. Also interaction parameters for the studied systems are obtained and the percentage of average absolute relative deviation (%AARD) in each calculation is displayed.
