Methyl methacrylate (MMA) emulsion polymerization in the presence of nanometer calcium carbonate(nano-CaCO3) surface modified with γ-methacryloxypropyltrimethoxysilane (MPTMS) was carried out to prepare poly (methyl ...Methyl methacrylate (MMA) emulsion polymerization in the presence of nanometer calcium carbonate(nano-CaCO3) surface modified with γ-methacryloxypropyltrimethoxysilane (MPTMS) was carried out to prepare poly (methyl methacrylate) (PMMA)/nano-CaCO3 composite. The reaction between nano-CaCO3 and MPTMS, and the grafting of PMMA onto nano-CaCO3 were confirmed by infrared spectrum. The grafting ratio and grafting efficiency of PMMA on nano-CaCO3 modified with MPTMS were much higher than that on nano-CaCO3 modified with stearic acid. The grafting ratio of PMMA increased as the weight ratio between MMA and nano-CaCO3 increased, while the grafting efficiency of PMMA decreased. Transmission electron micrograph showed that nano-CaCO3 covered with PMMA was formed by in-situ emulsion polymerization.展开更多
Acrylonitrile-methyl methacrylate （AN-MMA） copolymer/silica nanocomposites were synthesized by in-situ emulsion polymerization initiated by 2,2＇-azobis（2-amidinopropane） dihydrochloride absorbed onto colloidal si...Acrylonitrile-methyl methacrylate （AN-MMA） copolymer/silica nanocomposites were synthesized by in-situ emulsion polymerization initiated by 2,2＇-azobis（2-amidinopropane） dihydrochloride absorbed onto colloidal silica particles, and the mesoporous carbon materials were prepared through carbonization of the obtained AN-MMA copolymer/silica nanocomposites, followed by HF etching. Thermogravimetric analysis of AN-MMAcopolymer/silica nanocomposltes snoweO mat me caroon ylelCl or copolymer was slgnuy oecreaseo as Silica parucle incorporated. N2 adsorption-desorption, scan electron microscopy （SEM） and transmission electron microscopy （TEM） were used to characterize the structure and morphology of the mesoporous carbon materials. Both SEM and展开更多
Polyacrylonitriles （PANs） ware synthesized both by atom transfer radical polymerization （ATRP） anti free radical polymerization in ionic liquid 1 - buty - 3 - methylimidazolium chloride （[bmim]Cl）. [bmim]Cl demo...Polyacrylonitriles （PANs） ware synthesized both by atom transfer radical polymerization （ATRP） anti free radical polymerization in ionic liquid 1 - buty - 3 - methylimidazolium chloride （[bmim]Cl）. [bmim]Cl demonstrates to be a preferable solvent for ATRP of acrylonitrile （AN）. The polymerization maintains the usual advantages of ATRP with molecular weight agrees well with theoretical value and low polydispersity （PDI = 1.15）. It is also shown the higher conversion and lower molecular weight dispersion in ionic liquid than in dimethylformamide （DMF）. From FTIR and NMR analysis, it is confirmed that the chemical structures of PANs synthesized in [bmim]Cl were identical with that obtained in DMF. In atom transfer radical polymerization, the methine and cyan carbon atoms in isotactic configuration for PAN produced in [bmim] Cl have a configuration consisting of about 55.5% isotactic diads. It is higher than that obtained in DMF which is 52.2%. So, ionic liquid has effect on the stereostructure of PANs. Further analysis of ^13C NMR spectra indicated that the isotacticity of PAN synthesized by free radical polymerization was lower than that of PAN prepared by ATRP, although both of them were random in stereoregularity. Besides the pentad tacticities of PANs also suggested that the sequence distributions of them all obey Bernoulli statistics.展开更多
The liquid bulk technology can be divided into four parts： raw material refining, polymerization, flashed to live, granulation and packaging. There is an intrinsic link between them. This passage mainly makes some ex...The liquid bulk technology can be divided into four parts： raw material refining, polymerization, flashed to live, granulation and packaging. There is an intrinsic link between them. This passage mainly makes some experimental results to show that the process of raw material refining and polymerization.展开更多
The transmission of sexually transmitted infection （STI） pathogens from an infected donor to the recipient of a semen donation in assisted conception may result not only in acute infection but also in long-term repr...The transmission of sexually transmitted infection （STI） pathogens from an infected donor to the recipient of a semen donation in assisted conception may result not only in acute infection but also in long-term reproductive complications or adverse outcomes of pregnancy including infection of the offspring. Semen samples were obtained by masturbation into sterile containers. Samples were subjected to semen analysis within one hour of collection and processed for freezing within two hours of collection. The sperm motility was determined. After DNA extraction the PCR was performed and amplicons are subsequently hybridized to pathogen-specific capturing probes via ＂Flow-through＂ hybridization. During our study we came across with the STI pathogens present in semen and main cause of infertility was note. It was also observed that route for the transfer for these STI pathogens were the men working in other cities and visited commercial sex workers and their complained for infertility. We have reported our data that after the normal sperm count in semen samples of men with infertility or subfertility they were infected with Chlamtdia trachomatis, Neisseria gonorrhoeae, and Mycoplasma hominis. In our study all the 11 pathogens were detected which cause serious reproductive complications and infection in their offspring.展开更多
文摘Methyl methacrylate (MMA) emulsion polymerization in the presence of nanometer calcium carbonate(nano-CaCO3) surface modified with γ-methacryloxypropyltrimethoxysilane (MPTMS) was carried out to prepare poly (methyl methacrylate) (PMMA)/nano-CaCO3 composite. The reaction between nano-CaCO3 and MPTMS, and the grafting of PMMA onto nano-CaCO3 were confirmed by infrared spectrum. The grafting ratio and grafting efficiency of PMMA on nano-CaCO3 modified with MPTMS were much higher than that on nano-CaCO3 modified with stearic acid. The grafting ratio of PMMA increased as the weight ratio between MMA and nano-CaCO3 increased, while the grafting efficiency of PMMA decreased. Transmission electron micrograph showed that nano-CaCO3 covered with PMMA was formed by in-situ emulsion polymerization.
基金Supported by the Program for New Century Excellent Talents in University (NCET-07-0738)
文摘Acrylonitrile-methyl methacrylate （AN-MMA） copolymer/silica nanocomposites were synthesized by in-situ emulsion polymerization initiated by 2,2＇-azobis（2-amidinopropane） dihydrochloride absorbed onto colloidal silica particles, and the mesoporous carbon materials were prepared through carbonization of the obtained AN-MMA copolymer/silica nanocomposites, followed by HF etching. Thermogravimetric analysis of AN-MMAcopolymer/silica nanocomposltes snoweO mat me caroon ylelCl or copolymer was slgnuy oecreaseo as Silica parucle incorporated. N2 adsorption-desorption, scan electron microscopy （SEM） and transmission electron microscopy （TEM） were used to characterize the structure and morphology of the mesoporous carbon materials. Both SEM and
基金Science and Technology Commission of Shanghai Municipality fund (No.04JC14011)Shanghai Municipal Education Commission (No. DAWN Project) fund
文摘Polyacrylonitriles （PANs） ware synthesized both by atom transfer radical polymerization （ATRP） anti free radical polymerization in ionic liquid 1 - buty - 3 - methylimidazolium chloride （[bmim]Cl）. [bmim]Cl demonstrates to be a preferable solvent for ATRP of acrylonitrile （AN）. The polymerization maintains the usual advantages of ATRP with molecular weight agrees well with theoretical value and low polydispersity （PDI = 1.15）. It is also shown the higher conversion and lower molecular weight dispersion in ionic liquid than in dimethylformamide （DMF）. From FTIR and NMR analysis, it is confirmed that the chemical structures of PANs synthesized in [bmim]Cl were identical with that obtained in DMF. In atom transfer radical polymerization, the methine and cyan carbon atoms in isotactic configuration for PAN produced in [bmim] Cl have a configuration consisting of about 55.5% isotactic diads. It is higher than that obtained in DMF which is 52.2%. So, ionic liquid has effect on the stereostructure of PANs. Further analysis of ^13C NMR spectra indicated that the isotacticity of PAN synthesized by free radical polymerization was lower than that of PAN prepared by ATRP, although both of them were random in stereoregularity. Besides the pentad tacticities of PANs also suggested that the sequence distributions of them all obey Bernoulli statistics.
文摘The liquid bulk technology can be divided into four parts： raw material refining, polymerization, flashed to live, granulation and packaging. There is an intrinsic link between them. This passage mainly makes some experimental results to show that the process of raw material refining and polymerization.
文摘The transmission of sexually transmitted infection （STI） pathogens from an infected donor to the recipient of a semen donation in assisted conception may result not only in acute infection but also in long-term reproductive complications or adverse outcomes of pregnancy including infection of the offspring. Semen samples were obtained by masturbation into sterile containers. Samples were subjected to semen analysis within one hour of collection and processed for freezing within two hours of collection. The sperm motility was determined. After DNA extraction the PCR was performed and amplicons are subsequently hybridized to pathogen-specific capturing probes via ＂Flow-through＂ hybridization. During our study we came across with the STI pathogens present in semen and main cause of infertility was note. It was also observed that route for the transfer for these STI pathogens were the men working in other cities and visited commercial sex workers and their complained for infertility. We have reported our data that after the normal sperm count in semen samples of men with infertility or subfertility they were infected with Chlamtdia trachomatis, Neisseria gonorrhoeae, and Mycoplasma hominis. In our study all the 11 pathogens were detected which cause serious reproductive complications and infection in their offspring.
