The evolution of high-frequency communication has accentuated the significance of controlling dielectric properties in polymer media.Traditionally,it has been theorized that rigid molecular chains lead to lower dielec...The evolution of high-frequency communication has accentuated the significance of controlling dielectric properties in polymer media.Traditionally,it has been theorized that rigid molecular chains lead to lower dielectric loss.However,the validity of this proposition at high frequencies remains uncertain.To scrutinize the correlation between chain flexibility and dielectric properties,we synthesized six poly(ester imide)s(PEIs)with systematically varied molecular chain flexibilities by modifying the ester's substitution on the aromatic ring.The introduction of ester bonds bestowed all PEI films with a low dielectric dissipation factor(D_(f)),ranging from 0.0021 to 0.0038 at 10 GHz in dry conditions.The dry D_(f)displayed a pattern consistent with volume polarizability(P/V).Unexpectedly,PI-mmm-T,featu ring the most flexible molecular chain,exhibited the lowest dielectric loss under both dry(0.0021@10 GHz)and hygroscopic(0.0029@10 GHz)conditions.Furthermore,the observed increase in D_(f)after humidity absorption suggests that the high dielectric loss of PEI in applications may be attributed to its hygroscopic nature.Molecular simulations and characterization of the aggregation structure revealed that the smaller cavities within flexible molecular chains,after close stacking,impede the entry of water molecules.Despite sacrificing high-temperature resistance,the precursor exhibited enhanced solubility properties and could be processed into high-quality films.Our research unveils new insights into the relationship between flexibility and highfrequency dielectric loss,offering innovative perspectives on synthesizing aromatic polymers with exceptional dielectric properties.展开更多
The clinical efficacy of chemotherapeutic drugs is hindered by their poor aqueous solubility, low bioavailability and severe side effects. In recent years, polymeric nanocarriers have been used for drug delivery to im...The clinical efficacy of chemotherapeutic drugs is hindered by their poor aqueous solubility, low bioavailability and severe side effects. In recent years, polymeric nanocarriers have been used for drug delivery to improve the efficacy of many chemotherapeutics. In this study, a series of biodegradable phenylalaninebased poly(ester amide)(Phe-PEA) with tunable molecular weights(MWs) were synthesized to systematically investigate the relationship between the polymer MW and the efficacy of the corresponding polymeric nanoparticles(NPs). The results indicated that a range of polymers with different MWs can be obtained by varying the monomer ratio or reaction time. Doxorubicin(DOX), a classic clinical lymphoma treatment strategy, was selected as a model drug. The loading capacity and stability of the higher MW polymeric NPs were superior to those of the lower MW ones. Moreover, in vitro and in vivo data revealed that high MW polymeric NPs had better anticancer efficacy against lymphoma and higher biosafety than low MW polymeric nanoparticles and DOX. Therefore, this study suggests the importance of polymer MW for drug delivery systems and provides valuable guidance for the design of enhanced polymeric drug carriers for lymphoma treatment.展开更多
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 matric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 simple non-isocyanate route is developed for synthesizing crystallizable aliphatic thermoplastic poly（ester urethane） elastomers （TPEURs） with good thermal and mechanical properties. Three prepolymers of 1,6-bis...A simple non-isocyanate route is developed for synthesizing crystallizable aliphatic thermoplastic poly（ester urethane） elastomers （TPEURs） with good thermal and mechanical properties. Three prepolymers of 1,6-bis（hydroxyethyloxycarbonylamino） hexane （BHCH）, i.e. PrePBHCHs, were prepared through the self-transurethane polycondensation of BHCH. A poly（butylene adipate） prepolymer （PrePBA） with terminal HO-- groups was prepared and used as a polyester glycol. A series of TPEURs were prepared by the co-polycondensation of the PrePBHCHs with PrePBA at 170 ℃under a reduced pressure of 399 Pa. The TPEURs were characterized by gel permeation chromatography, FTIR, 1H-NMR, differential scanning calorimetry, thermogravimetric analysis, wide-angle X-ray diffraction, atomic force microscopy, and tensile test. The TPEURs exhibited Mn up to 23300 g/mol, Mw up to 51100 g/mol, Tg ranging from -33.8 ℃ to -3.1 ℃, Tm from 94.3 ℃ to 111.9 ℃, initial decomposition temperature over 274.7℃, tensile strength up to18.8 MPa with a strain at break of 450.0%, and resilience up to 77.5%. TPU elastomers with good crystallization and mechanical properties were obtained through a non-isocyanate route.展开更多
Mismatched biomechanical properties between artificial vascular grafts and native blood vessels can result in intimal hyperplasia,especially for the implantation of small-diameter blood vessels.Ideal biomaterials for ...Mismatched biomechanical properties between artificial vascular grafts and native blood vessels can result in intimal hyperplasia,especially for the implantation of small-diameter blood vessels.Ideal biomaterials for vascular repair still remain challenged.Biodegradable poly(ε-caprolactone)(PCL)has been applied for the preparation of electrospun vascular grafts,but more efforts are needed to improve its compliance with tissue growth.Herein,L-arginine-based poly(ester urethane)urea(PEUU)with both elasticity and biodegradability was synthesized so as to enhance the biomechanical properties of vascular grafts by blending electrospinning with PCL in a given mass ratio.It was exhibited that the prepared electrospun PCL/PEUU fibrous membranes were suitable for cell proliferation with normal cell morphology.More importantly,the electrospun membrane with 1/1 mass ratio of PCL/PEUU(PEUU50)showed specific flexibility,exhibiting more suitable mechanical properties matching to the native blood vessels.Specifically,the PEUU50 electrospun membrane demonstrated significantly lower Young’s modulus(9.3±0.8 MPa)and tensile strength(6.0±0.5 MPa),and extremely higher elongation(389%±24%)in wet state than those(16.3±3.0 MPa,11.4±7.1 MPa and 196%±57%,respectively)of the pristine PCL membrane.Overall,this study demonstrated the great potential of amino acid-based PEUUs for the application in small-diameter vascular grafts.展开更多
A series of non-isocyanate linear high molecular weight poly(ester urethane)s(PETUs)were prepared through an environmentallyfriendly route based on dimethyl carbonate,1,6-hexanediol and 1,6-hexanediamine.In this route...A series of non-isocyanate linear high molecular weight poly(ester urethane)s(PETUs)were prepared through an environmentallyfriendly route based on dimethyl carbonate,1,6-hexanediol and 1,6-hexanediamine.In this route,the polyurethane diol was first prepared by the reaction between bis-1,6-hexamethylencarbamate(BHC)and 1,6-hexanediol.A series of polyester soft segments of polyurethane have been synthesized from the polycondensation of adipic acid and different diols,including butanediol,hexanediol,octanediol and decanediol.The subsequent polycondensation of polyurethane diol and polyester diol led to linear PETUs.The resultant polymers were characterized by GPC,FTIR,^(1)H-NMR,^(13)C-NMR,DSC,WAXD,TGA and tensile test.The results indicated that PETUs possess weight-average molecular weights higher than 1×10^(5) and the tensile strength as high as 10 MPa.The thermal properties,crystallization behavior,microphase separation behavior and morphology were studied by DSC and AFM,and the results indicated that the degree of phase separation was affected by two factors,the crystallization and hydrogen bonding interaction between soft segment and hard segment.展开更多
Prostate cancer(PCa)is the second most commonly diagnosed cancer in men.The Rac1-GTP inhibitor NSC23766 has been shown to suppress PCa growth.However,these therapies have low tumor-targeting efficacy in vivo.Therefore...Prostate cancer(PCa)is the second most commonly diagnosed cancer in men.The Rac1-GTP inhibitor NSC23766 has been shown to suppress PCa growth.However,these therapies have low tumor-targeting efficacy in vivo.Therefore,it is essential to produce a drug delivery system that specifically targets the tumor site.Herein,novel l-phenylalanine-based poly(ester amide)(Phe-PEA)polymers were synthesized and loaded with NSC23766(NSC23766@8P6 NPs),which had a small particle size(162.3±6.7nm)and high NSC23766 loading(8.0%±1.1%)with a more rapid release of NSC23766 at pH 5.0.In vitro cellu-lar uptake and cytotoxicity assays demonstrated that NSC23766@8P6 NPs were rapidly taken up by PC3 cells and showed significant effects of PCa cell proliferation inhibition and G2/M phase arrest.Further-more,in vivo studies using PC3-bearing mice demonstrated that NSC23766@8P6 NPs delivered by in-travenous injection not only increased the drug concentration with prolonged retention(96h)at the tumor site,but also inhibited tumor growth and induced apoptosis.In conclusion,we have discovered that NSC23766@8P6 NPs can serve as a delivery system that targets the tumor site and is therefore a promising therapeutic approach for PCa treatment.展开更多
Two novel amphiphilic poly(ester amine) dendrimers were synthesized and characterized by 1H NMR, 13 C NMR and IR spectra. Their properties of Langmuir film were investigated at the air/water interface....Two novel amphiphilic poly(ester amine) dendrimers were synthesized and characterized by 1H NMR, 13 C NMR and IR spectra. Their properties of Langmuir film were investigated at the air/water interface. The relationship between the surface pressure and area isotherms of the dendrimers was found to be dependent on the nature of subphases. Interaction between HgCl 2 and the dendrimers was observed, indicating that the amphiphilic dendrimers could act as a sensor for Hg 2+ .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
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
The aromatic hyperbranched poly（ester amines）（AHPEAs） were successfully synthesized via the mild condensation of N-4-cyanobenzyl diethanolamine hydrogenchloride as an AB2 monomer in concentrated HCI. The polymeriz...The aromatic hyperbranched poly（ester amines）（AHPEAs） were successfully synthesized via the mild condensation of N-4-cyanobenzyl diethanolamine hydrogenchloride as an AB2 monomer in concentrated HCI. The polymerization was monitored by FTIR to suppose the reasonable reaction mechanism. The degree of branching was determined to be 0.55 by 1H NMR with an increased conversion of up to 96%. The glass transition temperature was measured by differential scanning calorimetry to range from -19 to 15℃ The molecular weights and polydispersities were investigated by gel permeation chromatography.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
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 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
Hyperbranched poly(ester-amine) with terminal amine groups was synthesized by Michael addition reaction between trimethylolpropanetriacrylate (B 3 monomer) and pizine (A 2 monomer) under molar ratio of 6∶13 via a one...Hyperbranched poly(ester-amine) with terminal amine groups was synthesized by Michael addition reaction between trimethylolpropanetriacrylate (B 3 monomer) and pizine (A 2 monomer) under molar ratio of 6∶13 via a one-step procedure.It was further modified by stearyl chloride to form an amphiphilic hyperbranched polymer.The structures of these polymers were characterized by FT-IR,{}+1H-NMR,DSC and GPC analyses.Due to the existence of interior secondary amines,the modified polymer can be used as phase transferring agent to extract methylic orange from water layer to CHCl-3 layer.Both higher transferring capability and higher transferring rate were achieved at lower pH of the water phase.The extracted dye in the organic layer can be further released to the water layer under a basic condition.A possible mechanism for extracting dye by amphiphilic hyperbranched polymer was suggested.展开更多
基金financially supported by the National Natural Science Foundation of China(No.52303010)Key-Area Research and Development Program of Guangdong province(No.2019B010941001)+2 种基金Key Technology of Liquid Crystal Polymer Material for 5G/6G High Frequency Communication(No.JSGGZD20220822095201003)Songshan Lake Materials Laboratory(No.2021SLABFK01)the Guangdong Basic and Applied Basic Research Foundation(No.2021A1515110143)。
文摘The evolution of high-frequency communication has accentuated the significance of controlling dielectric properties in polymer media.Traditionally,it has been theorized that rigid molecular chains lead to lower dielectric loss.However,the validity of this proposition at high frequencies remains uncertain.To scrutinize the correlation between chain flexibility and dielectric properties,we synthesized six poly(ester imide)s(PEIs)with systematically varied molecular chain flexibilities by modifying the ester's substitution on the aromatic ring.The introduction of ester bonds bestowed all PEI films with a low dielectric dissipation factor(D_(f)),ranging from 0.0021 to 0.0038 at 10 GHz in dry conditions.The dry D_(f)displayed a pattern consistent with volume polarizability(P/V).Unexpectedly,PI-mmm-T,featu ring the most flexible molecular chain,exhibited the lowest dielectric loss under both dry(0.0021@10 GHz)and hygroscopic(0.0029@10 GHz)conditions.Furthermore,the observed increase in D_(f)after humidity absorption suggests that the high dielectric loss of PEI in applications may be attributed to its hygroscopic nature.Molecular simulations and characterization of the aggregation structure revealed that the smaller cavities within flexible molecular chains,after close stacking,impede the entry of water molecules.Despite sacrificing high-temperature resistance,the precursor exhibited enhanced solubility properties and could be processed into high-quality films.Our research unveils new insights into the relationship between flexibility and highfrequency dielectric loss,offering innovative perspectives on synthesizing aromatic polymers with exceptional dielectric properties.
基金supported by the National Natural Science Foundation of China (Nos. 51973243 and 52173150)International Cooperation and Exchange of the National Natural Science Foundation of China (No. 51820105004)+3 种基金China Postdoctoral Science Foundation(No. 2020M683058)Shenzhen Science and Technology Program(No. RCBS20210706092411033)the Science and Technology Planning Project of Shenzhen (No. JCYJ20190807155801657)Guangdong Innovative and Entrepreneurial Research Team Program (No.2016ZT06S029)。
文摘The clinical efficacy of chemotherapeutic drugs is hindered by their poor aqueous solubility, low bioavailability and severe side effects. In recent years, polymeric nanocarriers have been used for drug delivery to improve the efficacy of many chemotherapeutics. In this study, a series of biodegradable phenylalaninebased poly(ester amide)(Phe-PEA) with tunable molecular weights(MWs) were synthesized to systematically investigate the relationship between the polymer MW and the efficacy of the corresponding polymeric nanoparticles(NPs). The results indicated that a range of polymers with different MWs can be obtained by varying the monomer ratio or reaction time. Doxorubicin(DOX), a classic clinical lymphoma treatment strategy, was selected as a model drug. The loading capacity and stability of the higher MW polymeric NPs were superior to those of the lower MW ones. Moreover, in vitro and in vivo data revealed that high MW polymeric NPs had better anticancer efficacy against lymphoma and higher biosafety than low MW polymeric nanoparticles and DOX. Therefore, this study suggests the importance of polymer MW for drug delivery systems and provides valuable guidance for the design of enhanced polymeric drug carriers for lymphoma treatment.
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 matric
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financially supported by the National Natural Science Foundation of China(Nos.21244006 and 50873013)
文摘A simple non-isocyanate route is developed for synthesizing crystallizable aliphatic thermoplastic poly（ester urethane） elastomers （TPEURs） with good thermal and mechanical properties. Three prepolymers of 1,6-bis（hydroxyethyloxycarbonylamino） hexane （BHCH）, i.e. PrePBHCHs, were prepared through the self-transurethane polycondensation of BHCH. A poly（butylene adipate） prepolymer （PrePBA） with terminal HO-- groups was prepared and used as a polyester glycol. A series of TPEURs were prepared by the co-polycondensation of the PrePBHCHs with PrePBA at 170 ℃under a reduced pressure of 399 Pa. The TPEURs were characterized by gel permeation chromatography, FTIR, 1H-NMR, differential scanning calorimetry, thermogravimetric analysis, wide-angle X-ray diffraction, atomic force microscopy, and tensile test. The TPEURs exhibited Mn up to 23300 g/mol, Mw up to 51100 g/mol, Tg ranging from -33.8 ℃ to -3.1 ℃, Tm from 94.3 ℃ to 111.9 ℃, initial decomposition temperature over 274.7℃, tensile strength up to18.8 MPa with a strain at break of 450.0%, and resilience up to 77.5%. TPU elastomers with good crystallization and mechanical properties were obtained through a non-isocyanate route.
基金supported by the National Natural Science Foundation of China(Grant No.52073204)。
文摘Mismatched biomechanical properties between artificial vascular grafts and native blood vessels can result in intimal hyperplasia,especially for the implantation of small-diameter blood vessels.Ideal biomaterials for vascular repair still remain challenged.Biodegradable poly(ε-caprolactone)(PCL)has been applied for the preparation of electrospun vascular grafts,but more efforts are needed to improve its compliance with tissue growth.Herein,L-arginine-based poly(ester urethane)urea(PEUU)with both elasticity and biodegradability was synthesized so as to enhance the biomechanical properties of vascular grafts by blending electrospinning with PCL in a given mass ratio.It was exhibited that the prepared electrospun PCL/PEUU fibrous membranes were suitable for cell proliferation with normal cell morphology.More importantly,the electrospun membrane with 1/1 mass ratio of PCL/PEUU(PEUU50)showed specific flexibility,exhibiting more suitable mechanical properties matching to the native blood vessels.Specifically,the PEUU50 electrospun membrane demonstrated significantly lower Young’s modulus(9.3±0.8 MPa)and tensile strength(6.0±0.5 MPa),and extremely higher elongation(389%±24%)in wet state than those(16.3±3.0 MPa,11.4±7.1 MPa and 196%±57%,respectively)of the pristine PCL membrane.Overall,this study demonstrated the great potential of amino acid-based PEUUs for the application in small-diameter vascular grafts.
基金the National Natural Science Foundation of China(Nos.52173009,81971711,21574137,51373186)Beijing Natural Science Foundation(No.2192065)National Key R&D Program of China(No.2016YFB1100800)。
文摘A series of non-isocyanate linear high molecular weight poly(ester urethane)s(PETUs)were prepared through an environmentallyfriendly route based on dimethyl carbonate,1,6-hexanediol and 1,6-hexanediamine.In this route,the polyurethane diol was first prepared by the reaction between bis-1,6-hexamethylencarbamate(BHC)and 1,6-hexanediol.A series of polyester soft segments of polyurethane have been synthesized from the polycondensation of adipic acid and different diols,including butanediol,hexanediol,octanediol and decanediol.The subsequent polycondensation of polyurethane diol and polyester diol led to linear PETUs.The resultant polymers were characterized by GPC,FTIR,^(1)H-NMR,^(13)C-NMR,DSC,WAXD,TGA and tensile test.The results indicated that PETUs possess weight-average molecular weights higher than 1×10^(5) and the tensile strength as high as 10 MPa.The thermal properties,crystallization behavior,microphase separation behavior and morphology were studied by DSC and AFM,and the results indicated that the degree of phase separation was affected by two factors,the crystallization and hydrogen bonding interaction between soft segment and hard segment.
基金Supported by the National Natural Science Foun-dation of China(Nos.81672550,81974395)Guangdong Basic and Applied Basic Research Foundation(No.2019A1515011437)+7 种基金In-ternational Science and Technology Cooperation Project Plan of Guangdong Province(No.2021A0505030085)Sun Yat-sen Uni-versity Clinical Research 5010 Program(No.2019005)Sun Yat-sen Clinical Research Cultivating Program(No.201702)Guang-dong Province Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation(No.2020B1212060018OF006)Guangdong Provincial Clinical Research Center for Urological Diseases(No.2020B1111170006)to Hai Huang,the National Natural Science Foundation of China(No.51973243)Fundamental Research Funds for the Central Universities(No.191gzd35)International Coop-eration and Exchange of the National Natural Science Founda-tion of China(No.51820105004),Shenzhen Basic Research Project(No.JCYJ20190807155801657)the Project for Science&Technology New Star of Zhujiang in Guangzhou City(No.201906010082).
文摘Prostate cancer(PCa)is the second most commonly diagnosed cancer in men.The Rac1-GTP inhibitor NSC23766 has been shown to suppress PCa growth.However,these therapies have low tumor-targeting efficacy in vivo.Therefore,it is essential to produce a drug delivery system that specifically targets the tumor site.Herein,novel l-phenylalanine-based poly(ester amide)(Phe-PEA)polymers were synthesized and loaded with NSC23766(NSC23766@8P6 NPs),which had a small particle size(162.3±6.7nm)and high NSC23766 loading(8.0%±1.1%)with a more rapid release of NSC23766 at pH 5.0.In vitro cellu-lar uptake and cytotoxicity assays demonstrated that NSC23766@8P6 NPs were rapidly taken up by PC3 cells and showed significant effects of PCa cell proliferation inhibition and G2/M phase arrest.Further-more,in vivo studies using PC3-bearing mice demonstrated that NSC23766@8P6 NPs delivered by in-travenous injection not only increased the drug concentration with prolonged retention(96h)at the tumor site,but also inhibited tumor growth and induced apoptosis.In conclusion,we have discovered that NSC23766@8P6 NPs can serve as a delivery system that targets the tumor site and is therefore a promising therapeutic approach for PCa treatment.
基金theNationalNaturalScienceFoundationofChina (No .5 0 2 3 3 0 3 0 )theBasicResearchFoundationofTsinghuaUniversity (No .2 0 0 2 0 3 0 )
文摘Two novel amphiphilic poly(ester amine) dendrimers were synthesized and characterized by 1H NMR, 13 C NMR and IR spectra. Their properties of Langmuir film were investigated at the air/water interface. The relationship between the surface pressure and area isotherms of the dendrimers was found to be dependent on the nature of subphases. Interaction between HgCl 2 and the dendrimers was observed, indicating that the amphiphilic dendrimers could act as a sensor for Hg 2+ .
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.
基金Supported by the National Natural Science Foundation of China(No.50633010)
文摘The aromatic hyperbranched poly（ester amines）（AHPEAs） were successfully synthesized via the mild condensation of N-4-cyanobenzyl diethanolamine hydrogenchloride as an AB2 monomer in concentrated HCI. The polymerization was monitored by FTIR to suppose the reasonable reaction mechanism. The degree of branching was determined to be 0.55 by 1H NMR with an increased conversion of up to 96%. The glass transition temperature was measured by differential scanning calorimetry to range from -19 to 15℃ The molecular weights and polydispersities were investigated by gel permeation chromatography.
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 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).
文摘Hyperbranched poly(ester-amine) with terminal amine groups was synthesized by Michael addition reaction between trimethylolpropanetriacrylate (B 3 monomer) and pizine (A 2 monomer) under molar ratio of 6∶13 via a one-step procedure.It was further modified by stearyl chloride to form an amphiphilic hyperbranched polymer.The structures of these polymers were characterized by FT-IR,{}+1H-NMR,DSC and GPC analyses.Due to the existence of interior secondary amines,the modified polymer can be used as phase transferring agent to extract methylic orange from water layer to CHCl-3 layer.Both higher transferring capability and higher transferring rate were achieved at lower pH of the water phase.The extracted dye in the organic layer can be further released to the water layer under a basic condition.A possible mechanism for extracting dye by amphiphilic hyperbranched polymer was suggested.
