Four series of copolyesters were synthesized by direct polycondonsation reaction between aromatic dicarboxylic acids and bisphenols by using tosyi chloride and N, N-dimethylformamide ( DMF ) in pyridine under mild con...Four series of copolyesters were synthesized by direct polycondonsation reaction between aromatic dicarboxylic acids and bisphenols by using tosyi chloride and N, N-dimethylformamide ( DMF ) in pyridine under mild conditions. The electron-rich hydroxyl groups of bisphenols favoured the polycondensation reaction and the order of relative reactivities of bisphenols is as follow:bisphenoI-A> hydroquinone ～ bisphenol-S> chlorohydroquinone. The mesomorphic properties of copolyesters were examined by birefringence under polarizing microscope, melt transparency. DSC and X-ray diffraction. The minimum molar fraction of mesogenic units needed for the appearance of liquid crystallinity is not higher than 0. 1 despite of the different varieties and lengths of the spacers studied.展开更多
1 Results Polylactide or polylactic acid (PLA) and poly(lactic-co-glycolic acid) (PLGA) have been utilized as bioabsorbable materials in the medical and pharmaceutical fields due to their biodegradable and biocompatib...1 Results Polylactide or polylactic acid (PLA) and poly(lactic-co-glycolic acid) (PLGA) have been utilized as bioabsorbable materials in the medical and pharmaceutical fields due to their biodegradable and biocompatible properties[1].However,due to its hydrophobicity and free carboxylic group,PLA or PLGA was not suitable for use to encapsulate the protein.Recently,poly (ε-caprolactone) and poly (D,L-lactide) were respectively grafted onto hydrophilic dextrin and gelatin to obtain the amphiphilic biodeg...展开更多
Four thiophene derivatives were prepared by replacing the 3,4 positions of thiophene by―OCH3, ―CH3―COOCH3 and ―CN, respectively. The polycondensations via direct arylation took place between the four thiophene der...Four thiophene derivatives were prepared by replacing the 3,4 positions of thiophene by―OCH3, ―CH3―COOCH3 and ―CN, respectively. The polycondensations via direct arylation took place between the four thiophene derivatives and 2,7-dibromo-9,9-dioctylfluorene under six various catalytic conditions to investigate the substituent effects. The substituent can affect the electron cloud density of the active C―H bond, which can be monitored by the NMR chemical shift. The experimental results show that the reactivity decreases with increasing the chemical shift of active C―H bonds in the four thiophene derivatives, and thus can promote the direct arylation polycondensation. This phenomenon is explained by the electrophilic aromatic substitution（SEAr） mechanism. UV-Visible absorption and photoluminescence were studied to investigate the substituent effect on optical properties of the four copolymers. The results show that these alternating fluorene-thiophene copolymers with different substituents are good fluorescent materials and promising in PLED applications.展开更多
The solubility of a direct arylation polycondensation(DArP)synthesized conjugated polymer,i.e.,poly(3,6-bis(furan-2-yl)-2,5-bis(4-tetradecyloctadecyl)-pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione-alt-1,2-bis(3,4-d ifl uorot...The solubility of a direct arylation polycondensation(DArP)synthesized conjugated polymer,i.e.,poly(3,6-bis(furan-2-yl)-2,5-bis(4-tetradecyloctadecyl)-pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione-alt-1,2-bis(3,4-d ifl uorothien-2-yl)ethene)(PFuD PP-4FTVT),in variou s organic solvents was studied.The polymer is soluble in 3-methylcyclohexanone(3-MC),a green solvent from peppermint oil,besides other solvents such as anisole,cyclopentyl methyl ether(CPME)and o-dichlorobenzene(o-DCB),etc.Based on the Hansen solu bility parameters(HSP)analysis,3-MC is identified as a"marginal solvent"of PFuDPP-4FTVT.The morphology of the spin-coated films with 3-MC as the solvent strongly correlated with the solution preparation conditions.With a 3-MC solution aged for 3 h at 70℃,n-channel organic thin-film transistors(OTFTs)with electron mobility(μe)above 1 cm^(2)·V^(-1)·s^(-1) and current on/off ratio(Ion/Ioff)higher than 105 were fabricated by spin-coating.This is the first report on high mobility conjugated polymers for OTFTs processible with natu rally occurred green solvent.展开更多
New types of polyamides containing pendent triaryl pyridine groups were successfully synthesized by direct polycondensation of a symmetry diamine,（4-（4-（2,6-diphenylpyridin-4yl）phenoxy）phenyl）-3,5-diaminobezamid...New types of polyamides containing pendent triaryl pyridine groups were successfully synthesized by direct polycondensation of a symmetry diamine,（4-（4-（2,6-diphenylpyridin-4yl）phenoxy）phenyl）-3,5-diaminobezamide（DPDAB）, and various aromatic and aliphatic dicarboxylic diacids in NMP using triphenyl phosphate（TPP） and pyridine as catalyst. The diamine and all the prepared polyamides were fully characterized by using FT-IR,~1H-NMR,UV-Vis spectroscopy, fluorimetry and elemental analysis.The inherent viscosity of polyamides ranged from 0.45 dL/g to 0.68 dL/g.All the polymers exhibited solubility in common polar aprotic solvents such as NMP,DMAc,DMF,DMSO,pyridine,HMPA,and even in less polar solvents such as THF and m-cresol at room temperature.Thermal properties of polyamides were evaluated by means of DSC,DMTA and TGA.These polymers showed glass transition temperatures（T_g） in the range of 138-210℃. Their initial decomposition temperature（T_i） varied from 265℃to 310℃under N_2.The dilute solution（0.2 g/dL） of polyamides in DMF exhibited fluorescence emission withλ_（max） in the range of 470-550 nm.展开更多
Six new optically active poly（amide-imide）s （5a-f） were synthesized through the direct polycondensation reaction of N,N′-（4,4′- diphthaloyl）-bis-L-leucine （3） with six hydantoin derivatives （4a-f）. Tripben...Six new optically active poly（amide-imide）s （5a-f） were synthesized through the direct polycondensation reaction of N,N′-（4,4′- diphthaloyl）-bis-L-leucine （3） with six hydantoin derivatives （4a-f）. Tripbenyl phosphite （TPP）/pyridine in the presence of calcium chloride （CaCl2） and N-methyl-2-pyrrolidone （NMP） were successfully applied for direct polycondensation. The polycondensation reactions produce a series of new poly（amide-imide）s （5a-f） in high yields, and inherent viscosity between 0.42 and 0,55 dL/g. The resulting poly（amide-imide）s （5a-f） were characterized by elemental analysis, viscosity measurements, thermal gravimetric analysis （TGA and DTG）, solubility test and FT-IR spectroscopy.展开更多
In this article,six new optically active copoly(amide-imide)s(10a-f) were synthesized through the direct polycondensation reaction of N-phthalimido-L-aspartic acid(4) with 1,5-diamino naphthalene(8),3,4-diamino benzop...In this article,six new optically active copoly(amide-imide)s(10a-f) were synthesized through the direct polycondensation reaction of N-phthalimido-L-aspartic acid(4) with 1,5-diamino naphthalene(8),3,4-diamino benzophenone(9) in the presence of therphthahc acid(7),fumaric acid(6) and adipic acid(5) as a second diacid in a medium consisting of N-methyl-2-pyrrolidone,triphenyl phosphite, calcium chloride and pyridine.The resulting copolymers were fully characterized by means of FT-IR spectroscopy,elemental a...展开更多
Soluble aromatic polyamides containing phthalazinone moieties were prepared. Those polymers were obtained from the solution polymerization of a new diacid containing phthalazinone moieties with various diamines. The ...Soluble aromatic polyamides containing phthalazinone moieties were prepared. Those polymers were obtained from the solution polymerization of a new diacid containing phthalazinone moieties with various diamines. The new monomer, 2-(4-carboxyphenyl)-4-(4- carboxyphenoxy ) phenyl-1 (2H) phthalazinone (Ⅳ) was synthesized in a two-step reaction sequence. 2- (4-Cyanophenyl)-4-(4-cyanophenoxy)phenyl-1 (2H)phthalazinone (Ⅲ) was prepared via the condensation reaction of 4-(4-hydroxyphenyl )-1 (2H) phthalazinone (I) with p-chlorobenzonitrile (Ⅱ). After (Ⅲ) was hydrolyzed, (Ⅳ) was acquired. The synthesized polyamides were characterized by means of viscosimetry, DSC, FT-IR, ~1H NMR and EA. The polyamides have a high glass transition temperature which can be as high as 316 C. The polyamides also have good solubilities in some organic solvents.展开更多
Direct arylation polycondensation(DArP)has emerged as an eco-friendly and atom-efficient methodology for the syntheses ofπ-conjugated polymers(CPs).This approach features the direct C—H arylation of an aromatic hydr...Direct arylation polycondensation(DArP)has emerged as an eco-friendly and atom-efficient methodology for the syntheses ofπ-conjugated polymers(CPs).This approach features the direct C—H arylation of an aromatic hydrocarbon with an aryl halide.Given the prevalence of thiophene-containing CPs,achieving efficient and defect-free DArP of thiophene-based C−H monomers is of great significance.This review presents a mechanistic insight into DArP and describes the development of DArP catalytic systems for varied thiophene-based C−H monomers.Moreover,the control of the primary defects(i.e.,branching and homo-coupling)in thiophene-based DArP is also elaborated.By emphasizing the principles behind monomer selection and catalytic system optimization,this review intends to provide a framework for future advancements in the DArP of thiophene-containing CPs.展开更多
Biodegradable aliphatic/aromatic copolyesters, poly（butylene terephthalate-co-lactate） （PBTL） were prepared via direct melt polycondensation of terephthalic acid （TPA）, 1,4-butanediol （BDO） and poly（L-lactic ...Biodegradable aliphatic/aromatic copolyesters, poly（butylene terephthalate-co-lactate） （PBTL） were prepared via direct melt polycondensation of terephthalic acid （TPA）, 1,4-butanediol （BDO） and poly（L-lactic acid） oligomer （OLLA）. The effects of polymerization time and temperature, as well as aliphatic/aromatic moiety ratio on the physical and thermal properties were investigated. The largest molecular weight of the copolyesters was up to 64100 with molecular weight distribution index of 2.09 when the polycondensation was carried out at 230℃ for 6 h. DSC, XRD, DMA and TGA analysis clearly indicated that the degree of crystallinity, glass-transition temperature, melting point, decomposition temperature, tensile strength, elongation and Young＇s modulus were influenced by the ratio between TPA and OLLA in the final copolyesters. Hydrolytic degradation results demonstrated that the incorporation of biodegradable lactate moieties into the aromatic polyester could efficiently improve hydrolytic degradability of the copolymer even though it still had many aromatic units in the main chains.展开更多
文摘Four series of copolyesters were synthesized by direct polycondonsation reaction between aromatic dicarboxylic acids and bisphenols by using tosyi chloride and N, N-dimethylformamide ( DMF ) in pyridine under mild conditions. The electron-rich hydroxyl groups of bisphenols favoured the polycondensation reaction and the order of relative reactivities of bisphenols is as follow:bisphenoI-A> hydroquinone ～ bisphenol-S> chlorohydroquinone. The mesomorphic properties of copolyesters were examined by birefringence under polarizing microscope, melt transparency. DSC and X-ray diffraction. The minimum molar fraction of mesogenic units needed for the appearance of liquid crystallinity is not higher than 0. 1 despite of the different varieties and lengths of the spacers studied.
文摘1 Results Polylactide or polylactic acid (PLA) and poly(lactic-co-glycolic acid) (PLGA) have been utilized as bioabsorbable materials in the medical and pharmaceutical fields due to their biodegradable and biocompatible properties[1].However,due to its hydrophobicity and free carboxylic group,PLA or PLGA was not suitable for use to encapsulate the protein.Recently,poly (ε-caprolactone) and poly (D,L-lactide) were respectively grafted onto hydrophilic dextrin and gelatin to obtain the amphiphilic biodeg...
基金financially supported by the National Natural Science Foundation of China(Nos.60976019 and 61250016)Education Department Program(No.JA12069)and Program for Innovative Research Team in Science and Technology in Fujian Province
文摘Four thiophene derivatives were prepared by replacing the 3,4 positions of thiophene by―OCH3, ―CH3―COOCH3 and ―CN, respectively. The polycondensations via direct arylation took place between the four thiophene derivatives and 2,7-dibromo-9,9-dioctylfluorene under six various catalytic conditions to investigate the substituent effects. The substituent can affect the electron cloud density of the active C―H bond, which can be monitored by the NMR chemical shift. The experimental results show that the reactivity decreases with increasing the chemical shift of active C―H bonds in the four thiophene derivatives, and thus can promote the direct arylation polycondensation. This phenomenon is explained by the electrophilic aromatic substitution（SEAr） mechanism. UV-Visible absorption and photoluminescence were studied to investigate the substituent effect on optical properties of the four copolymers. The results show that these alternating fluorene-thiophene copolymers with different substituents are good fluorescent materials and promising in PLED applications.
基金financially supported by the National Natural Science Foundation of China(Nos.51933008 and 52121002)the Fundamental Research Funds for the Central Universities。
文摘The solubility of a direct arylation polycondensation(DArP)synthesized conjugated polymer,i.e.,poly(3,6-bis(furan-2-yl)-2,5-bis(4-tetradecyloctadecyl)-pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione-alt-1,2-bis(3,4-d ifl uorothien-2-yl)ethene)(PFuD PP-4FTVT),in variou s organic solvents was studied.The polymer is soluble in 3-methylcyclohexanone(3-MC),a green solvent from peppermint oil,besides other solvents such as anisole,cyclopentyl methyl ether(CPME)and o-dichlorobenzene(o-DCB),etc.Based on the Hansen solu bility parameters(HSP)analysis,3-MC is identified as a"marginal solvent"of PFuDPP-4FTVT.The morphology of the spin-coated films with 3-MC as the solvent strongly correlated with the solution preparation conditions.With a 3-MC solution aged for 3 h at 70℃,n-channel organic thin-film transistors(OTFTs)with electron mobility(μe)above 1 cm^(2)·V^(-1)·s^(-1) and current on/off ratio(Ion/Ioff)higher than 105 were fabricated by spin-coating.This is the first report on high mobility conjugated polymers for OTFTs processible with natu rally occurred green solvent.
文摘New types of polyamides containing pendent triaryl pyridine groups were successfully synthesized by direct polycondensation of a symmetry diamine,（4-（4-（2,6-diphenylpyridin-4yl）phenoxy）phenyl）-3,5-diaminobezamide（DPDAB）, and various aromatic and aliphatic dicarboxylic diacids in NMP using triphenyl phosphate（TPP） and pyridine as catalyst. The diamine and all the prepared polyamides were fully characterized by using FT-IR,~1H-NMR,UV-Vis spectroscopy, fluorimetry and elemental analysis.The inherent viscosity of polyamides ranged from 0.45 dL/g to 0.68 dL/g.All the polymers exhibited solubility in common polar aprotic solvents such as NMP,DMAc,DMF,DMSO,pyridine,HMPA,and even in less polar solvents such as THF and m-cresol at room temperature.Thermal properties of polyamides were evaluated by means of DSC,DMTA and TGA.These polymers showed glass transition temperatures（T_g） in the range of 138-210℃. Their initial decomposition temperature（T_i） varied from 265℃to 310℃under N_2.The dilute solution（0.2 g/dL） of polyamides in DMF exhibited fluorescence emission withλ_（max） in the range of 470-550 nm.
文摘Six new optically active poly（amide-imide）s （5a-f） were synthesized through the direct polycondensation reaction of N,N′-（4,4′- diphthaloyl）-bis-L-leucine （3） with six hydantoin derivatives （4a-f）. Tripbenyl phosphite （TPP）/pyridine in the presence of calcium chloride （CaCl2） and N-methyl-2-pyrrolidone （NMP） were successfully applied for direct polycondensation. The polycondensation reactions produce a series of new poly（amide-imide）s （5a-f） in high yields, and inherent viscosity between 0.42 and 0,55 dL/g. The resulting poly（amide-imide）s （5a-f） were characterized by elemental analysis, viscosity measurements, thermal gravimetric analysis （TGA and DTG）, solubility test and FT-IR spectroscopy.
文摘In this article,six new optically active copoly(amide-imide)s(10a-f) were synthesized through the direct polycondensation reaction of N-phthalimido-L-aspartic acid(4) with 1,5-diamino naphthalene(8),3,4-diamino benzophenone(9) in the presence of therphthahc acid(7),fumaric acid(6) and adipic acid(5) as a second diacid in a medium consisting of N-methyl-2-pyrrolidone,triphenyl phosphite, calcium chloride and pyridine.The resulting copolymers were fully characterized by means of FT-IR spectroscopy,elemental a...
基金the National Natural Science Foundation of China
文摘Soluble aromatic polyamides containing phthalazinone moieties were prepared. Those polymers were obtained from the solution polymerization of a new diacid containing phthalazinone moieties with various diamines. The new monomer, 2-(4-carboxyphenyl)-4-(4- carboxyphenoxy ) phenyl-1 (2H) phthalazinone (Ⅳ) was synthesized in a two-step reaction sequence. 2- (4-Cyanophenyl)-4-(4-cyanophenoxy)phenyl-1 (2H)phthalazinone (Ⅲ) was prepared via the condensation reaction of 4-(4-hydroxyphenyl )-1 (2H) phthalazinone (I) with p-chlorobenzonitrile (Ⅱ). After (Ⅲ) was hydrolyzed, (Ⅳ) was acquired. The synthesized polyamides were characterized by means of viscosimetry, DSC, FT-IR, ~1H NMR and EA. The polyamides have a high glass transition temperature which can be as high as 316 C. The polyamides also have good solubilities in some organic solvents.
基金This work was financially supported by the National Key R&D Program of China(2021YFA0717900)National Natural Science Foundation of China(no.51933008,22222506 and 52121002).
文摘Direct arylation polycondensation(DArP)has emerged as an eco-friendly and atom-efficient methodology for the syntheses ofπ-conjugated polymers(CPs).This approach features the direct C—H arylation of an aromatic hydrocarbon with an aryl halide.Given the prevalence of thiophene-containing CPs,achieving efficient and defect-free DArP of thiophene-based C−H monomers is of great significance.This review presents a mechanistic insight into DArP and describes the development of DArP catalytic systems for varied thiophene-based C−H monomers.Moreover,the control of the primary defects(i.e.,branching and homo-coupling)in thiophene-based DArP is also elaborated.By emphasizing the principles behind monomer selection and catalytic system optimization,this review intends to provide a framework for future advancements in the DArP of thiophene-containing CPs.
基金supported by the Natural Science Foundation of Ningbo(No.2007A610030)Scientific Special Fund of Zhejiang Province(No.2008C11092-2)
文摘Biodegradable aliphatic/aromatic copolyesters, poly（butylene terephthalate-co-lactate） （PBTL） were prepared via direct melt polycondensation of terephthalic acid （TPA）, 1,4-butanediol （BDO） and poly（L-lactic acid） oligomer （OLLA）. The effects of polymerization time and temperature, as well as aliphatic/aromatic moiety ratio on the physical and thermal properties were investigated. The largest molecular weight of the copolyesters was up to 64100 with molecular weight distribution index of 2.09 when the polycondensation was carried out at 230℃ for 6 h. DSC, XRD, DMA and TGA analysis clearly indicated that the degree of crystallinity, glass-transition temperature, melting point, decomposition temperature, tensile strength, elongation and Young＇s modulus were influenced by the ratio between TPA and OLLA in the final copolyesters. Hydrolytic degradation results demonstrated that the incorporation of biodegradable lactate moieties into the aromatic polyester could efficiently improve hydrolytic degradability of the copolymer even though it still had many aromatic units in the main chains.
