Hyperbranched polymers(HBPs)have drawn great interest in the biomedical field on account of their special morphology,low viscosity,self-regulation,and facile preparation methods.Moreover,their large intramolecular cav...Hyperbranched polymers(HBPs)have drawn great interest in the biomedical field on account of their special morphology,low viscosity,self-regulation,and facile preparation methods.Moreover,their large intramolecular cavities,high biocompatibility,biodegradability,and targeting properties render them very suitable for anti-tumor drug delivery.Recently,exploiting the specific characteristics of the tumor microenvironment,a range of multifunctional HBPs responsive to the tumor microenvironment have emerged.By further introducing various types of drugs through physical embedding or chemical coupling,the resulting HBPs based delivery systems have played a crucial part in improving drug stability,increasing effective drug concentration,decreasing drug toxicity and side effects,and enhancing anti-tumor effect.Here,based on different types of tumor microenvironment stimulation signals such as pH,redox,temperature,etc.,we systematically review the preparation and response mechanism of HBPs,summarize the latest advances in drug delivery applications,and analyze the challenges and future research directions for such nanomaterials in biomedical clinical applications.展开更多
The novel hyperbranced polymers containing reductive groups were successfully prepared and characterized using redox/reversible addition fragmentation chain transfer （RAFT）/self-condensing vinyl polymerization （SCV...The novel hyperbranced polymers containing reductive groups were successfully prepared and characterized using redox/reversible addition fragmentation chain transfer （RAFT）/self-condensing vinyl polymerization （SCVP） method. Several redox initiating chemicals such as Cu（III）/--CONH2, Ce（IV）/--CONH2 and Ce（IV）/--OH were chosen to increase the free radical generating rate, and the chain transfer agent （CTA） was used to reduce the molecular chain propagating rate, in order to obtain polymers with high degree of branching. Detailed analyses based on the molecular weight, α value and the degree of branching of polymers （DB） obtained from 1H-NMR spectra and multi detector size exclusion chromatography （MDSEC） suggested the acquiring of hyperbranced polyacrylamides with Cu（III）/--CONH2 and Ce（IV）/--CONH2 as initiator in the presence of the CTA. Meanwhile, the as-prepared poly（N-hydroxymethyl acrylamide） （PNHAM） with higher DB value （0.48） proved that using Ce（IV）/--OH as the initiator could increase the free radical generating rate and diminish the gap between the propagating rate and the initiation rate during the reaction procedure. In addition, the effect of oxidant concentration on the Mark-Houwink index （α） value and the DB was also studied.展开更多
A series of novel hyperbranched polymers （HBPs） consisting ofa 2,7-subsituted 9-（heptadecan-9-yl）-9H-carbazole unit （A2＋A2＇） and a tetra-substituted green thermally activated delayed fluorescence （TADF） dye ...A series of novel hyperbranched polymers （HBPs） consisting ofa 2,7-subsituted 9-（heptadecan-9-yl）-9H-carbazole unit （A2＋A2＇） and a tetra-substituted green thermally activated delayed fluorescence （TADF） dye of 2,3,5,6-tetra（9H- carbazol-9-yl）-4-pyridinecarbonitrile （4CzCNPy, B4） have been synthesized via Suzuki cross-coupling reaction following an ＂Az＋A2＇＋B4＂ method. The polymers are named according to the polymerization ratio of 4CzCNPy monomer （5 mol%, 10 mol% and 15 mol% for HBPs of P2-P4 respectively, and 0 mol% for the control linear polymer P1）. Their thermal, optoelectronic and electrochemical properties have been characterized by a combination of techniques. All the polymers exhibit high thermal stability with the decomposition temperatures （Ta） above 400 ℃ and glass transition temperatures （Tg） up to 98℃. Unfortunately, the incorporation of TADF moiety into these HBP materials induced non-TADF characteristics. However, when the HBPs functionalized as the host for our previously developed 4CzCNPy TADF dopant in solution processed devices, maximum external quantum efficiency of 5.7% and current efficiency of 17.9 cd/A have been achieved in P3-based device, which is significantly higher than those of 1.5% and 4.2 cd/A for the linear polymer P1.展开更多
The analytical expressions of the various structural units and the average degree of branching for the hyperbranched polymers resulted from AB2 polycondensation with substitution effect were derived by the kinetic mec...The analytical expressions of the various structural units and the average degree of branching for the hyperbranched polymers resulted from AB2 polycondensation with substitution effect were derived by the kinetic mechanism. The reactivity difference between the 13 group in linear unit and that in terminal group has great effect on the molecular parameters of the products obtained. The concentration of terminal units has a maximum with the increase of the conversion of A groups （x）. The higher the reactivity ratio （r） of linear B group to branched one is, the later the maximum appears and the larger it is. The degree of branching of the hyperbranched polymers obtained is controllable by adjusting the parameters of r and x, which increases with increasing both x and r.展开更多
A series of hyperbranched poly(amine-ester)polyols were synthesized by the polycondensation of N,N-diethylol-3-amine-methylpropionate(prepared by Michael addition reaction of methyl acrylate with diethanolamine)as an ...A series of hyperbranched poly(amine-ester)polyols were synthesized by the polycondensation of N,N-diethylol-3-amine-methylpropionate(prepared by Michael addition reaction of methyl acrylate with diethanolamine)as an AB2-type monomer with trimethylol propane as the core moiety,proceeding in one-step procedure in the melt with p-toluenesulfonic acid as catalyst.The obtained monomer and polymers were characterized by FTIR and 1H-NMR spectroscopy.The solubility and surface activity in aqueous solution of the polymers were also examined.The gas permeability,water vapor permeability,and moisture absorption of microfiber synthetic leather treated by hyperbranched polymer were studied.The optimum conditions were that the dosage of dye and hyperbranched polymer was 5% and 10%,respectively.The water vapor permeability and moisture absorption of microfiber synthetic leather reached to 0.525 4 mg/(10 cm2·24 h)and 0.046 7 mg/(10 cm2·24 h).Compared with blank samples,they increased by 15% and 35%,respectively.However,the dosage of hyperbranched polymer has little influence on gas permeability of microfiber synthetic leather.SEM results show that the fiber of microfiber synthetic leather treated by hyperbranched polymer is incompact.展开更多
A Aeries of hydroxylic hyperbranched polymers were derived from 2,2-bis(methylol) propionic acid and tris(methylol) propane reacted with acrylic acid to various extents. The obtained acrylated hyperbranched polymers a...A Aeries of hydroxylic hyperbranched polymers were derived from 2,2-bis(methylol) propionic acid and tris(methylol) propane reacted with acrylic acid to various extents. The obtained acrylated hyperbranched polymers alone or with a monofunctional diluent, isobornylene acrylate(IBOA) were further cured by UV radiation. The cured films based on the modified polymers alone all demonstrated poor mechanical properties due to their high network densities and low moving ability of polymer chains. For the composite systems, the cured films demonstrated improved mechanical properties due to the low network densities and high chain moving ability. With more IBOA included in the systems, acrylate groups can react to a higher extent during the curing process.展开更多
By introducing semicrystalline moieties into hyperbranched molecular smictures three kinds of prepolymers of potential use as UV powder coatings were prepared and characterized.
Addressing the critical challenges of viscosity loss and barite sag in synthetic-based drilling fluids(SBDFs)under high-temperature,high-pressure(HTHP)conditions,this study innovatively developed a hyperbranched amide...Addressing the critical challenges of viscosity loss and barite sag in synthetic-based drilling fluids(SBDFs)under high-temperature,high-pressure(HTHP)conditions,this study innovatively developed a hyperbranched amide polymer(SS-1)through a unique stepwise polycondensation strategy.By integrating dynamic ionic crosslinking for temperature-responsive rheology and rigid aromatic moieties ensuring thermal stability beyond 260℃,SS-1 achieves a molecular-level breakthrough.Performance evaluations demonstrate that adding merely 2.0 wt% SS-1 significantly enhances key properties of 210℃-aged SBDFs:plastic viscosity rises to 45 mPa⋅s,electrical stability(emulsion voltage)reaches 1426 V,and the sag factor declines to 0.509,outperforming conventional sulfonated polyacrylamide(S-PAM,0.531)by 4.3%.Mechanistic investigations reveal a trifunctional synergistic anti-sag mechanism involving electrostatic adsorption onto barite surfaces,hyperbranched steric hindrance,and colloid-stabilizing network formation.SS-1 exhibits exceptional HTHP stabilization efficacy,substantially surpassing S-PAM,thereby providing an innovative molecular design strategy and scalable solution for next-generation high-performance drilling fluid stabilizers.展开更多
Functional hyperbranched polymers,as an important class of materials,are widely applied in diverse areas.Therefore,the development of simple and efficient reactions to prepare hyperbranched polymers is of great signif...Functional hyperbranched polymers,as an important class of materials,are widely applied in diverse areas.Therefore,the development of simple and efficient reactions to prepare hyperbranched polymers is of great significance.In this work,trialdehydes,diamines,and trimethylsilyl cyanide could easily undergo multicomponent polymerization under mild conditions,producing hyperbranched poly(α-aminonitrile)s with high molecular weights(M_(w) up to 4.87×10^(4))in good yields(up to 85%).The hyperbranched poly(α-aminonitrile)s have good solubility in commonly used organic solvents,high thermal stability as well as morphological stability.Furthermore,due to the numerous aldehyde groups in their branched chains,these hb-poly(α-aminonitrile)s can undergo one-pot,two-step,four-component post-polymerization with high efficiency.This work not only confirms the efficiency of our established catalyst-free multicomponent polymerization of aldehydes,amines and trimethylsilyl cyanide,but also provides a versatile and powerful platform for the preparation of functional hyperbranched polymeric materials.展开更多
A series of amphiphilic hyperbranched polymers(AHP-s,the“s”refers to the algebra of AHP)were synthesized by the reaction between hydroxyl-terminated hyperbranched polymers(HBP-s,the“s”refers to the algebra of HBP)...A series of amphiphilic hyperbranched polymers(AHP-s,the“s”refers to the algebra of AHP)were synthesized by the reaction between hydroxyl-terminated hyperbranched polymers(HBP-s,the“s”refers to the algebra of HBP)and palmitoyl chloride.FTIR,NMR and GPC were used to determine the structure of AHP-s,the results showed that AHP-s exhibits core-shell structure.The thermal properties of polymers were investigated by DSC and TGA.It was found that AHP-2,AHP-3 and AHP-4 display higher thermal stability than AHP-1(AHP-1,AHP-2,AHP-3 and AHP-4 represent the first,second,third and fourth generation AHP,respectively).Furthermore,the self-assembly performance of AHP-s in THF solvent was investigated by TEM and SEM.Finally,the encapsulation capacity of the AHP-s for methyl orange(MO)was explored at different concentrations of AHP-s and pH conditions.It was found that AHP-s is capable of accommodating hydrophilic vip MO.Moreover,the higher generation of AHP-s,the stronger encapsulation capacity obtained.And the encapsulation capacity closely associated with the pH of encapsulation system.展开更多
The research on the supramolecular hyperbranched polymers(SHPs) that combines the advantages of supramolecular polymer and hyperbranched architecture has attracted considerable interests in many applications. Here we ...The research on the supramolecular hyperbranched polymers(SHPs) that combines the advantages of supramolecular polymer and hyperbranched architecture has attracted considerable interests in many applications. Here we demonstrate a simple approach to prepare POSS-embedded supramolecular hyperbranched polymers(POSS-SHPs) with varied morphology and size by controlling monomer concentration and mixed solvents. The SHPs formations can further transfer into the core-shell structured micelles by addition of competitive vips based on the double supramolecular driving forces.展开更多
Dendronized hyperbranched polymer （DHP） is a new kind of polymer, which combines the advantages of dendrimers and hy- perbranched polymers. In this work, two dendronized hyperbranched polymers, DttPG0 and DHPG1, wer...Dendronized hyperbranched polymer （DHP） is a new kind of polymer, which combines the advantages of dendrimers and hy- perbranched polymers. In this work, two dendronized hyperbranched polymers, DttPG0 and DHPG1, were successfully pre- pared through the simple ＂A3＋B2＂ type Sonogashira coupling reaction. The nonlinear optical （NLO） effects of DHPG0 and DItPG1, characterized by the d33 values, were 183 and 220 pm V-1 respectively, higher than those of their analogues of den- dronized polymers and dendrimers, thanks to the special topological structure. Also, the obtained polymers displayed excellent solubility, good processability, and high thermal stability.展开更多
In this work, surface-relief-grating formation behavior was studied by using two hyperbranched azo polymers. The hyperbranched polymers containing pseudo-stilbene type azo chromophores throughout the hyperbranched str...In this work, surface-relief-grating formation behavior was studied by using two hyperbranched azo polymers. The hyperbranched polymers containing pseudo-stilbene type azo chromophores throughout the hyperbranched structure were synthesized by step-growth polycondensation of AB2 type monomers. The AB2 monomer, 4-（4＇-（bis（2-chloroethyl）amino）- phenylazo）benzoic acid （BAA）, was prepared through azo-coupling reaction between N,N＇-bis（2-chloroethyl）aniline and 4- aminobenzenic acid. The another AB2 monomer, 4-（4＇-（bis（2-chloroethyl）amino）phenylazo）-3-nitro-benzoic acid （BANA）, was prepared through azo-coupling reaction between N,N-bis（2-chloroethyl）aniline and 3-nitro-4-aminobenzenic acid. The hyperbranched polymers （PBAA and PBANA） were prepared through nucleophilic substitution reaction of BAA and BANA, respectively. The polymers synthesized were characterized by using spectroscopic methods and thermal analysis. The photoinduced dichroism and photo-induced surface-relief-grating （SRG） formation of the hyperbranched polymers were investigated upon irradiation with Ar＋ laser at 488 nm. PBAA shows typical photoinduced dichroism SRG formation behavior. On the contrary, PBANA does not show the photoresponsive properties. The results indicate that the nitro at the ortho position of azo group of PBANA shows the effect of inhibiting the photoinduced variations. The effect can be attributed to the blockage of the trans-cis isomerization of the azobenzene moieties by the steric hindrance.展开更多
The separation of aromatic/aliphatic hydrocarbon mixtures is crucial in the petrochemical industry.Pervaporation is regarded as a promising approach for the separation of aromatic compounds from alkanes. Developing me...The separation of aromatic/aliphatic hydrocarbon mixtures is crucial in the petrochemical industry.Pervaporation is regarded as a promising approach for the separation of aromatic compounds from alkanes. Developing membrane materials with efficient separation performance is still the main task since the membrane should provide chemical stability, high permeation flux, and selectivity. In this study, the hyperbranched polymer(HBP) was deposited on the outer surface of a polyvinylidene fluoride(PVDF)hollow-fiber ultrafiltration membrane by a facile dip-coating method. The dip-coating rate, HBP concentration, and thermal cross-linking temperature were regulated to optimize the membrane structure.The obtained HBP/PVDF hollow-fiber-composite membrane had a good separation performance for aromatic/aliphatic hydrocarbon mixtures. For the 50%/50%(mass) toluene/n-heptane mixture, the permeation flux of optimized composite membranes could reach 1766 g·m^(-2)·h^(-1), with a separation factor of 4.1 at 60℃. Therefore, the HBP/PVDF hollow-fiber-composite membrane has great application prospects in the pervaporation separation of aromatic/aliphatic hydrocarbon mixtures.展开更多
Hyperbranched aromatic polymers were prepared by Friedel-Crafts reaction with Lewis acid, AlCl3 and ZnCl2, as the catalysts. In this work, hyperbranched polybenzyl (PB) and poly(methylene)naphthalene (PN) were synthes...Hyperbranched aromatic polymers were prepared by Friedel-Crafts reaction with Lewis acid, AlCl3 and ZnCl2, as the catalysts. In this work, hyperbranched polybenzyl (PB) and poly(methylene)naphthalene (PN) were synthesized and characterized by H-1-NMR and GPC. In addition, their florescence properties were measured with steady-state florescence spectra in THF and ethylene dichloride. The quantum yields of polybenzyl and poly(methylene)naphthalene in ethylene dichloride are much larger than those in THE.展开更多
1 Results UV curing systems have been widely used in various industries such as coatings,printing inks,and photo-resists,because of their low volatile organic compound (VOC),excellent physical properties,and energy sa...1 Results UV curing systems have been widely used in various industries such as coatings,printing inks,and photo-resists,because of their low volatile organic compound (VOC),excellent physical properties,and energy saving.Recently,these systems have also been applied to electronics and information technology fields such as display,CD,DVD,optical-fiber,and optical-device. In these curing systems,(meth)acrylate oligomers are mainly used due to their high photochemical reactivity. Recently,dendritic polyme...展开更多
Polycyclotrimerization and polycoupling of acetylenic monomers respectively furnish hyperbranched polyarylenes and polyynes with high molecular weights （up to 1 × 10^6） in high yields （up to 99.9%）. The polym...Polycyclotrimerization and polycoupling of acetylenic monomers respectively furnish hyperbranched polyarylenes and polyynes with high molecular weights （up to 1 × 10^6） in high yields （up to 99.9%）. The polymers possess low intrinsic viscosities and high thermal stabilities, losing little of their weights when heated to 〉 400℃. Upon pyrolysis at 〉 800℃, the polymers graphitize with high char yields （up to 86%）. Hyperbranched polyarylenes efficiently emit deep-blue to blue-green lights with fluorescence quantum yields up to 98% and strongly attenuate intense laser pulses with optical power-limiting performances superior to that of C60, a well-known optical limiter. Poly（alkenephenylenes）, poly（aroylarylenes） and polyynes are readily cross-linkable by UV irradiation, serving as excellent photoresist materials for the generation of patterns with nanometer resolution. Thin films of hyperbranched polyynes exhibit very high refractive indexes （n up to 1.86）. The internal and terminal acetylene moieties of the polyynes readily form complexes with cobalt carbonyls, which can be transformed into soft ferromagnetic ceramics with high magnetic susceptibilities （Ms up to ca. 118 emu/g） and near-zero magnetic losses.展开更多
Recently, hyperbranched polymers(HBPs), which differ significantly in structure and properties from linear, cross-linked and branched analogs, have become increasingly important. HBP have a spatial unloaded core and a...Recently, hyperbranched polymers(HBPs), which differ significantly in structure and properties from linear, cross-linked and branched analogs, have become increasingly important. HBP have a spatial unloaded core and a shell of branched monomer units(dendrons), in which functional groups are predominantly located in the surface layer. The size of macromolecules ranges from 2 nm to 100 nm. Currently, there are a fairly large number of publications in the literature devoted to the modification of hyperbranched polyester polyols with various functional groups and the assessment of the potential for their use. However, there are no review articles on this topic in recent years. In this regard, it is relevant to generalize the latest achievements in the field of synthesis, properties and application of hyperbranched polyester polyols with terminal oxygen, nitrogen, silicon, sulfur and organophosphorus fragments. The advantage of hyperbranched polyester polyols of the Boltorn H series is their industrial availability, biodegradability, nanoscale, non-toxicity and high solubility in various polar solvents due to short monomer units, as well as the presence of reactive terminal hydroxyl groups. Functionalization of hyperbranched polyester polyols at hydroxyl groups is mainly carried out by addition of acid anhydrides, iso(thio)cyanates, alkenes, lactides, lactones, lactams, epoxy compounds or reactions with halogenated compounds(alkyl halides, acid chlorides). In some cases, for the functionalization of polyester polyols special linkers are used, such as acid chlorides of unsaturated or dicarboxylic acids, diisocyanates, etc., which provide covalent bonding of the hyperbranched polymer with the target functional group. The obtained derivatives of hyperbranched polyesters are widely used in such areas as biomedicine, pharmacy, paints and varnishes, they are also used as catalysts, membranes, multifunctional coatings, plasticizers and polymer stabilizers.展开更多
A series of new hyperbranched poly(aryleneethynylene)s are synthesized by the copolycyclotrimerizations oftetraynes(Ⅰand Ⅱ)with aliphatic monoynes(A-C)catalyzed by tantalum-,niobium-,and cobalt-based catalysts.All t...A series of new hyperbranched poly(aryleneethynylene)s are synthesized by the copolycyclotrimerizations oftetraynes(Ⅰand Ⅱ)with aliphatic monoynes(A-C)catalyzed by tantalum-,niobium-,and cobalt-based catalysts.All thereactions proceed smoothly and soluble polymers of high molecular weights(M_w up to 3.8×10~4)are obtained in high yields(up to 97%).展开更多
A novel acrylamide A2B2＊ （A = alkene, B＊ = alkyl chlorine） type inimer was obtained from commercially available 1,2-ethylenediamine, chloroacetyl chloride and acryloyl chloride. The as-prepared monomer can form wa...A novel acrylamide A2B2＊ （A = alkene, B＊ = alkyl chlorine） type inimer was obtained from commercially available 1,2-ethylenediamine, chloroacetyl chloride and acryloyl chloride. The as-prepared monomer can form water-soluble hyperbranched poly（N,N-ethylidene bis（N-2-chloroacetyl acrylamide））s （HPECA） through atom transfer radical polymerization/self-condensing vinyl polymerization method in the presence alkyl chlorine/CuCl/2,2-bipyridine activation system which can effectively suppress the gelation formation.1H-NMR spectra and dual detector size exclusion chromatography proved the hyperbranched structure indisputably, and the degree of branching was determined by the detailed analyses of 1H-NMR spectra. The trend of the degree of branching was in consistent with the result of Mark- Houwink exponent a. The experiment results suggested that the conversion was 67%, Mw = 13.2 x 104, Mark-Houwink a = 0.282 and the degree of branching = 64% when the reaction temperature was 120 ℃, reaction time = 168 h and N,N- ethylidene bis（N-2-chloroacetyl acrylamide）：Cu（I） = 50：0.62.展开更多
基金supported by the Overseas Study Program of China Scholarship Council(Grant No.:202202505006)the Excellent Youth Project of Education Department of Hunan Province of China(Project No.:23B0447)+2 种基金the Natural Science Foundation of Hunan Province of China(Grant No.:2021JJ30597)the Health Research Project of Hunan Provincial Health Commission,China(Grant No.:202113022002)the Hengyang Guided Science and Technology Project,China(Grant No.:2020jh042809).
文摘Hyperbranched polymers(HBPs)have drawn great interest in the biomedical field on account of their special morphology,low viscosity,self-regulation,and facile preparation methods.Moreover,their large intramolecular cavities,high biocompatibility,biodegradability,and targeting properties render them very suitable for anti-tumor drug delivery.Recently,exploiting the specific characteristics of the tumor microenvironment,a range of multifunctional HBPs responsive to the tumor microenvironment have emerged.By further introducing various types of drugs through physical embedding or chemical coupling,the resulting HBPs based delivery systems have played a crucial part in improving drug stability,increasing effective drug concentration,decreasing drug toxicity and side effects,and enhancing anti-tumor effect.Here,based on different types of tumor microenvironment stimulation signals such as pH,redox,temperature,etc.,we systematically review the preparation and response mechanism of HBPs,summarize the latest advances in drug delivery applications,and analyze the challenges and future research directions for such nanomaterials in biomedical clinical applications.
基金financially supported by the National Natural Science Foundation of China(Nos.20904008 and 21274037)College of Science and Technology Foundation of Hebei Education Department(2010015,B2010000214)
文摘The novel hyperbranced polymers containing reductive groups were successfully prepared and characterized using redox/reversible addition fragmentation chain transfer （RAFT）/self-condensing vinyl polymerization （SCVP） method. Several redox initiating chemicals such as Cu（III）/--CONH2, Ce（IV）/--CONH2 and Ce（IV）/--OH were chosen to increase the free radical generating rate, and the chain transfer agent （CTA） was used to reduce the molecular chain propagating rate, in order to obtain polymers with high degree of branching. Detailed analyses based on the molecular weight, α value and the degree of branching of polymers （DB） obtained from 1H-NMR spectra and multi detector size exclusion chromatography （MDSEC） suggested the acquiring of hyperbranced polyacrylamides with Cu（III）/--CONH2 and Ce（IV）/--CONH2 as initiator in the presence of the CTA. Meanwhile, the as-prepared poly（N-hydroxymethyl acrylamide） （PNHAM） with higher DB value （0.48） proved that using Ce（IV）/--OH as the initiator could increase the free radical generating rate and diminish the gap between the propagating rate and the initiation rate during the reaction procedure. In addition, the effect of oxidant concentration on the Mark-Houwink index （α） value and the DB was also studied.
基金financially supported by the National Natural Science Foundation of China(No.21304047)Natural Science Foundation of Jiangsu Province(No.BK2016042)Research Fund for the Doctoral Program of Higher Education(No.20133221120015)
文摘A series of novel hyperbranched polymers （HBPs） consisting ofa 2,7-subsituted 9-（heptadecan-9-yl）-9H-carbazole unit （A2＋A2＇） and a tetra-substituted green thermally activated delayed fluorescence （TADF） dye of 2,3,5,6-tetra（9H- carbazol-9-yl）-4-pyridinecarbonitrile （4CzCNPy, B4） have been synthesized via Suzuki cross-coupling reaction following an ＂Az＋A2＇＋B4＂ method. The polymers are named according to the polymerization ratio of 4CzCNPy monomer （5 mol%, 10 mol% and 15 mol% for HBPs of P2-P4 respectively, and 0 mol% for the control linear polymer P1）. Their thermal, optoelectronic and electrochemical properties have been characterized by a combination of techniques. All the polymers exhibit high thermal stability with the decomposition temperatures （Ta） above 400 ℃ and glass transition temperatures （Tg） up to 98℃. Unfortunately, the incorporation of TADF moiety into these HBP materials induced non-TADF characteristics. However, when the HBPs functionalized as the host for our previously developed 4CzCNPy TADF dopant in solution processed devices, maximum external quantum efficiency of 5.7% and current efficiency of 17.9 cd/A have been achieved in P3-based device, which is significantly higher than those of 1.5% and 4.2 cd/A for the linear polymer P1.
基金financially supported by the National Natural Science Foundation of China(Nos.20774038,21044003)the fund of the State Key Laboratory of Metal Matrix Composites
文摘The analytical expressions of the various structural units and the average degree of branching for the hyperbranched polymers resulted from AB2 polycondensation with substitution effect were derived by the kinetic mechanism. The reactivity difference between the 13 group in linear unit and that in terminal group has great effect on the molecular parameters of the products obtained. The concentration of terminal units has a maximum with the increase of the conversion of A groups （x）. The higher the reactivity ratio （r） of linear B group to branched one is, the later the maximum appears and the larger it is. The degree of branching of the hyperbranched polymers obtained is controllable by adjusting the parameters of r and x, which increases with increasing both x and r.
基金National High Technology Research and Development Program of China(863program)(No.200803Z309)Optional Item of Shaanxi University of Science and Technology,China(No.ZX08-06)National Natural Science Foundation of China(No.20876090)
文摘A series of hyperbranched poly(amine-ester)polyols were synthesized by the polycondensation of N,N-diethylol-3-amine-methylpropionate(prepared by Michael addition reaction of methyl acrylate with diethanolamine)as an AB2-type monomer with trimethylol propane as the core moiety,proceeding in one-step procedure in the melt with p-toluenesulfonic acid as catalyst.The obtained monomer and polymers were characterized by FTIR and 1H-NMR spectroscopy.The solubility and surface activity in aqueous solution of the polymers were also examined.The gas permeability,water vapor permeability,and moisture absorption of microfiber synthetic leather treated by hyperbranched polymer were studied.The optimum conditions were that the dosage of dye and hyperbranched polymer was 5% and 10%,respectively.The water vapor permeability and moisture absorption of microfiber synthetic leather reached to 0.525 4 mg/(10 cm2·24 h)and 0.046 7 mg/(10 cm2·24 h).Compared with blank samples,they increased by 15% and 35%,respectively.However,the dosage of hyperbranched polymer has little influence on gas permeability of microfiber synthetic leather.SEM results show that the fiber of microfiber synthetic leather treated by hyperbranched polymer is incompact.
基金Supported by the National Natural Science Foundation of China(No.2 0 2 0 4 0 0 5 ,5 0 2 330 30 ) and Basic Research Fund ofTsinghua University(No.JC2 0 0 2 0 30 )
文摘A Aeries of hydroxylic hyperbranched polymers were derived from 2,2-bis(methylol) propionic acid and tris(methylol) propane reacted with acrylic acid to various extents. The obtained acrylated hyperbranched polymers alone or with a monofunctional diluent, isobornylene acrylate(IBOA) were further cured by UV radiation. The cured films based on the modified polymers alone all demonstrated poor mechanical properties due to their high network densities and low moving ability of polymer chains. For the composite systems, the cured films demonstrated improved mechanical properties due to the low network densities and high chain moving ability. With more IBOA included in the systems, acrylate groups can react to a higher extent during the curing process.
基金This work was supported by the National Natural Science Foundation of China (No. 59673026).
文摘By introducing semicrystalline moieties into hyperbranched molecular smictures three kinds of prepolymers of potential use as UV powder coatings were prepared and characterized.
基金financially supported by the Scientific Research Start-up Fund Project of Anhui Polytechnic University for Introducing Talents(No.2022YQQ081)Natural Science Research Project of Anhui Educational Committee(No.2024AH050133)the National Natural Science Foundation of China(No.22001078).
文摘Functional hyperbranched polymers,as an important class of materials,are widely applied in diverse areas.Therefore,the development of simple and efficient reactions to prepare hyperbranched polymers is of great significance.In this work,trialdehydes,diamines,and trimethylsilyl cyanide could easily undergo multicomponent polymerization under mild conditions,producing hyperbranched poly(α-aminonitrile)s with high molecular weights(M_(w) up to 4.87×10^(4))in good yields(up to 85%).The hyperbranched poly(α-aminonitrile)s have good solubility in commonly used organic solvents,high thermal stability as well as morphological stability.Furthermore,due to the numerous aldehyde groups in their branched chains,these hb-poly(α-aminonitrile)s can undergo one-pot,two-step,four-component post-polymerization with high efficiency.This work not only confirms the efficiency of our established catalyst-free multicomponent polymerization of aldehydes,amines and trimethylsilyl cyanide,but also provides a versatile and powerful platform for the preparation of functional hyperbranched polymeric materials.
基金funded by National Science and Technology Major Project(No.2017YFB0308500)Shaanxi Science and Technology Project(No.2018JM5164)+1 种基金Science and Technology Plan Project of Xi'an Weiyang District(No.201907)the Youth Innovation Team of Shaanxi Universities.
文摘A series of amphiphilic hyperbranched polymers(AHP-s,the“s”refers to the algebra of AHP)were synthesized by the reaction between hydroxyl-terminated hyperbranched polymers(HBP-s,the“s”refers to the algebra of HBP)and palmitoyl chloride.FTIR,NMR and GPC were used to determine the structure of AHP-s,the results showed that AHP-s exhibits core-shell structure.The thermal properties of polymers were investigated by DSC and TGA.It was found that AHP-2,AHP-3 and AHP-4 display higher thermal stability than AHP-1(AHP-1,AHP-2,AHP-3 and AHP-4 represent the first,second,third and fourth generation AHP,respectively).Furthermore,the self-assembly performance of AHP-s in THF solvent was investigated by TEM and SEM.Finally,the encapsulation capacity of the AHP-s for methyl orange(MO)was explored at different concentrations of AHP-s and pH conditions.It was found that AHP-s is capable of accommodating hydrophilic vip MO.Moreover,the higher generation of AHP-s,the stronger encapsulation capacity obtained.And the encapsulation capacity closely associated with the pH of encapsulation system.
基金supported by the National Natural Science Foundation of China(21504096,21674120,21474115)Ministry of Science and Technology of China(2014CB932200)“Young Thousand Talents”Program
文摘The research on the supramolecular hyperbranched polymers(SHPs) that combines the advantages of supramolecular polymer and hyperbranched architecture has attracted considerable interests in many applications. Here we demonstrate a simple approach to prepare POSS-embedded supramolecular hyperbranched polymers(POSS-SHPs) with varied morphology and size by controlling monomer concentration and mixed solvents. The SHPs formations can further transfer into the core-shell structured micelles by addition of competitive vips based on the double supramolecular driving forces.
基金supported by the National Natural Science Foundation of China(21325416)
文摘Dendronized hyperbranched polymer （DHP） is a new kind of polymer, which combines the advantages of dendrimers and hy- perbranched polymers. In this work, two dendronized hyperbranched polymers, DttPG0 and DHPG1, were successfully pre- pared through the simple ＂A3＋B2＂ type Sonogashira coupling reaction. The nonlinear optical （NLO） effects of DHPG0 and DItPG1, characterized by the d33 values, were 183 and 220 pm V-1 respectively, higher than those of their analogues of den- dronized polymers and dendrimers, thanks to the special topological structure. Also, the obtained polymers displayed excellent solubility, good processability, and high thermal stability.
文摘In this work, surface-relief-grating formation behavior was studied by using two hyperbranched azo polymers. The hyperbranched polymers containing pseudo-stilbene type azo chromophores throughout the hyperbranched structure were synthesized by step-growth polycondensation of AB2 type monomers. The AB2 monomer, 4-（4＇-（bis（2-chloroethyl）amino）- phenylazo）benzoic acid （BAA）, was prepared through azo-coupling reaction between N,N＇-bis（2-chloroethyl）aniline and 4- aminobenzenic acid. The another AB2 monomer, 4-（4＇-（bis（2-chloroethyl）amino）phenylazo）-3-nitro-benzoic acid （BANA）, was prepared through azo-coupling reaction between N,N-bis（2-chloroethyl）aniline and 3-nitro-4-aminobenzenic acid. The hyperbranched polymers （PBAA and PBANA） were prepared through nucleophilic substitution reaction of BAA and BANA, respectively. The polymers synthesized were characterized by using spectroscopic methods and thermal analysis. The photoinduced dichroism and photo-induced surface-relief-grating （SRG） formation of the hyperbranched polymers were investigated upon irradiation with Ar＋ laser at 488 nm. PBAA shows typical photoinduced dichroism SRG formation behavior. On the contrary, PBANA does not show the photoresponsive properties. The results indicate that the nitro at the ortho position of azo group of PBANA shows the effect of inhibiting the photoinduced variations. The effect can be attributed to the blockage of the trans-cis isomerization of the azobenzene moieties by the steric hindrance.
基金financially supported by the National Natural Science Foundation of China (22178008, 22125801)Petrochina (2022DJ6004)。
文摘The separation of aromatic/aliphatic hydrocarbon mixtures is crucial in the petrochemical industry.Pervaporation is regarded as a promising approach for the separation of aromatic compounds from alkanes. Developing membrane materials with efficient separation performance is still the main task since the membrane should provide chemical stability, high permeation flux, and selectivity. In this study, the hyperbranched polymer(HBP) was deposited on the outer surface of a polyvinylidene fluoride(PVDF)hollow-fiber ultrafiltration membrane by a facile dip-coating method. The dip-coating rate, HBP concentration, and thermal cross-linking temperature were regulated to optimize the membrane structure.The obtained HBP/PVDF hollow-fiber-composite membrane had a good separation performance for aromatic/aliphatic hydrocarbon mixtures. For the 50%/50%(mass) toluene/n-heptane mixture, the permeation flux of optimized composite membranes could reach 1766 g·m^(-2)·h^(-1), with a separation factor of 4.1 at 60℃. Therefore, the HBP/PVDF hollow-fiber-composite membrane has great application prospects in the pervaporation separation of aromatic/aliphatic hydrocarbon mixtures.
基金Supported by the National Natural Science Foundation of China (Contract Grant No. 29604009)
文摘Hyperbranched aromatic polymers were prepared by Friedel-Crafts reaction with Lewis acid, AlCl3 and ZnCl2, as the catalysts. In this work, hyperbranched polybenzyl (PB) and poly(methylene)naphthalene (PN) were synthesized and characterized by H-1-NMR and GPC. In addition, their florescence properties were measured with steady-state florescence spectra in THF and ethylene dichloride. The quantum yields of polybenzyl and poly(methylene)naphthalene in ethylene dichloride are much larger than those in THE.
文摘1 Results UV curing systems have been widely used in various industries such as coatings,printing inks,and photo-resists,because of their low volatile organic compound (VOC),excellent physical properties,and energy saving.Recently,these systems have also been applied to electronics and information technology fields such as display,CD,DVD,optical-fiber,and optical-device. In these curing systems,(meth)acrylate oligomers are mainly used due to their high photochemical reactivity. Recently,dendritic polyme...
基金This work was partially supported by the Hong Kong Research Grants Council,the University Grants Committee of Hong Kong,and the National Natural Science Foundation of China.
文摘Polycyclotrimerization and polycoupling of acetylenic monomers respectively furnish hyperbranched polyarylenes and polyynes with high molecular weights （up to 1 × 10^6） in high yields （up to 99.9%）. The polymers possess low intrinsic viscosities and high thermal stabilities, losing little of their weights when heated to 〉 400℃. Upon pyrolysis at 〉 800℃, the polymers graphitize with high char yields （up to 86%）. Hyperbranched polyarylenes efficiently emit deep-blue to blue-green lights with fluorescence quantum yields up to 98% and strongly attenuate intense laser pulses with optical power-limiting performances superior to that of C60, a well-known optical limiter. Poly（alkenephenylenes）, poly（aroylarylenes） and polyynes are readily cross-linkable by UV irradiation, serving as excellent photoresist materials for the generation of patterns with nanometer resolution. Thin films of hyperbranched polyynes exhibit very high refractive indexes （n up to 1.86）. The internal and terminal acetylene moieties of the polyynes readily form complexes with cobalt carbonyls, which can be transformed into soft ferromagnetic ceramics with high magnetic susceptibilities （Ms up to ca. 118 emu/g） and near-zero magnetic losses.
文摘Recently, hyperbranched polymers(HBPs), which differ significantly in structure and properties from linear, cross-linked and branched analogs, have become increasingly important. HBP have a spatial unloaded core and a shell of branched monomer units(dendrons), in which functional groups are predominantly located in the surface layer. The size of macromolecules ranges from 2 nm to 100 nm. Currently, there are a fairly large number of publications in the literature devoted to the modification of hyperbranched polyester polyols with various functional groups and the assessment of the potential for their use. However, there are no review articles on this topic in recent years. In this regard, it is relevant to generalize the latest achievements in the field of synthesis, properties and application of hyperbranched polyester polyols with terminal oxygen, nitrogen, silicon, sulfur and organophosphorus fragments. The advantage of hyperbranched polyester polyols of the Boltorn H series is their industrial availability, biodegradability, nanoscale, non-toxicity and high solubility in various polar solvents due to short monomer units, as well as the presence of reactive terminal hydroxyl groups. Functionalization of hyperbranched polyester polyols at hydroxyl groups is mainly carried out by addition of acid anhydrides, iso(thio)cyanates, alkenes, lactides, lactones, lactams, epoxy compounds or reactions with halogenated compounds(alkyl halides, acid chlorides). In some cases, for the functionalization of polyester polyols special linkers are used, such as acid chlorides of unsaturated or dicarboxylic acids, diisocyanates, etc., which provide covalent bonding of the hyperbranched polymer with the target functional group. The obtained derivatives of hyperbranched polyesters are widely used in such areas as biomedicine, pharmacy, paints and varnishes, they are also used as catalysts, membranes, multifunctional coatings, plasticizers and polymer stabilizers.
基金This project was supported by the Research Grants Council of Hong Kong(Nos.603304,604903HKUST6085/02P).
文摘A series of new hyperbranched poly(aryleneethynylene)s are synthesized by the copolycyclotrimerizations oftetraynes(Ⅰand Ⅱ)with aliphatic monoynes(A-C)catalyzed by tantalum-,niobium-,and cobalt-based catalysts.All thereactions proceed smoothly and soluble polymers of high molecular weights(M_w up to 3.8×10~4)are obtained in high yields(up to 97%).
基金financially supported by National Natural Science Foundation of China (Nos. 20904008 and 21274037)Science and Technology Foundation of Hebei Education Department (grant Nos. 2010015 and 2009307)
文摘A novel acrylamide A2B2＊ （A = alkene, B＊ = alkyl chlorine） type inimer was obtained from commercially available 1,2-ethylenediamine, chloroacetyl chloride and acryloyl chloride. The as-prepared monomer can form water-soluble hyperbranched poly（N,N-ethylidene bis（N-2-chloroacetyl acrylamide））s （HPECA） through atom transfer radical polymerization/self-condensing vinyl polymerization method in the presence alkyl chlorine/CuCl/2,2-bipyridine activation system which can effectively suppress the gelation formation.1H-NMR spectra and dual detector size exclusion chromatography proved the hyperbranched structure indisputably, and the degree of branching was determined by the detailed analyses of 1H-NMR spectra. The trend of the degree of branching was in consistent with the result of Mark- Houwink exponent a. The experiment results suggested that the conversion was 67%, Mw = 13.2 x 104, Mark-Houwink a = 0.282 and the degree of branching = 64% when the reaction temperature was 120 ℃, reaction time = 168 h and N,N- ethylidene bis（N-2-chloroacetyl acrylamide）：Cu（I） = 50：0.62.
