Electrorheological properties and creep-recovery behavior of polythiophene/polyoxymethylene-blend having PT（50%）/POM（50%） composition were investigated.Particle size,conductivity and dielectric values were measure...Electrorheological properties and creep-recovery behavior of polythiophene/polyoxymethylene-blend having PT（50%）/POM（50%） composition were investigated.Particle size,conductivity and dielectric values were measured to be 24.77μm,3.85×10^（-5） S·m^（-1） and 26.75,respectively.Sedimentation ratio was measured to be 64%at the end of 16 days.The effects of dispersed particle volume fraction,external electric field strength,shear rate,frequency and temperature on ER properties and storage modulus of PT/POM-blend/silicone oil（SO） suspensions were examined.Enhancement were observed in the electric field viscosities of the suspensions and thus they were classified as a smart material.Shear thinning non-Newtonian viscoelastic behavior was determined for PT/POM-blend/SO system.Further,time-dependent deformation was examined by creep-recovery tests and recoverable viscoelastic deformation established.展开更多
The copolymerization of dibenzofuran(DBF)and 3-methylthiophene(MET)was successfully achieved electrochemically by direct anodic oxidation of the monomer mixtures in boron trifluoride diethyl etherate.The effects of ap...The copolymerization of dibenzofuran(DBF)and 3-methylthiophene(MET)was successfully achieved electrochemically by direct anodic oxidation of the monomer mixtures in boron trifluoride diethyl etherate.The effects of applied polymerization potential and the monomer concentration ratios on the copolymerization were investigated by linear sweep voltammetry and cyclic voltammetry(CV).The structure of copolymer films were investigated by UV-Vis,infrared spectroscopy,thermal analysis.As-formed novel copolymers own...展开更多
A series of polyvinylpyrrolidone-stabilized heteropolyacids(PVP-HPAs)are generated by self-assembly of HPAs and PVP in methanol.The PVP-HPAs are then employed as catalysts for the synthesis of poly(oxymethylene)dimeth...A series of polyvinylpyrrolidone-stabilized heteropolyacids(PVP-HPAs)are generated by self-assembly of HPAs and PVP in methanol.The PVP-HPAs are then employed as catalysts for the synthesis of poly(oxymethylene)dimethyl ethers(DMMn,n1)by the methanolysis of trioxane.The results suggest that the acidity of PVP-HPAs is tunable by changing the ratio of PVP and HPAs,which is a key factor for the selectivity of the DMMn product.By optimizing the composition and reaction conditions,two types of PVP-HPA,PVP-phosphotungstic acid(PVP-HPW)in a PVP/HPW ratio of 1/4:1 and PVP-silicotungstic acid(PVP-HSi W)in a PVP/HSi W ratio of 1/4:3/4,respectively afford 52.4%and 50.3%yields of DMM2–5.The optimized catalysts are reusable for a minimum of 10 times without a significant drop in performance.展开更多
The morphologies of poly(L-lactic acid)(PLLA)spherulites,when crystallized within the pre-existed poly(oxymethylene)(POM)crystal frameworks,have been investigated.PLLA/POM blend is a melt-miscible crystalline/crystall...The morphologies of poly(L-lactic acid)(PLLA)spherulites,when crystallized within the pre-existed poly(oxymethylene)(POM)crystal frameworks,have been investigated.PLLA/POM blend is a melt-miscible crystalline/crystalline blend system.Owing to the lower melting point but much faster crystallization rate than PLEA,POM crystallized first upon cooling from the melt state and then melted first during the subsequent heating process in this blend system.Lamellar assembly of PLLA crystals within the pre-existed POM spherulitic frameworks was directly observed with the polarized light microscopy by selectively melting the POM frameworks.The investigation indicated that PLLA crystals fully replicated the spherulitic morphology and optical birefringence of the POM crystal frameworks,which was independent of T_(o).On the other hand,POM could also duplicate the pre-existed PLLA morphologies.The result obtained provides us a possibility to design the lamellar assembly and crystal structures of polymer crystals in miscible crystalline/crystalline polymer blends.展开更多
At present,most of state-of-the-art power conversion efficiencies(PCEs)of organic solar cells(OSCs)are achieved from the photoactive materials involving donor–acceptor(D–A)copolymer donors.It is well known that the ...At present,most of state-of-the-art power conversion efficiencies(PCEs)of organic solar cells(OSCs)are achieved from the photoactive materials involving donor–acceptor(D–A)copolymer donors.It is well known that the complicated molecular structure of D–A copolymers means the tedious synthesis,which brings about severe cost issue and poor scalability for the industrial production.Therefore,to develop application-oriented OSCs,considerable attention should be paid on simplifying the chemical structures of polymer donors.Polythiophene(PT)and poly(thiophene vinylene)(PTV)derivatives should be among the simplest polymer donors,and OSCs based on them have made some breakthroughs in past 2 years.Here,we briefly introduce the recent advances of OSCs based on low-cost polymers including poly(3-hexylthiophene)(P3HT),PT derivatives,and PTV derivatives,respectively,and emphasize the importance of modulating energy levels,preaggregation effect,and D/A miscibility for the past progress as well as the future development.At last,we also propose some challenges demanding prompt solution for realizing practical application of OSCs,aiming at providing guidance and stimulating new ideas for further research.展开更多
用辐照的方法将反应性聚合物接枝到纳米 Ca CO3表面 ,研究接枝 Ca CO3对聚甲醛形态的影响 ,同时还就聚醚型聚氨酯 (TPU)及相容剂对聚甲醛复合材料的分散形态影响进行了讨论。研究结果表明 ,聚丙烯腈接技的 Ca CO3改善了与聚甲醛的界面...用辐照的方法将反应性聚合物接枝到纳米 Ca CO3表面 ,研究接枝 Ca CO3对聚甲醛形态的影响 ,同时还就聚醚型聚氨酯 (TPU)及相容剂对聚甲醛复合材料的分散形态影响进行了讨论。研究结果表明 ,聚丙烯腈接技的 Ca CO3改善了与聚甲醛的界面粘结状态 ,TPU的加入增强了 Ca展开更多
基金financially supported by Turkish Scientific and Technological Research Council(No.107 T 711)
文摘Electrorheological properties and creep-recovery behavior of polythiophene/polyoxymethylene-blend having PT（50%）/POM（50%） composition were investigated.Particle size,conductivity and dielectric values were measured to be 24.77μm,3.85×10^（-5） S·m^（-1） and 26.75,respectively.Sedimentation ratio was measured to be 64%at the end of 16 days.The effects of dispersed particle volume fraction,external electric field strength,shear rate,frequency and temperature on ER properties and storage modulus of PT/POM-blend/silicone oil（SO） suspensions were examined.Enhancement were observed in the electric field viscosities of the suspensions and thus they were classified as a smart material.Shear thinning non-Newtonian viscoelastic behavior was determined for PT/POM-blend/SO system.Further,time-dependent deformation was examined by creep-recovery tests and recoverable viscoelastic deformation established.
基金This work was financially supported by the Natural Science Foundation of China(Nos.50663001,20564001)Ministry of Education(No.2007-207058).
文摘The copolymerization of dibenzofuran(DBF)and 3-methylthiophene(MET)was successfully achieved electrochemically by direct anodic oxidation of the monomer mixtures in boron trifluoride diethyl etherate.The effects of applied polymerization potential and the monomer concentration ratios on the copolymerization were investigated by linear sweep voltammetry and cyclic voltammetry(CV).The structure of copolymer films were investigated by UV-Vis,infrared spectroscopy,thermal analysis.As-formed novel copolymers own...
基金financially supported by the National Basic Research Program of China(2011CBA00508)the National Natural Science Foundation of China(21173175,21303141)+1 种基金the Research Fund for the Doctoral Program of Higher Education(20110121130002)the Program for Changjiang Scholars and Innovative Research Team in University(IRT1036)
文摘A series of polyvinylpyrrolidone-stabilized heteropolyacids(PVP-HPAs)are generated by self-assembly of HPAs and PVP in methanol.The PVP-HPAs are then employed as catalysts for the synthesis of poly(oxymethylene)dimethyl ethers(DMMn,n1)by the methanolysis of trioxane.The results suggest that the acidity of PVP-HPAs is tunable by changing the ratio of PVP and HPAs,which is a key factor for the selectivity of the DMMn product.By optimizing the composition and reaction conditions,two types of PVP-HPA,PVP-phosphotungstic acid(PVP-HPW)in a PVP/HPW ratio of 1/4:1 and PVP-silicotungstic acid(PVP-HSi W)in a PVP/HSi W ratio of 1/4:3/4,respectively afford 52.4%and 50.3%yields of DMM2–5.The optimized catalysts are reusable for a minimum of 10 times without a significant drop in performance.
基金financially supported by the National Natural Science Foundation of China(Nos.21674033,21374027)National Key R&D Program of China(No.2017YFB0307704)
文摘The morphologies of poly(L-lactic acid)(PLLA)spherulites,when crystallized within the pre-existed poly(oxymethylene)(POM)crystal frameworks,have been investigated.PLLA/POM blend is a melt-miscible crystalline/crystalline blend system.Owing to the lower melting point but much faster crystallization rate than PLEA,POM crystallized first upon cooling from the melt state and then melted first during the subsequent heating process in this blend system.Lamellar assembly of PLLA crystals within the pre-existed POM spherulitic frameworks was directly observed with the polarized light microscopy by selectively melting the POM frameworks.The investigation indicated that PLLA crystals fully replicated the spherulitic morphology and optical birefringence of the POM crystal frameworks,which was independent of T_(o).On the other hand,POM could also duplicate the pre-existed PLLA morphologies.The result obtained provides us a possibility to design the lamellar assembly and crystal structures of polymer crystals in miscible crystalline/crystalline polymer blends.
基金National Key Research and Development Program of China,Grant/Award Number:2019YFE0116700Basic and Applied Basic Research Major Program of Guangdong Province,Grant/Award Number:2019B030302007National Natural Science Foundation of China,Grant/Award Numbers:21835006,91633301,22075017。
文摘At present,most of state-of-the-art power conversion efficiencies(PCEs)of organic solar cells(OSCs)are achieved from the photoactive materials involving donor–acceptor(D–A)copolymer donors.It is well known that the complicated molecular structure of D–A copolymers means the tedious synthesis,which brings about severe cost issue and poor scalability for the industrial production.Therefore,to develop application-oriented OSCs,considerable attention should be paid on simplifying the chemical structures of polymer donors.Polythiophene(PT)and poly(thiophene vinylene)(PTV)derivatives should be among the simplest polymer donors,and OSCs based on them have made some breakthroughs in past 2 years.Here,we briefly introduce the recent advances of OSCs based on low-cost polymers including poly(3-hexylthiophene)(P3HT),PT derivatives,and PTV derivatives,respectively,and emphasize the importance of modulating energy levels,preaggregation effect,and D/A miscibility for the past progress as well as the future development.At last,we also propose some challenges demanding prompt solution for realizing practical application of OSCs,aiming at providing guidance and stimulating new ideas for further research.
