The gradient copolymers of acrylic acid and trifluoroethyl methacrylate（coded as P（TFEMAgrad-AA）） were synthesized via reversible addition-fragmentation transfer（RAFT） emulsifier-free emulsion polymerization. Th...The gradient copolymers of acrylic acid and trifluoroethyl methacrylate（coded as P（TFEMAgrad-AA）） were synthesized via reversible addition-fragmentation transfer（RAFT） emulsifier-free emulsion polymerization. The spontaneous batch feeding approach was used to control the gradient chain sequence. Transmission electron microscopy（TEM） analysis revealed that the P（TFEMA-grad-AA） can self-assemble to form spherical micelles, rodlike micelles or vesicles in selective solvents. Morphological transition of the P（TFEMA-grad-AA） micelles was sensitive to the water content of the dioxane/water mixed solvent. More interestingly, Ag nanoparticles（NPs） were encapsulated by the P（TFEMA-grad-AA） micelles during the selfassembly process. The gradient chain sequence made the Ag NPs easily enter the core of the micelles, even when P（TFEMA-grad-AA） had less hydrophobic fluoro-units and more hydrophilic units. TEM images with energy dispersive spectrometer indicated that the nanocomposite micelles consisted of a Ag NPs core and a gradient copolymer shell.展开更多
Monomer sequence influences the properties and applications of polymers.Consequently,massive efforts have been made to implement sequence control of polymers.In this work,we developed a computer-aided droplet-flow pol...Monomer sequence influences the properties and applications of polymers.Consequently,massive efforts have been made to implement sequence control of polymers.In this work,we developed a computer-aided droplet-flow polymerization based on photo-controlled reversible-deactivation radical polymerization(photo-RDRP),enabling synthesis of gradient copolymers of tunable sequential arrangements,low dispersity and good structural fidelity from various monomers without following their intrinsic reactivities,which is a key limitation in sequence control.The obtained gradient copolymers exhibit unique thermal properties and stimulus responsiveness comparing with the random and block counterparts,and their glass transition behaviour could be regulated by the gradient tendency.We believe that the unprecedented gradient photo-RDRP based on flow synthesis opens a robust and versatile avenue to streamline the synthesis of well-defined gradient polymers,and is compatible with other polymerization mechanisms.展开更多
In this paper, a polymer spherical symmetry GRIN sphere lens were prepared by the suspension-diffusion-copolymerization(SDC) technique, selecting methyl methacrylate(MMA) as monomer M1 and acrylic 2,2,2-trifluoroethyl...In this paper, a polymer spherical symmetry GRIN sphere lens were prepared by the suspension-diffusion-copolymerization(SDC) technique, selecting methyl methacrylate(MMA) as monomer M1 and acrylic 2,2,2-trifluoroethyl ester(3FEA) as M2. The radial distribution of refractive index of the lens was measured by the shearing interference method, which demonstrated that the quadratic refractive-index distribution was formed in the sphere lens, and its Δn=0.019.展开更多
Copolymers of 1,3-butadiene and p-methylstyrene （p-MS） were synthesized via anionic polymerization. A benzophenone-potassium complex was added to tune the reactivity ratio of the two monomers, leading to random and ...Copolymers of 1,3-butadiene and p-methylstyrene （p-MS） were synthesized via anionic polymerization. A benzophenone-potassium complex was added to tune the reactivity ratio of the two monomers, leading to random and gradient composition alonglthe copolymer chain. The overall composition and microstructure could be controlled and well characterized by GPC and H-NMR. The p-MS was distributed from gradient to random with increasing the content of the benzophenone-potassium complex, and the 1,2-microstrucmre in the polybutadiene sequence increased at the same time. The hydrogenation of the copolymer of 1,3-butadiene and p-MS resulted in the corresponding saturated copolymer with well- defined structure and narrow molecular weight distribution.展开更多
Copolymerization of propylene oxide(PO)/carbon dioxide(CO_(2))and lactide(LA)is achievable to form new copolymers,combining the advantages of both poly(propylene carbonate)(PPC)and polylactide(PLA).In this study,we de...Copolymerization of propylene oxide(PO)/carbon dioxide(CO_(2))and lactide(LA)is achievable to form new copolymers,combining the advantages of both poly(propylene carbonate)(PPC)and polylactide(PLA).In this study,we designed a dinuclear Salen-Cr(Ⅲ)complex,which showed higher efficiency for copolymerization of PO/CO_(2)and LA than that of mononuclear Salen-Cr(Ⅲ)complex.Besides,we successfully obtained gradient and random copolymers of PPC-PLA in one pot.Furthermore,by adjusting reaction temperature,block ratios of PPC/PLA in copolymers were controllable(block ratio of PPC/PLA=1.0 at 40℃,while block ratio of PPC/PLA=0.5 at room temperature).While increasing the reaction temperature to 60℃,conversion of LA was much faster than that of PO so that gradient copolymers were obtained.展开更多
基金the National Natural Science Foundation of China(Nos.50803048 and 50703030)
文摘The gradient copolymers of acrylic acid and trifluoroethyl methacrylate（coded as P（TFEMAgrad-AA）） were synthesized via reversible addition-fragmentation transfer（RAFT） emulsifier-free emulsion polymerization. The spontaneous batch feeding approach was used to control the gradient chain sequence. Transmission electron microscopy（TEM） analysis revealed that the P（TFEMA-grad-AA） can self-assemble to form spherical micelles, rodlike micelles or vesicles in selective solvents. Morphological transition of the P（TFEMA-grad-AA） micelles was sensitive to the water content of the dioxane/water mixed solvent. More interestingly, Ag nanoparticles（NPs） were encapsulated by the P（TFEMA-grad-AA） micelles during the selfassembly process. The gradient chain sequence made the Ag NPs easily enter the core of the micelles, even when P（TFEMA-grad-AA） had less hydrophobic fluoro-units and more hydrophilic units. TEM images with energy dispersive spectrometer indicated that the nanocomposite micelles consisted of a Ag NPs core and a gradient copolymer shell.
基金This work was supported by the National Natural Science Foundation of China(21704016,21971044).
文摘Monomer sequence influences the properties and applications of polymers.Consequently,massive efforts have been made to implement sequence control of polymers.In this work,we developed a computer-aided droplet-flow polymerization based on photo-controlled reversible-deactivation radical polymerization(photo-RDRP),enabling synthesis of gradient copolymers of tunable sequential arrangements,low dispersity and good structural fidelity from various monomers without following their intrinsic reactivities,which is a key limitation in sequence control.The obtained gradient copolymers exhibit unique thermal properties and stimulus responsiveness comparing with the random and block counterparts,and their glass transition behaviour could be regulated by the gradient tendency.We believe that the unprecedented gradient photo-RDRP based on flow synthesis opens a robust and versatile avenue to streamline the synthesis of well-defined gradient polymers,and is compatible with other polymerization mechanisms.
文摘In this paper, a polymer spherical symmetry GRIN sphere lens were prepared by the suspension-diffusion-copolymerization(SDC) technique, selecting methyl methacrylate(MMA) as monomer M1 and acrylic 2,2,2-trifluoroethyl ester(3FEA) as M2. The radial distribution of refractive index of the lens was measured by the shearing interference method, which demonstrated that the quadratic refractive-index distribution was formed in the sphere lens, and its Δn=0.019.
基金the National Natural Science Foundation of China(Nos.51073149 and 51233005)
文摘Copolymers of 1,3-butadiene and p-methylstyrene （p-MS） were synthesized via anionic polymerization. A benzophenone-potassium complex was added to tune the reactivity ratio of the two monomers, leading to random and gradient composition alonglthe copolymer chain. The overall composition and microstructure could be controlled and well characterized by GPC and H-NMR. The p-MS was distributed from gradient to random with increasing the content of the benzophenone-potassium complex, and the 1,2-microstrucmre in the polybutadiene sequence increased at the same time. The hydrogenation of the copolymer of 1,3-butadiene and p-MS resulted in the corresponding saturated copolymer with well- defined structure and narrow molecular weight distribution.
基金financially supported by the National Key R&D Program of China (No. 2021YFA1501700)the National Natural Science Foundation of China+1 种基金Basic Science Center Program (No.51988102)the National Natural Science Foundation of China (No. 52073272)
文摘Copolymerization of propylene oxide(PO)/carbon dioxide(CO_(2))and lactide(LA)is achievable to form new copolymers,combining the advantages of both poly(propylene carbonate)(PPC)and polylactide(PLA).In this study,we designed a dinuclear Salen-Cr(Ⅲ)complex,which showed higher efficiency for copolymerization of PO/CO_(2)and LA than that of mononuclear Salen-Cr(Ⅲ)complex.Besides,we successfully obtained gradient and random copolymers of PPC-PLA in one pot.Furthermore,by adjusting reaction temperature,block ratios of PPC/PLA in copolymers were controllable(block ratio of PPC/PLA=1.0 at 40℃,while block ratio of PPC/PLA=0.5 at room temperature).While increasing the reaction temperature to 60℃,conversion of LA was much faster than that of PO so that gradient copolymers were obtained.
