A bipolymer maleic anhydride-methyl acrylate （MAMA） was synthesized from maleic anhydride and methyl acrylate based on molecular design.MAMA further reacted with oleylamine or octadecyl alcohol to generate two comb ...A bipolymer maleic anhydride-methyl acrylate （MAMA） was synthesized from maleic anhydride and methyl acrylate based on molecular design.MAMA further reacted with oleylamine or octadecyl alcohol to generate two comb polymers called Oleamide-MAMA （NMAMA） and OctadecanolMAMA （OMAMA）,respectively.The structure of both the polymers was confirmed by their infrared spectral analysis （IR）,gel permeation chromatography analysis （GPC） and differential scanning calorimeter （DSC）.Moreover,the pour point depressing （PPD） properties of these comb polymers were examined experimentally.Experimental results showed that besides the molecular weight and concentration of the polymers,the length of side chains and the number of functional groups also had great influence on the pour point depressing performance.The π bonds and hydrogen bonds between depressants were the key factors for improving the pour point depressing properties.These results suggest that both OMAMA and NMAMA are potential pour point depressants for industry.展开更多
A series of polycarboxylate-based superplasticizers(PCs) with different structures were synthesized and the effects of chemical structure on zeta potential and rheological property of cement paste were studied. Residu...A series of polycarboxylate-based superplasticizers(PCs) with different structures were synthesized and the effects of chemical structure on zeta potential and rheological property of cement paste were studied. Residual monomers in each sample of PCs were quantitatively determined. The property of the polymers in cement was tested by micro-electrophoresis apparatus and R/S rheometer. Results showed that the zeta potential and its rheological properties are related with the side-chain length and density of PCs. The PCs having shorter side chain and lower side chain density exhibit higher anionic charge density, thus resulting in higher zeta potential. The effect of side chain density on zeta potential is more notable compared with that of side-chain length, and thus affecting the initial shear yield stress and apparent viscosity of the cement paste. In addition, although increasing the side chain length will result in reduction of the anionic charge density, the steric hindrance effect is obvious, which can effectively improve the dispersion of the cement particles, and reduce the viscosity and shear yield stress of slurry.展开更多
A comb polymer with oligo-oxyethylene side chains of the type -(CH2CB2O)(12)CH3 was prepared from methyl vinyl ether/maleic anhydride copolymer and poly (ethylene glycol) methyl ether. The polymer can dissolve LiClO4 ...A comb polymer with oligo-oxyethylene side chains of the type -(CH2CB2O)(12)CH3 was prepared from methyl vinyl ether/maleic anhydride copolymer and poly (ethylene glycol) methyl ether. The polymer can dissolve LiClO4 salt to form homogeneous amorphous polymer electrolyte. The ac ion conduction was measured using the complex impedance method, and conductivities were investigated as functions of temperatures and salt concentration. The complexes were first found to have two classes of glass transition which increase with increasing salt content, The optimum conductivity attained at 25 degrees C is in the order of 5.50 x 10(-6)Scm(-1). IR spectroscopy was used to study the cation-polymer interaction.展开更多
文摘A bipolymer maleic anhydride-methyl acrylate （MAMA） was synthesized from maleic anhydride and methyl acrylate based on molecular design.MAMA further reacted with oleylamine or octadecyl alcohol to generate two comb polymers called Oleamide-MAMA （NMAMA） and OctadecanolMAMA （OMAMA）,respectively.The structure of both the polymers was confirmed by their infrared spectral analysis （IR）,gel permeation chromatography analysis （GPC） and differential scanning calorimeter （DSC）.Moreover,the pour point depressing （PPD） properties of these comb polymers were examined experimentally.Experimental results showed that besides the molecular weight and concentration of the polymers,the length of side chains and the number of functional groups also had great influence on the pour point depressing performance.The π bonds and hydrogen bonds between depressants were the key factors for improving the pour point depressing properties.These results suggest that both OMAMA and NMAMA are potential pour point depressants for industry.
基金Funded by the Western Region Traffic Construction Technology Program of the Ministry of Communications of China(No.2007319811130)
文摘A series of polycarboxylate-based superplasticizers(PCs) with different structures were synthesized and the effects of chemical structure on zeta potential and rheological property of cement paste were studied. Residual monomers in each sample of PCs were quantitatively determined. The property of the polymers in cement was tested by micro-electrophoresis apparatus and R/S rheometer. Results showed that the zeta potential and its rheological properties are related with the side-chain length and density of PCs. The PCs having shorter side chain and lower side chain density exhibit higher anionic charge density, thus resulting in higher zeta potential. The effect of side chain density on zeta potential is more notable compared with that of side-chain length, and thus affecting the initial shear yield stress and apparent viscosity of the cement paste. In addition, although increasing the side chain length will result in reduction of the anionic charge density, the steric hindrance effect is obvious, which can effectively improve the dispersion of the cement particles, and reduce the viscosity and shear yield stress of slurry.
文摘A comb polymer with oligo-oxyethylene side chains of the type -(CH2CB2O)(12)CH3 was prepared from methyl vinyl ether/maleic anhydride copolymer and poly (ethylene glycol) methyl ether. The polymer can dissolve LiClO4 salt to form homogeneous amorphous polymer electrolyte. The ac ion conduction was measured using the complex impedance method, and conductivities were investigated as functions of temperatures and salt concentration. The complexes were first found to have two classes of glass transition which increase with increasing salt content, The optimum conductivity attained at 25 degrees C is in the order of 5.50 x 10(-6)Scm(-1). IR spectroscopy was used to study the cation-polymer interaction.
