Poly（phenylene sulfide/ether） （PPSE） was synthesized from 4,4＇-dihydroxydiphenyl sulfide and 4,4＇-dichlorodiphenyl sulfide in solution by nucleophilic substitution reaction. The resulting polymer was characteriz...Poly（phenylene sulfide/ether） （PPSE） was synthesized from 4,4＇-dihydroxydiphenyl sulfide and 4,4＇-dichlorodiphenyl sulfide in solution by nucleophilic substitution reaction. The resulting polymer was characterized by viscosity measurement, elemental analysis, FT-IR, ^1H NMR, X-ray diffraction and thermal analysis. The results showed that the viscosities of the resulting polymer were above 0.68 dL/g, and the linear chain structure of product was confirmed. PPSE had the same reflex indices as poly（p-phenylene sulfide）, an orthorhombic crystalline with unit cell a=0.853, b=0.562, c=1.026nm. The melting temperature, glass transition temperature and initial decomposition temperature were found to be 228℃, 85℃ and 325℃, respectively. The product was soluble in common organic solvents such as NMP, N, N＇-dimethylformamide, N, N＇-dimethylacetamide and 1,2-dichloroethane.展开更多
The thermal stability of oil gels formed by styrene-butadiene-styrene triblock copolymer (SBS) was improved by adding a small amount of poly(phenylene ether) (PPE), which has a higher glass transition temperature (Tg)...The thermal stability of oil gels formed by styrene-butadiene-styrene triblock copolymer (SBS) was improved by adding a small amount of poly(phenylene ether) (PPE), which has a higher glass transition temperature (Tg). In naphthenic oil which is a good solvent for the butadiene blocks, but a non-solvent for the styrene blocks and PPE, PPE was selectively included into styrene blocks in SBS, and induced the increase of the Tg of these blocks. The melting temperature determined by viscoelastic measurements and softening temperature of the gels were elevated by adding PPE, while no significant change was detected by adding polystyrene. The gel became opaque by adding PPE, and partially separated phases were observed by field emission scanning electron microscopy (FE-SEM). The dependence of the viscoelastic behavior on the PPE concentration can be explained by the structural change observed by FE-SEM.展开更多
A new biphenol-like monomer,4,4′-methylenebis[4-(1,4-phenylene)-phthalazin-1(2H)-one] was synthesized from phthalic anhydride and diphenylmethane in two steps.In the first step,Friedel-Crafts reaction was carried out...A new biphenol-like monomer,4,4′-methylenebis[4-(1,4-phenylene)-phthalazin-1(2H)-one] was synthesized from phthalic anhydride and diphenylmethane in two steps.In the first step,Friedel-Crafts reaction was carried out in 1,2-dichloroethane between diphenylmethane and phthalic anhydride.The obtained product was used in the second step with hydrazine monohydrate added into its solution,followed by recrystallization in acetic acid.The melting point showed by differential scanning calorimetry of the bis(phthalazinone) monomer was 338.1℃.The overall yield of the biphenol-like monomer was 60%.A new polyphthalazinone was prepared from 4,4′-difluorodiphenylketone(DFK) and 4,4′-methylenebis[4-(1,4-phenylene)-phthalazin-1(2H)-one] by solution polycondensation in N-methyl-2-pyrrolidone(NMP) with anhydrous K 2CO 3 as a catalyst.High molecular weight polymer was formed in 8 h at 190℃.The polymer was refined by precipitation from its 15% NMP solution with methanol as the precipitating agent.The powder of the polymer was dried in a vacuum oven under 120℃ for 48*!h and then under 200℃ for 4*!h.The intrinsic viscosity of the polymer was 0.58*!dL/g in NMP at 25℃.The polymer showed high glass transition temperature (T g) at 258℃ by DSC.The decomposition temperature for 5% weight loss (T d5) in nitrogen measured by thermogravimetric analysis occurred at 431℃.The solubility of the polymer was investigated at room temperature.The polymer was soluble in NMP,m-cresol and partially soluble in chloroform,and insoluble in N,N-dimethylacetamide (DMAc) and dimethyl sulfoxide (DMSO).The methylene group and bis-(phthalazinone) structure in the backbone of the polymer contribute much to the good solubility,and the rigid structure of bis(phthalazinone) retains its good thermal properties.展开更多
文摘Poly（phenylene sulfide/ether） （PPSE） was synthesized from 4,4＇-dihydroxydiphenyl sulfide and 4,4＇-dichlorodiphenyl sulfide in solution by nucleophilic substitution reaction. The resulting polymer was characterized by viscosity measurement, elemental analysis, FT-IR, ^1H NMR, X-ray diffraction and thermal analysis. The results showed that the viscosities of the resulting polymer were above 0.68 dL/g, and the linear chain structure of product was confirmed. PPSE had the same reflex indices as poly（p-phenylene sulfide）, an orthorhombic crystalline with unit cell a=0.853, b=0.562, c=1.026nm. The melting temperature, glass transition temperature and initial decomposition temperature were found to be 228℃, 85℃ and 325℃, respectively. The product was soluble in common organic solvents such as NMP, N, N＇-dimethylformamide, N, N＇-dimethylacetamide and 1,2-dichloroethane.
文摘The thermal stability of oil gels formed by styrene-butadiene-styrene triblock copolymer (SBS) was improved by adding a small amount of poly(phenylene ether) (PPE), which has a higher glass transition temperature (Tg). In naphthenic oil which is a good solvent for the butadiene blocks, but a non-solvent for the styrene blocks and PPE, PPE was selectively included into styrene blocks in SBS, and induced the increase of the Tg of these blocks. The melting temperature determined by viscoelastic measurements and softening temperature of the gels were elevated by adding PPE, while no significant change was detected by adding polystyrene. The gel became opaque by adding PPE, and partially separated phases were observed by field emission scanning electron microscopy (FE-SEM). The dependence of the viscoelastic behavior on the PPE concentration can be explained by the structural change observed by FE-SEM.
文摘A new biphenol-like monomer,4,4′-methylenebis[4-(1,4-phenylene)-phthalazin-1(2H)-one] was synthesized from phthalic anhydride and diphenylmethane in two steps.In the first step,Friedel-Crafts reaction was carried out in 1,2-dichloroethane between diphenylmethane and phthalic anhydride.The obtained product was used in the second step with hydrazine monohydrate added into its solution,followed by recrystallization in acetic acid.The melting point showed by differential scanning calorimetry of the bis(phthalazinone) monomer was 338.1℃.The overall yield of the biphenol-like monomer was 60%.A new polyphthalazinone was prepared from 4,4′-difluorodiphenylketone(DFK) and 4,4′-methylenebis[4-(1,4-phenylene)-phthalazin-1(2H)-one] by solution polycondensation in N-methyl-2-pyrrolidone(NMP) with anhydrous K 2CO 3 as a catalyst.High molecular weight polymer was formed in 8 h at 190℃.The polymer was refined by precipitation from its 15% NMP solution with methanol as the precipitating agent.The powder of the polymer was dried in a vacuum oven under 120℃ for 48*!h and then under 200℃ for 4*!h.The intrinsic viscosity of the polymer was 0.58*!dL/g in NMP at 25℃.The polymer showed high glass transition temperature (T g) at 258℃ by DSC.The decomposition temperature for 5% weight loss (T d5) in nitrogen measured by thermogravimetric analysis occurred at 431℃.The solubility of the polymer was investigated at room temperature.The polymer was soluble in NMP,m-cresol and partially soluble in chloroform,and insoluble in N,N-dimethylacetamide (DMAc) and dimethyl sulfoxide (DMSO).The methylene group and bis-(phthalazinone) structure in the backbone of the polymer contribute much to the good solubility,and the rigid structure of bis(phthalazinone) retains its good thermal properties.
