The pursuit of incorporating eco-friendly reinforcing agents in polymer composites has accentuated the exploration of various natural biomass-derived materials.The burgeoning environmental crisis spurred by the discha...The pursuit of incorporating eco-friendly reinforcing agents in polymer composites has accentuated the exploration of various natural biomass-derived materials.The burgeoning environmental crisis spurred by the discharge of synthetic dyes into wastewater has catalyzed the search for effective and sustainable treatment technologies.Among the various sorbent materials explored,biochar,being renewable,has gained prominence due to its excellent adsorption properties and environmental sustainability.It has also emerged as a focal point for its potential to replace other conventional reinforcing agents,viz.,fumed silica,aluminum oxide,treated clays,etc.This study introduces a novel class of polymer nanocomposites comprising of lignin-based biochar particles and poly(ester amide urethane)matrix via a feasible method.The structural evaluation of these nanocomposites was accomplished using Fourier-transform infrared spectroscopy,X-ray photoelectron spectroscopy,and powder X-ray diffraction.The polymer nanocomposites exhibited superior mechanical properties with an increment in tensile strength factor by 45%in comparison to its pristine matrix,along with an excellent toughness value of 90.22 MJm^(−3)at a low loading amount of only 1 wt%.The composites showed excellent improvement in thermal properties with a sharp rise in the glass transition temperature(Tg)value from−28.15℃to 84℃,while also championing sustainability through inherent biodegradability attributes.Beyond their structural prowess,these polymer nanocomposites demonstrated excellent potential as adsorbents,displaying efficient removal of malachite green and tartrazine dyes from aqueous systems with a removal efficiency of 87.25%and 73.98%,respectively.The kinetics study revealed the pseudo second order model to be the precision tool to assess the dye removal study.Complementing this,the Langmuir adsorption isotherm provided a framework to assess the sorption features of the polymer nanocomposites.Overall,these renewable biochar integrated polymer matrices boast remarkable recovery capabilities up to seven cycles of usage with an excellent dye recovery percentage of 95.21%for the last cycle,thereby defining sustainability as well as economic feasibility.展开更多
AB2-type-prepolymerized monomer was rapidly （2 h） prepared at room temperature （25 ℃） using commercially available maleic anhydride （MA） and diethanolamine （DEA） as raw materials. By employing toluene-p-sulfo...AB2-type-prepolymerized monomer was rapidly （2 h） prepared at room temperature （25 ℃） using commercially available maleic anhydride （MA） and diethanolamine （DEA） as raw materials. By employing toluene-p-sulfonic acid as a catalyzer, a series of hyperbranched poly（amide-ester） （HBPAE） were successfully synthesized from prepared AB2 monomer by solution condensation polymerization through ＂one-step process＂ or ＂pseudo one-step process＂ （using pentaerythritol as a center core）. The processes were carried out at high temperature of 120 ℃ for 6 h in air atmosphere （inert protection free） with reduced pressure distillation （0.08--0.096 MPa）. The results of FT-IR, UV-Vis, TGA, and intrinsic viscosity testing by Ubbelodhe viscometer showed that the prepared HBPAEs possess three-dimensional configuration with unsaturated conjugate structure, large numbers of branches and numerous terminal hydroxyl groups. These result in their low viscosity, high solubility and thermal stability.展开更多
A novel AB3-type monomer was prepared from gallic acid and DL-2-aminobutyric acid, and used for the synthesis of the biocompatible hyperbranched poly(ester-amide)s by self-polycondensation. The polymers were character...A novel AB3-type monomer was prepared from gallic acid and DL-2-aminobutyric acid, and used for the synthesis of the biocompatible hyperbranched poly(ester-amide)s by self-polycondensation. The polymers were characterized via FTIR and NMR spectroscopy and thermal analysis, and the average degree of branching of the polymers was estimated to be 0.75. The polymers with abundant acetyl end groups were found to be amorphous with lower intrinsic viscosity, better thermal stability and excellent solubility.展开更多
A series of new optically active aromatic poly(ester amide)s containing a chiral group in the side chain prepared from the p-toluenesulfonic acid salt of o,o'-bis(leucyl)-hexanediol (TS-+LHD+TS-) and p-phthaloyl c...A series of new optically active aromatic poly(ester amide)s containing a chiral group in the side chain prepared from the p-toluenesulfonic acid salt of o,o'-bis(leucyl)-hexanediol (TS-+LHD+TS-) and p-phthaloyl chloride and styrene-2,5- dicarbonyl chloride styrene have been synthesized by interfacial polymerization. The structure of the monomer is elucidated by FT-IR and elemental analysis. The thermal properties of the polymers were studied by DSC and TGA. The chiroptical properties of the above polymer have also been studied by circular dichroism (CD) spectroscopy. Results indicated that these polymers form helical structures.展开更多
It has been proved that introducing isocyanurate into polymer chains could improve the flame retardancy of polymers.We describe in this work the synthesis and the thermal property study of three thermoplastic polyisoc...It has been proved that introducing isocyanurate into polymer chains could improve the flame retardancy of polymers.We describe in this work the synthesis and the thermal property study of three thermoplastic polyisocyanurates,which are polyisocyanuratoamide(PICA-6),polyisocyanurato(ester amide)(PICEA-6)and polyisocyanurato(urea ester)(PICUE-6).These polymers show similar and improved thermal stability with the existence of isocyanurate rings.PICA-6 is more crystalizable than the rest two and the melting temperature is found to be around 240℃ but it still crystalizes slowly.For PICEA-6 and PICUE-6,only glass transition can be observed on the DSC traces.The glass transition temperature follows the order of PICA-6>PICEA-6>PICUE-6(101.9,77.9 and 28.7℃,respectively).展开更多
A series of thermoplastic polyester elastomer (TPEE) and thermoplastic poly(ester amide)s elastomer (TPEaE)copolymers were obtained by depolymerizing PET (polyethylene terephthalate) by which the waste PET canbe effic...A series of thermoplastic polyester elastomer (TPEE) and thermoplastic poly(ester amide)s elastomer (TPEaE)copolymers were obtained by depolymerizing PET (polyethylene terephthalate) by which the waste PET canbe efficiently recovered and recycled into value-added products from a practical and economical point of view.The structure of TPEE and TPEaE was identified using nuclear magnetic resonance (NMR) and Fourier transforminfrared spectroscopy (FT-IR). Differential scanning calorimetry (DSC) data showed that the melting temperature(Tm) decreased with the amide content increased. The glass transition temperature (Tg) was increased as introducingthe amide group, and the formation of amide-ester and amide-amide hydrogen bonds increased the intermolecularchain force. The intrinsic viscosity (η) showed the tendency of increment from TPEE (0.53 dL g^(−1)) to TPEaE-5%(0.72 dL g^(−1)) due to the reinforcement of hydrogen bond and chain entanglement.展开更多
A novel lactic acid-based cross-linked poly（ester-amide） （LCPEA） was synthesized. The gel fraction of the LCPEA could be modulated by the reaction conditions and it affected the mechanical and thermal properties o...A novel lactic acid-based cross-linked poly（ester-amide） （LCPEA） was synthesized. The gel fraction of the LCPEA could be modulated by the reaction conditions and it affected the mechanical and thermal properties of the LCPEA. The tensile strength, elastic modulus and bend strength of the LCPEA of 65% gel fraction were 4.65, 136.55 and 39.63 MPa, respectively. The thermal decomposition temperature （50 wt%） of the LCPEA was around 410℃.展开更多
A new method of surface chemical modification of nano-SiO2 is proposed in this paper. In the presence of catalyst, the active hydroxyl groups on the surface of nano-SiO2 reacted with AB2-type monomer （N, N-dihydroxye...A new method of surface chemical modification of nano-SiO2 is proposed in this paper. In the presence of catalyst, the active hydroxyl groups on the surface of nano-SiO2 reacted with AB2-type monomer （N, N-dihydroxyethyl-3-amino methyl propionate） by one-step polycondensation. And the product＇s Fourer transform infrared （FTIR） graphs and transmission electron microscopy（TEM） images proved that hyperbranched poly （amine-ester） was grafted on nano-SiO2 surface successfully. Results show that the modified nano-SiO2 exhibits excellent dispersion and stability in some solvents such as alcohol and chloroform.展开更多
A new class of poly(ester-imide-ether) multiblock copolymers was synthesized by transes-terification and melt copolymerization of dimethyl terephthalate (DMT) and N-(4-carbomethoxyphenyl)-4-(carbomethoxy)-phthalimide ...A new class of poly(ester-imide-ether) multiblock copolymers was synthesized by transes-terification and melt copolymerization of dimethyl terephthalate (DMT) and N-(4-carbomethoxyphenyl)-4-(carbomethoxy)-phthalimide with ethylene glycol (EG) and polytetramethylene glycol (PTMG). The structure of the above copolymers was characterized by H-1-NMR and IR spectroscopy. Some properties of the coplymers were also examined. It was found that their mechanical properties and heat stability, compared with poly(ether-ester) copolymers, were obviously improved.展开更多
Epoxy resin based Unsaturated poly(ester-amide) resins (UPEAs) can be prepared by many methods but here these were prepared by reported method [1]. These UPEAs were then treated with acrylotl chloride to afford acryla...Epoxy resin based Unsaturated poly(ester-amide) resins (UPEAs) can be prepared by many methods but here these were prepared by reported method [1]. These UPEAs were then treated with acrylotl chloride to afford acrylated UPEAs resin (i.e. AUPEAs). Interacting blends of equal proportional AUPEAs and vinyl ester epoxy (VE) resin were prepared. APEAs and AUPEAs were characterized by elemental analysis, molecular weight determined by vapour pressure osmometer and by IR spectral study and by thermogravimetry. The curing of interacting blends was monitored on differential scanning calorimeter (DSC). Based on DSC data in situ glass reinforced composites of the resultant blends have been prepared and characterized for mechanical, electrical and chemical properties. Unreinforced blends were characterized by thermogravimetry (TGA).展开更多
With adjustable amphiphilicity and anionic/cationic charge,biodegradability and biocompatibility,amino acid-based poly(ester amide)s(PEAs)have drawn attention in the research of tissue engineered vascular grafts.In th...With adjustable amphiphilicity and anionic/cationic charge,biodegradability and biocompatibility,amino acid-based poly(ester amide)s(PEAs)have drawn attention in the research of tissue engineered vascular grafts.In this work,L-phenylalanine-based PEAs with or without L-lysine were synthesized through polycondensation,and ultrafine fibrous grafts consisted of PEAs and poly(ε-caprolactone)(PCL)in given mass ratios were further prepared via blend electrospinning.Surface characterizations by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy confirmed the chemical structure,and the wettability indicated that the prepared PCL/PEAs electrospun membranes exhibited less hydrophobic than PCL.Tensile results showed that the PCL/PEAs membranes possessed suitable mechanical properties,which could meet the requirements of artificial blood vessels.Cell culture and hemolytic tests exhibited that the PCL/PEAs electrospun membranes are biocompatible.In general,the electrospun grafts of PCL/PEAs could be applied for vascular repair.展开更多
A series of hyperbranched poly(ester-amide-ether)s (H-PEAEs) were synthesized via the A2+CB3 approach by the self-transesterification of ethyl ester-amide-ethers end-capped with three hydroxyl groups and ethyl ester g...A series of hyperbranched poly(ester-amide-ether)s (H-PEAEs) were synthesized via the A2+CB3 approach by the self-transesterification of ethyl ester-amide-ethers end-capped with three hydroxyl groups and ethyl ester group at two terminals.The molecular structures were characterized with 1H NMR and FT-IR spectroscopy.The number average molecular weights were estimated by GPC analysis to possess bimodal wide distribution from 1.57 to 2.09.The strong inherent blue fluorescence was observed at 330 nm for excitation and 390 nm for emission.Moreover,the emission intensity and fluorescence quantum yield increased along with the incorporated ether chain length,as well as almost linearly with the H-PEAE concentration in an aqueous solution.For comparing the fluorescence performance,the linear poly(ester-amide-ether) (L-PEAE) and hyperbranched poly(ester-amide) (H-PEA) were synthesized.The results showed that the coexistence of ether bond and carboxyl group in the molecular chain was essential for generating the strong fluorescence.However,the compact backbone of H-PEAE would be propitious to the enhancement of fluorescence properties.展开更多
Wound healing dressing is increasingly needed in clinical owing to the large quantity of skin damage annually.Excessive reactive oxygen species(ROS)produced through internal or external environmental influences can le...Wound healing dressing is increasingly needed in clinical owing to the large quantity of skin damage annually.Excessive reactive oxygen species(ROS)produced through internal or external environmental influences can lead to lipid peroxidation,protein denaturation,and even DNA damage,and ultimately have harmful effects on cells.Aiming to sufficiently contact with the wound microenvironment and scavenge ROS,superabsorbent poly(acrylic acid)and antioxidant poly(ester amide)(PAA/PEA)hybrid hydrogel has been developed to enhance wound healing.The physical and chemical properties of hybrid hydrogels were studied by Fourier-transform infrared(FTIR)absorption spectrum,compression,swelling,degradation,etc.Besides,the antioxidant properties of hybrid hydrogels can be investigated through the free radical scavenging experiment,and corresponding antioxidant indicators have been tested at the cellular level.Hybrid hydrogel scaffolds supported the proliferation of human umbilical vein endothelial cells and fibroblasts,as well as accelerated angiogenesis and skin regeneration in wounds.The healing properties of wounds in vivo were further assessed on mouse skin wounds.Results showed that PAA/PEA hybrid hydrogel scaffolds significantly accelerated the wound healing process through enhancing granulation formation and re-epithelialization.In summary,these superabsorbent and antioxidative hybrid hydrogels could be served as an excellent wound dressing for full-thickness wound healing.展开更多
High molecular weight aliphatic segmented poly（ether ester amide）s（PEEAs） were synthesized via melt polycondensation and chain extension. An oligomeric polyamide（PA） terminated mainly with -COOH groups（HOOC-PA-...High molecular weight aliphatic segmented poly（ether ester amide）s（PEEAs） were synthesized via melt polycondensation and chain extension. An oligomeric polyamide（PA） terminated mainly with -COOH groups（HOOC-PA-COOH） was prepared from the reaction of nylon 610 salt with sebacic acid. Melt polycondensation of HOOC-PA-COOH with polyethylene glycol（PEG）, such as PEG400, PEG600, PEG1000 and PEG1500, was conducted at 200 ℃, and several segmented PEEA prepolymers（PrePEEAs） were prepared. Chain extension of PrePEEAs was carried out at 190 ℃ using 2,2＇-（1,4-phenylene）-bis（2-oxazoline） and adipoyl biscaprolactamate as combination chain extenders. Chain extended PEEAs（ExtPEEAs） were characterized by gel permeation chromatography（GPC）, Fourier transform infrared spectrophotometer（FTIR）, proton nuclear magnetic resonance（1H NMR）, differential scanning calorimetry（DSC）, wide angle X-ray scattering（WAXS）, thermogravimetry analysis（TGA）, and tensile test. The ExtPEEAs exhibited Mn up to 98700, Tm from 164.2 ℃ to 176.1 ℃, initial decomposition temperature above 320.6 ℃, tensile strength up to 34.80 MPa, and strain at break from 111.92% to 353.12%. Aliphatic segmented PEEAs with good thermal and mechanical properties were prepared.展开更多
A pseudo AB 2 monomer,N-(2-acetoxyl ethyl)-N-(2′,4′-dicarboxylic benzoyl) amine (F 2),was synthesized by two steps.Firstly the ring-opening reaction of 1,2,4-benzenetricarboxylic anhydride was carried out with ethan...A pseudo AB 2 monomer,N-(2-acetoxyl ethyl)-N-(2′,4′-dicarboxylic benzoyl) amine (F 2),was synthesized by two steps.Firstly the ring-opening reaction of 1,2,4-benzenetricarboxylic anhydride was carried out with ethanolamine resulting in N-(2-hydroxyl ethyl)-N-(2′,4′-dicarboxylic benzoyl) amine (F 1),and then F 1 was acetylized by acetic anhydride to afford F 2.The yields for F 1 and F 2 are 90% and 84.5%,respectively.By bulk polycondensation of F 2 catalyzed by Zn(OAc) 2,a novel hyperbranched poly(ester-amide) was effectively prepared in a yield of 92%.The structure of the product was characterized by mean of IR, 1H-NMR,DSC and TGA.The obtained polymer has good thermal properties as expected.The effect of the polymer on the rheological behavior of polycarbonate (PC) was studied by using Haake Rheomix 600.It was shown that the torque of melt PC was reduced by 70% with the addition of 5wt% of the obtained hyperbranched poly(ester-amide).展开更多
文摘The pursuit of incorporating eco-friendly reinforcing agents in polymer composites has accentuated the exploration of various natural biomass-derived materials.The burgeoning environmental crisis spurred by the discharge of synthetic dyes into wastewater has catalyzed the search for effective and sustainable treatment technologies.Among the various sorbent materials explored,biochar,being renewable,has gained prominence due to its excellent adsorption properties and environmental sustainability.It has also emerged as a focal point for its potential to replace other conventional reinforcing agents,viz.,fumed silica,aluminum oxide,treated clays,etc.This study introduces a novel class of polymer nanocomposites comprising of lignin-based biochar particles and poly(ester amide urethane)matrix via a feasible method.The structural evaluation of these nanocomposites was accomplished using Fourier-transform infrared spectroscopy,X-ray photoelectron spectroscopy,and powder X-ray diffraction.The polymer nanocomposites exhibited superior mechanical properties with an increment in tensile strength factor by 45%in comparison to its pristine matrix,along with an excellent toughness value of 90.22 MJm^(−3)at a low loading amount of only 1 wt%.The composites showed excellent improvement in thermal properties with a sharp rise in the glass transition temperature(Tg)value from−28.15℃to 84℃,while also championing sustainability through inherent biodegradability attributes.Beyond their structural prowess,these polymer nanocomposites demonstrated excellent potential as adsorbents,displaying efficient removal of malachite green and tartrazine dyes from aqueous systems with a removal efficiency of 87.25%and 73.98%,respectively.The kinetics study revealed the pseudo second order model to be the precision tool to assess the dye removal study.Complementing this,the Langmuir adsorption isotherm provided a framework to assess the sorption features of the polymer nanocomposites.Overall,these renewable biochar integrated polymer matrices boast remarkable recovery capabilities up to seven cycles of usage with an excellent dye recovery percentage of 95.21%for the last cycle,thereby defining sustainability as well as economic feasibility.
基金the National Science and Technology Support Project of "the Eleventh Five-year Plan"(2006BAE03B06-03)the New Century Talents Support Program of Chinese Education Department (NCET-04-0614)
文摘AB2-type-prepolymerized monomer was rapidly （2 h） prepared at room temperature （25 ℃） using commercially available maleic anhydride （MA） and diethanolamine （DEA） as raw materials. By employing toluene-p-sulfonic acid as a catalyzer, a series of hyperbranched poly（amide-ester） （HBPAE） were successfully synthesized from prepared AB2 monomer by solution condensation polymerization through ＂one-step process＂ or ＂pseudo one-step process＂ （using pentaerythritol as a center core）. The processes were carried out at high temperature of 120 ℃ for 6 h in air atmosphere （inert protection free） with reduced pressure distillation （0.08--0.096 MPa）. The results of FT-IR, UV-Vis, TGA, and intrinsic viscosity testing by Ubbelodhe viscometer showed that the prepared HBPAEs possess three-dimensional configuration with unsaturated conjugate structure, large numbers of branches and numerous terminal hydroxyl groups. These result in their low viscosity, high solubility and thermal stability.
文摘A novel AB3-type monomer was prepared from gallic acid and DL-2-aminobutyric acid, and used for the synthesis of the biocompatible hyperbranched poly(ester-amide)s by self-polycondensation. The polymers were characterized via FTIR and NMR spectroscopy and thermal analysis, and the average degree of branching of the polymers was estimated to be 0.75. The polymers with abundant acetyl end groups were found to be amorphous with lower intrinsic viscosity, better thermal stability and excellent solubility.
基金This work was supported by the National Natural Science Foundation of China (No. 20134010,20274003).
文摘A series of new optically active aromatic poly(ester amide)s containing a chiral group in the side chain prepared from the p-toluenesulfonic acid salt of o,o'-bis(leucyl)-hexanediol (TS-+LHD+TS-) and p-phthaloyl chloride and styrene-2,5- dicarbonyl chloride styrene have been synthesized by interfacial polymerization. The structure of the monomer is elucidated by FT-IR and elemental analysis. The thermal properties of the polymers were studied by DSC and TGA. The chiroptical properties of the above polymer have also been studied by circular dichroism (CD) spectroscopy. Results indicated that these polymers form helical structures.
基金the financial supports to this work by the National Natural Science Foundation of China(Nos.21404040,21734004,51573061)the Fund of the Key Laboratory of Luminescence from Molecular Aggregates of Guangdong Province,Guangzhou 510640,China(South China University of Technology,No.2019B030301003)the Opening Project Funding of Key Laboratory of Polymer Processing Engineering(South China University of Technology),Ministry of Education,China(No.KFKT1702).
文摘It has been proved that introducing isocyanurate into polymer chains could improve the flame retardancy of polymers.We describe in this work the synthesis and the thermal property study of three thermoplastic polyisocyanurates,which are polyisocyanuratoamide(PICA-6),polyisocyanurato(ester amide)(PICEA-6)and polyisocyanurato(urea ester)(PICUE-6).These polymers show similar and improved thermal stability with the existence of isocyanurate rings.PICA-6 is more crystalizable than the rest two and the melting temperature is found to be around 240℃ but it still crystalizes slowly.For PICEA-6 and PICUE-6,only glass transition can be observed on the DSC traces.The glass transition temperature follows the order of PICA-6>PICEA-6>PICUE-6(101.9,77.9 and 28.7℃,respectively).
基金This research was funded by the Ministry of Science and Technology of Taiwan,Grant No.MOST 109-2634-F-027-001.
文摘A series of thermoplastic polyester elastomer (TPEE) and thermoplastic poly(ester amide)s elastomer (TPEaE)copolymers were obtained by depolymerizing PET (polyethylene terephthalate) by which the waste PET canbe efficiently recovered and recycled into value-added products from a practical and economical point of view.The structure of TPEE and TPEaE was identified using nuclear magnetic resonance (NMR) and Fourier transforminfrared spectroscopy (FT-IR). Differential scanning calorimetry (DSC) data showed that the melting temperature(Tm) decreased with the amide content increased. The glass transition temperature (Tg) was increased as introducingthe amide group, and the formation of amide-ester and amide-amide hydrogen bonds increased the intermolecularchain force. The intrinsic viscosity (η) showed the tendency of increment from TPEE (0.53 dL g^(−1)) to TPEaE-5%(0.72 dL g^(−1)) due to the reinforcement of hydrogen bond and chain entanglement.
文摘A novel lactic acid-based cross-linked poly（ester-amide） （LCPEA） was synthesized. The gel fraction of the LCPEA could be modulated by the reaction conditions and it affected the mechanical and thermal properties of the LCPEA. The tensile strength, elastic modulus and bend strength of the LCPEA of 65% gel fraction were 4.65, 136.55 and 39.63 MPa, respectively. The thermal decomposition temperature （50 wt%） of the LCPEA was around 410℃.
基金Sponsored by the Ministerial Level Advanced Research Foundation (120701BQ0126)
文摘A new method of surface chemical modification of nano-SiO2 is proposed in this paper. In the presence of catalyst, the active hydroxyl groups on the surface of nano-SiO2 reacted with AB2-type monomer （N, N-dihydroxyethyl-3-amino methyl propionate） by one-step polycondensation. And the product＇s Fourer transform infrared （FTIR） graphs and transmission electron microscopy（TEM） images proved that hyperbranched poly （amine-ester） was grafted on nano-SiO2 surface successfully. Results show that the modified nano-SiO2 exhibits excellent dispersion and stability in some solvents such as alcohol and chloroform.
基金This work was supported by 863 Programme of China (No. 715-004-0010).
文摘A new class of poly(ester-imide-ether) multiblock copolymers was synthesized by transes-terification and melt copolymerization of dimethyl terephthalate (DMT) and N-(4-carbomethoxyphenyl)-4-(carbomethoxy)-phthalimide with ethylene glycol (EG) and polytetramethylene glycol (PTMG). The structure of the above copolymers was characterized by H-1-NMR and IR spectroscopy. Some properties of the coplymers were also examined. It was found that their mechanical properties and heat stability, compared with poly(ether-ester) copolymers, were obviously improved.
文摘Epoxy resin based Unsaturated poly(ester-amide) resins (UPEAs) can be prepared by many methods but here these were prepared by reported method [1]. These UPEAs were then treated with acrylotl chloride to afford acrylated UPEAs resin (i.e. AUPEAs). Interacting blends of equal proportional AUPEAs and vinyl ester epoxy (VE) resin were prepared. APEAs and AUPEAs were characterized by elemental analysis, molecular weight determined by vapour pressure osmometer and by IR spectral study and by thermogravimetry. The curing of interacting blends was monitored on differential scanning calorimeter (DSC). Based on DSC data in situ glass reinforced composites of the resultant blends have been prepared and characterized for mechanical, electrical and chemical properties. Unreinforced blends were characterized by thermogravimetry (TGA).
基金supported by the National Natural Science Foundation of China(No.52073204).
文摘With adjustable amphiphilicity and anionic/cationic charge,biodegradability and biocompatibility,amino acid-based poly(ester amide)s(PEAs)have drawn attention in the research of tissue engineered vascular grafts.In this work,L-phenylalanine-based PEAs with or without L-lysine were synthesized through polycondensation,and ultrafine fibrous grafts consisted of PEAs and poly(ε-caprolactone)(PCL)in given mass ratios were further prepared via blend electrospinning.Surface characterizations by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy confirmed the chemical structure,and the wettability indicated that the prepared PCL/PEAs electrospun membranes exhibited less hydrophobic than PCL.Tensile results showed that the PCL/PEAs membranes possessed suitable mechanical properties,which could meet the requirements of artificial blood vessels.Cell culture and hemolytic tests exhibited that the PCL/PEAs electrospun membranes are biocompatible.In general,the electrospun grafts of PCL/PEAs could be applied for vascular repair.
基金support of the National Natural Science Foundation of China(50633010) is gratefully acknowledged
文摘A series of hyperbranched poly(ester-amide-ether)s (H-PEAEs) were synthesized via the A2+CB3 approach by the self-transesterification of ethyl ester-amide-ethers end-capped with three hydroxyl groups and ethyl ester group at two terminals.The molecular structures were characterized with 1H NMR and FT-IR spectroscopy.The number average molecular weights were estimated by GPC analysis to possess bimodal wide distribution from 1.57 to 2.09.The strong inherent blue fluorescence was observed at 330 nm for excitation and 390 nm for emission.Moreover,the emission intensity and fluorescence quantum yield increased along with the incorporated ether chain length,as well as almost linearly with the H-PEAE concentration in an aqueous solution.For comparing the fluorescence performance,the linear poly(ester-amide-ether) (L-PEAE) and hyperbranched poly(ester-amide) (H-PEA) were synthesized.The results showed that the coexistence of ether bond and carboxyl group in the molecular chain was essential for generating the strong fluorescence.However,the compact backbone of H-PEAE would be propitious to the enhancement of fluorescence properties.
基金This work sincerely acknowledges the support from the Science and Technology Planning Project of Shenzhen(JCYJ20190813153409172)Chunhui Project from Education Ministry of China(Z2016125)+1 种基金Sichuan Science and Technology Program(2019YFG0251,2019JDTD0024)Young scholars for reserve talents of Xihua University.
文摘Wound healing dressing is increasingly needed in clinical owing to the large quantity of skin damage annually.Excessive reactive oxygen species(ROS)produced through internal or external environmental influences can lead to lipid peroxidation,protein denaturation,and even DNA damage,and ultimately have harmful effects on cells.Aiming to sufficiently contact with the wound microenvironment and scavenge ROS,superabsorbent poly(acrylic acid)and antioxidant poly(ester amide)(PAA/PEA)hybrid hydrogel has been developed to enhance wound healing.The physical and chemical properties of hybrid hydrogels were studied by Fourier-transform infrared(FTIR)absorption spectrum,compression,swelling,degradation,etc.Besides,the antioxidant properties of hybrid hydrogels can be investigated through the free radical scavenging experiment,and corresponding antioxidant indicators have been tested at the cellular level.Hybrid hydrogel scaffolds supported the proliferation of human umbilical vein endothelial cells and fibroblasts,as well as accelerated angiogenesis and skin regeneration in wounds.The healing properties of wounds in vivo were further assessed on mouse skin wounds.Results showed that PAA/PEA hybrid hydrogel scaffolds significantly accelerated the wound healing process through enhancing granulation formation and re-epithelialization.In summary,these superabsorbent and antioxidative hybrid hydrogels could be served as an excellent wound dressing for full-thickness wound healing.
基金Supported by the National Natural Science Foundation of China（Nos.21244006, 50873013）.
文摘High molecular weight aliphatic segmented poly（ether ester amide）s（PEEAs） were synthesized via melt polycondensation and chain extension. An oligomeric polyamide（PA） terminated mainly with -COOH groups（HOOC-PA-COOH） was prepared from the reaction of nylon 610 salt with sebacic acid. Melt polycondensation of HOOC-PA-COOH with polyethylene glycol（PEG）, such as PEG400, PEG600, PEG1000 and PEG1500, was conducted at 200 ℃, and several segmented PEEA prepolymers（PrePEEAs） were prepared. Chain extension of PrePEEAs was carried out at 190 ℃ using 2,2＇-（1,4-phenylene）-bis（2-oxazoline） and adipoyl biscaprolactamate as combination chain extenders. Chain extended PEEAs（ExtPEEAs） were characterized by gel permeation chromatography（GPC）, Fourier transform infrared spectrophotometer（FTIR）, proton nuclear magnetic resonance（1H NMR）, differential scanning calorimetry（DSC）, wide angle X-ray scattering（WAXS）, thermogravimetry analysis（TGA）, and tensile test. The ExtPEEAs exhibited Mn up to 98700, Tm from 164.2 ℃ to 176.1 ℃, initial decomposition temperature above 320.6 ℃, tensile strength up to 34.80 MPa, and strain at break from 111.92% to 353.12%. Aliphatic segmented PEEAs with good thermal and mechanical properties were prepared.
文摘A pseudo AB 2 monomer,N-(2-acetoxyl ethyl)-N-(2′,4′-dicarboxylic benzoyl) amine (F 2),was synthesized by two steps.Firstly the ring-opening reaction of 1,2,4-benzenetricarboxylic anhydride was carried out with ethanolamine resulting in N-(2-hydroxyl ethyl)-N-(2′,4′-dicarboxylic benzoyl) amine (F 1),and then F 1 was acetylized by acetic anhydride to afford F 2.The yields for F 1 and F 2 are 90% and 84.5%,respectively.By bulk polycondensation of F 2 catalyzed by Zn(OAc) 2,a novel hyperbranched poly(ester-amide) was effectively prepared in a yield of 92%.The structure of the product was characterized by mean of IR, 1H-NMR,DSC and TGA.The obtained polymer has good thermal properties as expected.The effect of the polymer on the rheological behavior of polycarbonate (PC) was studied by using Haake Rheomix 600.It was shown that the torque of melt PC was reduced by 70% with the addition of 5wt% of the obtained hyperbranched poly(ester-amide).
