A series of low-temperature phase transitions of sodium aluminate solutions were studied by differential scanning calorimetry (DSC) and Raman spectroscopy. The results indicate that NaOH concentration is a primary imp...A series of low-temperature phase transitions of sodium aluminate solutions were studied by differential scanning calorimetry (DSC) and Raman spectroscopy. The results indicate that NaOH concentration is a primary impact factor for the binary eutectic point and ice melting temperature of sodium aluminate solutions with low NaOH concentration. In addition, the phase transition process of sodium aluminate solutions with low NaOH concentration from 123.15 to 283.15 K is divided into four steps: non-crystal to crystal, ternary eutectic reaction, binary eutectic reaction and ice melt. The projection phase diagram of NaOH-Al(OH)3-H2O system at low temperature was plotted, in which the ternary eutectic temperature for sodium aluminate solutions is 183.15 K.展开更多
A novel poly(ether ether ketone) derived from 2 (6 oxide 6H dibenz〈c, e〉〈1, 2〉oxa phospho rin 6 yl) 1,4 dihydroxyphenylene, 4, 4′ diflourodiphenylketone and bisphenol A was synthesized by solution polycondensatio...A novel poly(ether ether ketone) derived from 2 (6 oxide 6H dibenz〈c, e〉〈1, 2〉oxa phospho rin 6 yl) 1,4 dihydroxyphenylene, 4, 4′ diflourodiphenylketone and bisphenol A was synthesized by solution polycondensation. The influences of reaction time, and concentration of reactants on the polymerization were investigated . A copolymer with inherent viscosity of 1 44 was obtained. As characterized by FT IR, 1 H NMR and 31 P NMR the product was a terpolymer, consisted of bisphenol A and difluorodiphenylketone. The DSC analysis show its T g was 171 ℃. The copolymer was soluble in many polar solvents.展开更多
A monomer of tetrachloroterephthaloyl chloride (TCTPC) was prepared by the chlorination of terephthaloyl chloride catalyzed by ferric chloride at 175～180℃ for 10 h,and confirmed by FTIR,MS and elemental analysis.A s...A monomer of tetrachloroterephthaloyl chloride (TCTPC) was prepared by the chlorination of terephthaloyl chloride catalyzed by ferric chloride at 175～180℃ for 10 h,and confirmed by FTIR,MS and elemental analysis.A soluble polychloro substituted poly(aryletherketoneketone) (C-PEKK) was prepared by low temperature solution electrophilic Friedel-Crafts reaction of TCTPC and diphenyl ether (DPE) in 1,2-dichloroethane in the presence of AlCl 3 and N-methyl-2-pyrrolidinone(NMP).Effects of the molar ratio of monomers and the amounts of AlCl 3 and NMP on the polycondensation were investigated.Some propersites of the polymer was characterized by FT-IR,DSC,TGA and WAXD,etc.The results shown that the glass transition temperature(270℃) of the polymer is higher than that of pure PEEK and PEKK,and the polymer was noncrystalline.The polymer was soluble in common organic solvents such as DMF,DMSO,NMP,CHCl 3 and THF at room temperature and showed excellent thermal stability at temperature over 500℃ in air,high char yields of 61% in nitrogen and 54% in air at 700℃.展开更多
A novel unsymmetrical dianhydride containing 4\|(4\|hydroxylphenyl)\|2,3\|phthalazin\|1\|one was synthesized in order to improve the solubility of aromatic polyimides according to the principle of designing new monome...A novel unsymmetrical dianhydride containing 4\|(4\|hydroxylphenyl)\|2,3\|phthalazin\|1\|one was synthesized in order to improve the solubility of aromatic polyimides according to the principle of designing new monomers.This article reported a series of polyimide random copolymers derived from 4,4′ diamino diphenyl sulfone (DAPS),4,4′ oxyl dianiline (ODA) and the new dianhydride\|2 (3,4 dicarboxyl phenyl) 4 (3′,4′ dicarboxyl phenyl oxyl) phenyl 2,3 phthalazine 1 one dianhydride (DAH4) by“one step”solution polycondensation in m cresol with catalystic amount of isoquinoline at 200℃.Some properties of the copolymers were investigated by DSC,TG and mechanical analysis.The result shows that the η inh of copolymers is between 0 64 to 0 71 dL/g in m cresol at 25℃,and the T g of the copolymers are higher than that of pure poliymides containing 4,4′ oxyl dianiline (polymer 5).The relationship between T g and mole percent of DAPS is not obvious.Degradation temperature for 5% weight loss ( T d5 ) of the copolymers occurs all above 470℃ in air.The mechanical properties of the copolymers are lower owing to introducing sulfone groups into polymer’s backbone.In sharp contrast,the copolymers have good solubility and can be easily soluble in 1,1,2,2 tetrachloroethane(TCE), N,N dimethylacetamide(DMAc), N methyl 2 pyrrolidinone (NMP), m cresol and pyridine.Furthermore,the copolymers have better solubility in dimethyl sulfoxide (DMSO) and chloroform than the polyimide derived from DAH4 and ODA.展开更多
基金Project(51374251)supported by the National Natural Science Foundation of China
文摘A series of low-temperature phase transitions of sodium aluminate solutions were studied by differential scanning calorimetry (DSC) and Raman spectroscopy. The results indicate that NaOH concentration is a primary impact factor for the binary eutectic point and ice melting temperature of sodium aluminate solutions with low NaOH concentration. In addition, the phase transition process of sodium aluminate solutions with low NaOH concentration from 123.15 to 283.15 K is divided into four steps: non-crystal to crystal, ternary eutectic reaction, binary eutectic reaction and ice melt. The projection phase diagram of NaOH-Al(OH)3-H2O system at low temperature was plotted, in which the ternary eutectic temperature for sodium aluminate solutions is 183.15 K.
文摘A novel poly(ether ether ketone) derived from 2 (6 oxide 6H dibenz〈c, e〉〈1, 2〉oxa phospho rin 6 yl) 1,4 dihydroxyphenylene, 4, 4′ diflourodiphenylketone and bisphenol A was synthesized by solution polycondensation. The influences of reaction time, and concentration of reactants on the polymerization were investigated . A copolymer with inherent viscosity of 1 44 was obtained. As characterized by FT IR, 1 H NMR and 31 P NMR the product was a terpolymer, consisted of bisphenol A and difluorodiphenylketone. The DSC analysis show its T g was 171 ℃. The copolymer was soluble in many polar solvents.
文摘A monomer of tetrachloroterephthaloyl chloride (TCTPC) was prepared by the chlorination of terephthaloyl chloride catalyzed by ferric chloride at 175～180℃ for 10 h,and confirmed by FTIR,MS and elemental analysis.A soluble polychloro substituted poly(aryletherketoneketone) (C-PEKK) was prepared by low temperature solution electrophilic Friedel-Crafts reaction of TCTPC and diphenyl ether (DPE) in 1,2-dichloroethane in the presence of AlCl 3 and N-methyl-2-pyrrolidinone(NMP).Effects of the molar ratio of monomers and the amounts of AlCl 3 and NMP on the polycondensation were investigated.Some propersites of the polymer was characterized by FT-IR,DSC,TGA and WAXD,etc.The results shown that the glass transition temperature(270℃) of the polymer is higher than that of pure PEEK and PEKK,and the polymer was noncrystalline.The polymer was soluble in common organic solvents such as DMF,DMSO,NMP,CHCl 3 and THF at room temperature and showed excellent thermal stability at temperature over 500℃ in air,high char yields of 61% in nitrogen and 54% in air at 700℃.
文摘A novel unsymmetrical dianhydride containing 4\|(4\|hydroxylphenyl)\|2,3\|phthalazin\|1\|one was synthesized in order to improve the solubility of aromatic polyimides according to the principle of designing new monomers.This article reported a series of polyimide random copolymers derived from 4,4′ diamino diphenyl sulfone (DAPS),4,4′ oxyl dianiline (ODA) and the new dianhydride\|2 (3,4 dicarboxyl phenyl) 4 (3′,4′ dicarboxyl phenyl oxyl) phenyl 2,3 phthalazine 1 one dianhydride (DAH4) by“one step”solution polycondensation in m cresol with catalystic amount of isoquinoline at 200℃.Some properties of the copolymers were investigated by DSC,TG and mechanical analysis.The result shows that the η inh of copolymers is between 0 64 to 0 71 dL/g in m cresol at 25℃,and the T g of the copolymers are higher than that of pure poliymides containing 4,4′ oxyl dianiline (polymer 5).The relationship between T g and mole percent of DAPS is not obvious.Degradation temperature for 5% weight loss ( T d5 ) of the copolymers occurs all above 470℃ in air.The mechanical properties of the copolymers are lower owing to introducing sulfone groups into polymer’s backbone.In sharp contrast,the copolymers have good solubility and can be easily soluble in 1,1,2,2 tetrachloroethane(TCE), N,N dimethylacetamide(DMAc), N methyl 2 pyrrolidinone (NMP), m cresol and pyridine.Furthermore,the copolymers have better solubility in dimethyl sulfoxide (DMSO) and chloroform than the polyimide derived from DAH4 and ODA.
