Copolymer films of Acrylic acid/ Methyl methacrylate AAc/MMA with comonomer composition of 60/40 was prepared and then irradiated by gamma irradiation. The effect of irradiation on some of the physical properties of t...Copolymer films of Acrylic acid/ Methyl methacrylate AAc/MMA with comonomer composition of 60/40 was prepared and then irradiated by gamma irradiation. The effect of irradiation on some of the physical properties of the copolymer films was investigated. The dose level ranged from 5 to 200 kGy. The thermo gravimetric analysis (TGA) showed that the thermal stability of the films increased with irradiation dose up to 100 kGy then it started to decrease. The results of the UV-Visible spectroscopy of the films showed a decrease in the values of optical band gap and band tail width with doses starting from 100 kGy. The DC conductivity (?DC) of the films was found to decrease to about three orders of magnitude from its original value with irradiation dose up to 100 kGy then it started to increase with higher doses. Moreover, the dielectric constant and dielectric loss values were found to increase with dose up to 100 kGy which may be attributed to the increase in the number of dipoles in the films due to the irradiation of the copolymer films in air. The results indicated that crosslinking dominated over chain scission in the copolymer films with irradiation dose up to 100 kGy then at higher doses, chain scission dominated.展开更多
The methyl methacrylate(MMA)/1-propylmethacrylate-polyhedral oligomeric silsesquioxane(PM-POSS) copolymers were synthesized via atom transfer radical polymerization with CuBr as catalyst.The unreacted PM-POSS monomer ...The methyl methacrylate(MMA)/1-propylmethacrylate-polyhedral oligomeric silsesquioxane(PM-POSS) copolymers were synthesized via atom transfer radical polymerization with CuBr as catalyst.The unreacted PM-POSS monomer could be removed completely by washing the copolymerization product with n-hexane.The copolymers were characterized with ~1H-NMR,X-ray diffraction,differential scanning calorimetry,thermogravimetric analysis and gel permeation chromatography.With increasing PM-POSS feed ratio,the total conversi...展开更多
In this paper, methylmethacrylate-acrylic acid MMA-AA hydrophilic and hydrophobic copolymers were prepared by copolymerization for preparing membrane materials. The composite membrane of cellulose acetate (CA) blended...In this paper, methylmethacrylate-acrylic acid MMA-AA hydrophilic and hydrophobic copolymers were prepared by copolymerization for preparing membrane materials. The composite membrane of cellulose acetate (CA) blended with MMA-AA hydrophobic copolymer was used for the separation of methanol from pentane-methanol mixture. When the methanol concentration was only 1 wt%, the permeate flux still maintained at 350 g/m(2)h and separation factor was as big as 800. The composite membrane of PVA (polyvinyl alcohol) blended with MMA-AA hydrophilic copolymer was used for the separation of ethanol-water mixture. The permeate flux was increased to 975 g/m(2)h at 74 degrees C and the separation factor reached 3000 at 25 degrees C. The PVA/MMA-AA blended membrane surface modified by ammonia plasma was also investigated for separating ethanol-water mixture. Both permeate flux and separation factor of the membrane was improved. However, there was no obvious difference of plasma treatment time in the interval of 20 similar to 40 min.展开更多
The waterborne polyurethane-acrylate hybrid emulsions modified by methyl methacrylate(MMA)and butyl acrylate(BA)copolymer were synthesized by using 1,4-butanediol(BDO),dimethylopropionic(DMPA)and adipic dihyrazide(ADH...The waterborne polyurethane-acrylate hybrid emulsions modified by methyl methacrylate(MMA)and butyl acrylate(BA)copolymer were synthesized by using 1,4-butanediol(BDO),dimethylopropionic(DMPA)and adipic dihyrazide(ADH)as chain extenders.The effects of the amounts of BA and diacetone acrylamide(DAAM)on the properties of hybrid emulsions,films and adhesive were studied.The structure of the hybrid emulsions was characterized with Fourier transform infrared(FTIR).The experiment results showed that when the amount of BA was 4.0%—6.0%,that of DAAM was 2.0%—3.0%,the properties of the hybrid emulsion,films and adhesive were satisfactory.The adhesive which was made by polyurethane-acrylate hybrid emulsion with a better adhesive for wood.展开更多
Methyl methacrylate（MMA）—butyl acrylate（BA）—acrylic acid（AA） copolymer emulsion was prepared by emulsion polymerization using a redox initiation system of（NH4）2SO8-NaSO3.Factor of affecting copolymerization ...Methyl methacrylate（MMA）—butyl acrylate（BA）—acrylic acid（AA） copolymer emulsion was prepared by emulsion polymerization using a redox initiation system of（NH4）2SO8-NaSO3.Factor of affecting copolymerization and emulsion performance were studied.The experimental results show that the reaction rate,latex′s particle diameter and emulsion performance are affected by AA content.It is not important that the influence of composition of MMA-BA on the film forming.By seeding emulsion polymerization,copolymer emulsion stability is very well.Feeding ammonia water,the copolymer emulsion dissolved.Copolymer film is very good.展开更多
文摘Copolymer films of Acrylic acid/ Methyl methacrylate AAc/MMA with comonomer composition of 60/40 was prepared and then irradiated by gamma irradiation. The effect of irradiation on some of the physical properties of the copolymer films was investigated. The dose level ranged from 5 to 200 kGy. The thermo gravimetric analysis (TGA) showed that the thermal stability of the films increased with irradiation dose up to 100 kGy then it started to decrease. The results of the UV-Visible spectroscopy of the films showed a decrease in the values of optical band gap and band tail width with doses starting from 100 kGy. The DC conductivity (?DC) of the films was found to decrease to about three orders of magnitude from its original value with irradiation dose up to 100 kGy then it started to increase with higher doses. Moreover, the dielectric constant and dielectric loss values were found to increase with dose up to 100 kGy which may be attributed to the increase in the number of dipoles in the films due to the irradiation of the copolymer films in air. The results indicated that crosslinking dominated over chain scission in the copolymer films with irradiation dose up to 100 kGy then at higher doses, chain scission dominated.
基金the grant(R01-2004-000-10563-0)from the Basic Research Program of the Korea Science and Engineering Foundation.
文摘The methyl methacrylate(MMA)/1-propylmethacrylate-polyhedral oligomeric silsesquioxane(PM-POSS) copolymers were synthesized via atom transfer radical polymerization with CuBr as catalyst.The unreacted PM-POSS monomer could be removed completely by washing the copolymerization product with n-hexane.The copolymers were characterized with ~1H-NMR,X-ray diffraction,differential scanning calorimetry,thermogravimetric analysis and gel permeation chromatography.With increasing PM-POSS feed ratio,the total conversi...
基金The key project is supported by the National Natural Science Foundation of China(No.29836160).
文摘In this paper, methylmethacrylate-acrylic acid MMA-AA hydrophilic and hydrophobic copolymers were prepared by copolymerization for preparing membrane materials. The composite membrane of cellulose acetate (CA) blended with MMA-AA hydrophobic copolymer was used for the separation of methanol from pentane-methanol mixture. When the methanol concentration was only 1 wt%, the permeate flux still maintained at 350 g/m(2)h and separation factor was as big as 800. The composite membrane of PVA (polyvinyl alcohol) blended with MMA-AA hydrophilic copolymer was used for the separation of ethanol-water mixture. The permeate flux was increased to 975 g/m(2)h at 74 degrees C and the separation factor reached 3000 at 25 degrees C. The PVA/MMA-AA blended membrane surface modified by ammonia plasma was also investigated for separating ethanol-water mixture. Both permeate flux and separation factor of the membrane was improved. However, there was no obvious difference of plasma treatment time in the interval of 20 similar to 40 min.
文摘The waterborne polyurethane-acrylate hybrid emulsions modified by methyl methacrylate(MMA)and butyl acrylate(BA)copolymer were synthesized by using 1,4-butanediol(BDO),dimethylopropionic(DMPA)and adipic dihyrazide(ADH)as chain extenders.The effects of the amounts of BA and diacetone acrylamide(DAAM)on the properties of hybrid emulsions,films and adhesive were studied.The structure of the hybrid emulsions was characterized with Fourier transform infrared(FTIR).The experiment results showed that when the amount of BA was 4.0%—6.0%,that of DAAM was 2.0%—3.0%,the properties of the hybrid emulsion,films and adhesive were satisfactory.The adhesive which was made by polyurethane-acrylate hybrid emulsion with a better adhesive for wood.
文摘Methyl methacrylate（MMA）—butyl acrylate（BA）—acrylic acid（AA） copolymer emulsion was prepared by emulsion polymerization using a redox initiation system of（NH4）2SO8-NaSO3.Factor of affecting copolymerization and emulsion performance were studied.The experimental results show that the reaction rate,latex′s particle diameter and emulsion performance are affected by AA content.It is not important that the influence of composition of MMA-BA on the film forming.By seeding emulsion polymerization,copolymer emulsion stability is very well.Feeding ammonia water,the copolymer emulsion dissolved.Copolymer film is very good.
