Reaction and characterization of crosslinking hyperbranched poly(amine-ester) with succine anhydride

Basing on hydroxyl terminated hyperbranched poly(amine-ester)s (HPAEs), the cross-linking reactions and preparation of ester-crosslinked HPAE films were investigated using succine anhydride (SA) as crosslink reagent. It was proved that the cross-linking reaction between HPAE and SA followed a two-step mechanism. This mechanism provides an efficient route to prepare HPAE/SA cross-linked films, in which, the precursor films were prepared by casting HPAE/SA solution at a lower temperature, and then curing the films at a higher temperature. By varying SA content, the solid HPAE/SA films with different cross-linking degrees were prepared successfully. The highest tensile strength of the cross-linked film could reach 59.60 MPa. With all water contact angle smaller than 74.3°, the crosslinked films demonstrated good hydrophilic properties. __________ Translated from Journal of East University of Science and Technology (Natural Science Edition), 2006, 32(10): 1,164–1,168 [译自: 华东理工大学学报 (自然科学版)]     

多壁碳纳米管接枝超支化聚(胺-酯)

采用混酸氧化,使碳纳米管表面产生羧基,再分别以接出法(grafting from)的方式在碳纳米管表面长出超支化大分子;以接入法(grafting to)的方式将由一步法合成的超支化聚(胺-酯)通过酯化反应接枝到碳纳米管表面。通过SEM、FTIR、TGA-DSC以及XRD等表征手段并结合酸碱滴定法测定修饰后碳纳米管表面的羟基密度,对功能化修饰的碳纳米管进行分析。结果表明,分别以grafting from和grafting to方式接枝超支化聚(胺-酯)后,碳纳米管的羟基密度分别为24.74 mmol/g和20.04 mmol/g,修饰后的碳纳米管分散性能明显提高,同时末端丰富的官能团为碳纳米管的进一步功能化修饰创造了条件。     

改性超支化聚（胺-酯）对亚硝酸根的吸附性能研究

以十八烷基三氯硅烷对超支化聚（胺-酯）进行改性,合成了改性的超支化聚（胺-酯）。改性的超支化聚（胺-酯）是一种既具有大量的端羟基且易从中水中分离出来的超支化聚（胺-酯）。将改性的超支化聚（胺-酯）用于吸附亚硝酸根离子,实验结果表明：改性的超支化聚合物对亚硝酸根离子的最大吸附量可达149．7mg／g,在酸性溶液中吸附量还将大大增加。     

Nanoparticles composed of PLGA and hyperbranched poly (amine-ester) as a drug carrier

A new hyperbranched poly (amine-ester)-poly (lactide-co-glycolide) (HPAE-co-PLGA) copolymer was synthesized by ring-opening polymerization of D, L-lactide, glycolide and a fourth generation branched poly (amine-ester) (HPAE-OHs4) with Sn(Oct)₂ as catalyst. The chemical structures of copolymers were determined by FT-IR, ¹H-NMR (¹³C NMR), TGA and their molecular weights were determined by gel permeation chromatography (GPC). Two methods, double emulsion (DE) and nanoprecipitation (NP), were employed to fabricate the polymeric nanoparticles. Isoniazid (INH) was loaded as a model antitubercular drug. Influence of the preparation conditions on the nanoparticles size, encapsulation efficiency and release profile in vitro was investigated. Their entrapment efficiency (EE) to INH could reach 96% at an available condition. In vitro release behavior of NPs showed a continuous release after a burst release. The results showed that the HPAE-co-PLGA copolymer nanoparticles have a promising potential in hydrophilic drug delivery system.     

Novel hyperbranched poly (amine-ester)-poly (lactide-co-glycolide) polymeric micelles as amphotericin B carriers

A series of amphiphilic hyperbranched poly (amine-ester)-poly (lactide-co-glycolide) (HPAE-co-PLGA) copolymers were synthesized by ring-opening polymerization of dl-lactide, glycolide and a fourth generation hyperbranched poly (amine-ester) (HPAE-OHs4) with Sn(Oct)₂ as catalyst. The chemical structure of copolymers was characterized by Fourier transform infrared (FT-IR), nuclear magnetic resonance (¹H-NMR, ¹³C-NMR), thermo gravimetric analysis apparatus (TGA), and different scanning calorimetry (DSC). Formation and characteristics of polymeric micelles of the amphiphilic copolymer were studied by environmental scanning electron microscopy (ESEM), fluorescence spectroscopy, and dynamic light scattering (DLS). In order to estimate the feasibility as novel drug carriers, a lipophilic model drug amphotericin B was incorporated into polymeric micelles and the drug release behavior was investigated. The micelle size and drug-loading content were found increased, and the drug-release rate decreased with the increase of molar ratio of dl-lactide/glycolide to HPAE.     

Upgrading of MUF adhesives for particleboard production using oligomers of hyperbranched poly(amine-ester)

Oligomeric precursors of poly(amine-ester) were synthesized by a two-step condensation reaction of succinic anhydride with diethanolamine under mild conditions. The oligomers formed were characterized at each synthesis step using matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry. This showed that after step (1), the condensation adduct of both reactants (206?Da) was the main product mixed to high proportion of unreacted diethanolamine (106?Da). After step (2), the adduct at 206?Da decreased substantially, while other compounds at 275, 292, and 375?Da started to increase along with the appearance of a new compound at 392?Da. This indicates that the reaction proceeds slowly under these conditions to give higher branched oligomers (HP). In addition, some cyclic compounds were also identified by the 188, 275, and 375?Da peaks. MALDI-TOF of the melamine–urea–formaldehyde (MUF) resin before and after reaction with the hyperbranched oligomers mix showed clear indication of the coreaction of simple melamine–formaldehyde oligomers with several of the hyperbranched oligomers previously identified. Addition of small proportions of a mixture of the formed HP oligomers to a MUF adhesive improved the internal bond (IB) strength, both dry and wet, of wood particleboards bonded with it. The results obtained indicate that the addition of these HP oligomers can improve the dry IB strength by 17–24% according to conditions of preparation and the wet IB strength by as much as 47% when compared to the control sample.     

The synthesis of functionalized carbon nanotubes by hyperbranched poly(amine-ester) with liquid-like behavior at room temperature

The solvent-free multi-walled carbon nanotubes (MWNTs) nanofluids are obtained through acid-base reaction and hydrogen bond roles with hyperbranched poly(amine-ester) (HPAE). MWNTs content is 16.8 wt%. The functionalized MWNTs exhibit liquid-like behavior in absence of solvent at room temperature. Correspondingly, the dense surface coverage is one modifying molecule per 30 carbon atoms on the surface of MWNTs. The functionalized MWNTs are soluble in good solvent of HPAE, but insoluble in non-solvent of HPAE. Their dispersibility, high thermal stability and ability to flow at room temperature make them attractive as lubricants, plasticizers and film-forming precursors.     

The synthesis of hyperbranched poly (amine-ester) and study on the properties of its UV-curing film

Firstly, the monomer of N, N-diethylol-3-amine methylpropionate was obtained via Michael addition of methyl acrylate and diethanolamine. Then the hyperbranched poly (amine-ester) (HBPE) was synthesized through pentaerythritol as core molecules and monomer as AB₂. HBPE was characterized by Fourier transform-infrared spectroscopy, hydrogen nuclear magnetic resonance (¹H-NMR) and elemental analysis. Methyl tetrahydrophthalic anhydride (MTHPA) is grafted to the hydroxyl groups of HBPE and then glycidyl methacrylate (GMA) is introduced to the structure of HBPE, which is obtained by the UV-curable hyperbranched prepolymer (HBPE-MTHPA-GMA). Ultraviolet-differential scanning calorimeter showed that the HBPE-MTHPA-GMA has high photocuring speed under photoinitiator. Furthermore, the films also show good impact strength, outstanding adhesive force and primary thermal stability.     

Synthesis and characterization of hyperbranched poly(silyl ester)s

Hyperbranched poly(silyl ester)s were synthesized via the A₂ + B₄ route by the polycondensation reaction. The solid poly(silyl ester) was obtained by the reaction of di‐tert‐butyl adipate and 1,3‐tetramethyl‐1,3‐bis‐β(methyl‐dicholorosilyl)ethyl disiloxane. The oligomers with tert‐butyl terminal groups were obtained via the A₂ + B₂ route by the reaction of 1,5‐dichloro‐1,1,5,5‐tetramethyl‐3,3‐diphenyl‐trisi1oxane with excess amount of di‐tert‐butyl adipate. The viscous fluid and soft solid poly(silyl ester)s were obtained by the reaction of the oligomers as big monomers with 1,3‐tetramethyl‐1,3‐bis‐β(methyl‐dicholorosilyl)ethyl disiloxane. The polymers were characterized by ¹H NMR, IR, and UV spectroscopies, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The ¹H NMR and IR analysis proved the existence of the branched structures in the polymers. The glass transition temperatures (T_g's) of the viscous fluid and soft solid polymers were below room temperature. The T_g of the solid poly(silyl ester) was not found below room temperature but a temperature for the transition in the liquid crystalline phase was found at 42°C. Thermal decomposition of the soft solid and solid poly(silyl ester)s started at about 130°C and for the others it started at about 200°C. The obtained hyperbranched polymers did not decompose completely at 700°C. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3430–3436, 2006     

Synthesis and characterization of hyperbranched aromatic poly(ester-imide)s

The synthesis and characterization of hyperbranched aromatic poly(ester-imide)s are described. A variety of AB₂ monomers, N-[3- or 4-bis(4-acetoxyphenyl)toluoyl]-4-carboxyl-phthalimide and N-{3- or 4-[1,1-bis(4-acetooxyphenyl)]ethylphenyl}-4-carboxy phthalimides were prepared starting from condensation of nitrobenzaldehydes or nitroacetophenones with phenol and used for synthesis of hyperbranched poly(ester-imide)s containing terminal acetyl groups by transesterification reaction. These hyperbranched poly(ester-imide)s were produced with weight-average molecular weight of up to 6.87 g/mol. Analysis of ¹H NMR and ¹³C NMR spectroscopy revealed the structure of the four hyperbranched poly(ester-imide)s. These hyperbranched poly(ester-imide)s exhibited excellent solubility in a variety of solvents such as N,N-dimethylacetamide, dimethyl sulfoxide, and tetrahydrofuran and showed glass-transition temperatures between 217 and 255 °C. The thermogravimetric analytic measurement revealed the decomposition temperature at 10% weight-loss temperature (T_d¹⁰) ranging from 365 to 416 °C in nitrogen.     

Preparation and characterization of a bioadhesive with poly (vinyl alcohol) crosslinking agent

Synthetic adhesives containing 3,4‐dihydroxy‐L‐phenylalanine and its derivatives have strong adhesion strength and good biocompatibility, which make them prime candidates for adhesives or bioadhesives applications. In this study, a new photocurable poly (vinyl alcohol) (UV‐PVA) derivative was prepared and used as crosslinking agent to further improve adhesion strength of dopamine methacrylamide (DMA) system. The structure of UV‐PVA was confirmed, and the degree of acryloyl group substitution (DS) was easily varied from 10 to 40% by varying the molar ratio of acryloyl chloride to ? OH of PVA. The effects of ultraviolet light intensity, content of DMA and DS values of PVA on the photopolymerization kinetics were studied, and the effects of DS value on the adhesive strength, swelling performance and cell attachment were also investigated. It was found that adhesive containing UV‐PVA with 40% DS value yielded the highest adhesive strength, a relatively low swelling ratio and good biocompatibility. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Synthesis and characterization of hyperbranched poly(ester-amine) by Michael addition polymerization

A series of tertiary amine-based hyperbranched poly(amine-ester)s have been synthesized by Michael addition polymerization of trifunctional monomer, TMEA and difunctional monomer, diacylates in chloroform, and the resultant polymers were subsequently treated with mercaptoethenol or 1-dodecanethiol for improving stability in storage. The caption efficiency of mercaptoethanol is much better than that of 1-dodecanthiol. Kinetic study reveals that the thiol group is consumed faster than the acrylate group when the polymerization with feed molar ratio of diacrylate/TMEA = 2/1 was carried out. At initial polymerization, monomer conversion increases fast, but the molecular weights increase slowly and sharp increase of the molecular weight occurs at the final polymerization. The hyperbranched polymers were well characterized by ¹H NMR spectra and TD-SEC, and DBs of the polymers obtained are between 0.6 and 0.82, as well as the molar ratios of diacrylate/TMEA in the hyperbranched polymers are between 1.60 and 1.82. The fluorescence efficiency and quantum yields of HypET20, HypHT24 and HypDT24 has the following sequence: HypET20 > HypHT24 > HypDT24.     

树枝状聚（胺-酯）的功能化及其荧光性能研究

以乙二胺(EDA)、三羟甲基丙烷三丙烯酸酯(TMPTA)和苯甲醛(BZA)为原料,合成了聚(胺-酯)-苯甲醛树枝状大分子(PAE-BZA),产率为60.82%,色谱纯度为65.27%。用IR、1HNMR和13CNMR表征了它的结构;并测定了PAE-BZA的荧光性能;考察了不同浓度PAE-BZA、不同溶剂及n(Sn2+)/n(PAE-BZA)对其荧光性能的影响。结果表明,丙酮为溶剂时,0.5 mmol/L PAE-BZA荧光强度最强;以丙酮、甲醇、DMSO、DMF和乙醇等为溶剂,PAE-BZA在乙醇中的荧光强度最强。随着n(Sn2+)/n(PAE-BZA)增加,PAE-BZA的荧光强度先减弱后增强,且Sn2+与PAE-BZA络合顺序是由外围的N原子逐步向内部的N原子络合。     

Synthesis and characterization of new hyperbranched poly(ether ketones) with various number of phenylene units

A new series of AB₂ type monomers with aromatic thio and various number of phenylene units were prepared. Three series of AB₂ type monomers, 4-thio-3′,5′-bis(4-fluorobenzal)biphenyl 1, 4-thio-3′′,5′′-bis(4-fluorobenzal)-p-terphenyl 2 and 4-thio-3′′′,5′′′-bis(4-fluorobenzal)-p-quarterphenyl 3 were synthesized in a stepwise manner starting from 3,5-bis(4-fluorobenzoyl)phenol 4 by repeating a series of conversions of the hydroxy group to the triflate, cross-coupling reaction of the triflate with (p-methoxythiophenyl)boronic acid, reduction of carbonyl groups followed by conversion of methylthio to thio group. Three kinds of hyperbranched poly(ether ketones) were prepared by the polymerization of the these three AB₂ type monomers. All compounds were characterized by elemental analysis, thermal analysis, ¹H and ¹³C NMR spectrometry.     

Synthesis and application of water‐soluble hyperbranched poly(ester)s from maleic anhydride and glycerol

A water‐soluble hyperbranched polyester with a considerable number of hydroxyl terminal groups was synthesized by reacting maleic anhydride and glycerol in the absence of a solvent. The synthesized intermediate product was converted to the hyperbranched polyester by condensation polymerization, and the water by‐product produced during the esterification reaction may be removed by vacuum distillation. In the synthesis process, the crosslinking reaction occurs readily if maleic anhydride is in excess. The result shows that the product synthesized by this one‐step method is insoluble in water at room temperature, whereas the product of a quasi one‐step method, in which pentaerythritol was added as a core molecule, has good water solubility when pentaerythritol and the raw material have a molar ratio of 1 : 100 or 1 : 150. The resulting hyperbranched polyester was purified by column chromatography and characterized by infrared spectrometry. The synthetic hyperbranched polyester was used at 0.5% as a crosslinking agent for acrylic ester to inform acrylic ester latex film; the water absorption of the film was decreased significantly, the viscosity was increased, and some mechanical properties were improved. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis and characterization of poly(N-vinyl pyrrolidone-alt-maleic anhydride): Conjugation with bovine serum albumin

Alternate N-vinyl pyrrolidone/maleic anhydride (NVPMA) copolymers were obtained by radical solution polymerization in dioxane with various MA contents in the monomer feed. The conversion of each monomer was monitored by proton nuclear magnetic resonance spectroscopy (¹H NMR), and the kinetics investigation showed that both monomers had identical polymerization rates if both monomers were present in the reaction mixture. The presence of excess NVP in the polymerization medium increased the kinetics of the polymerization and the molar masses of the resulting polymers. This increase was attributed to a cosolvent effect due to NVP, which is a better solvent for the polymer than dioxane. The hydrolysis rate constant of the polymers increased with pH, and NVPMA copolymers were more prone to hydrolysis (by a factor 10) than the methyl vinyl ether ones. Finally, the immobilization of bovin serum albumin (BSA) was investigated. A 25 mM phosphate buffer (pH 5.5) was the best medium to covalently bind 5 BSA molecules onto a 29 kDa NVPMA copolymer and 13 BSA molecules onto a 58 kDa sample, with grafting efficiencies > 90%. Noncovalent interactions with the hydrolyzed form of the polymer and BSA occured at pHs lower than the isoelectric point of BSA, and the resulting complexes were insoluble in water. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 3327–3337, 2001     

Photolytic crosslinking of poly(p-hydroxystyrene)

Light-induced crosslinking of poly(p-hydroxystyrene) (PPHS) is significantly enhanced by O₂. This was evidenced by molar mass (light scattering measurements) and by gel content determinations which were performed on various polymer samples before and after continuous irradiation at λ_inc = 254 nm. The following mechanism was elucidated with the aid of flash photolysis studies: Crosslinking in the absence or presence of O₂ is mainly due to the combination of phenoxyl type radicals. In the absence of O₂ the latter are exclusively formed by O? H bond cleavage of singlet excited phenolic groups. Triplet excited phenolic groups which are also formed do not deactivate via O? H bond cleavage but react very effectively with O₂. This reaction leads to the formation of HO and additional phenoxyl type radicals. All Commercial and most laboratory-prepared PPHS samples contain chemically bound impurities of quinoid nature. On the basis of results performed with model compounds of low molar mass, it is concluded that triplet excited quinoid groups react effectively with phenolic groups forming phenoxyl type radicals and that they are quite unreactive with respect to the abstraction of alphatic hydrogen atoms. Irradiation of PPHS at λ_inc = 254 nm causes the formation of quinoid groups which absorb strongly at this wavelength. Light absorption by these groups becomes a determining factor with respect to photochemical alteration in the course of further irradiation.     

Structure and properties of blends of poly(ethylene-co-vinyl alcohol) with poly(styrene-co-maleic anhydride)

In the present study, ethylene/vinyl alcohol (EVAL) copolymers with different hydroxyl contents were melt mixed with styrene/maleic anhydride (SMA) copolymers. These two copolymers have functional groups capable of reacting intermolecularly, giving stable products. All EVAL copolymers were prepared from the same ethylene/vinyl acetate (EVA) copolymer by controlled hydrolysis. The blends, prepared at constant temperature and rotation speed in the rheomixer, were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, and thermo-gravimetric analysis, as well as mechanical properties and extraction experiments. All the above measurements lead to the conclusion that a certain part of hydroxyls of EVAL have reacted with anhydride groups of SMA, leading to the formation of branched and cross-linked products. The effect of (1) the molar ratio of hydroxyl/maleic anhydride functional groups, (2) the overall concentration of the functional groups, and (3) the mixing time on the structure and properties of the blends are discussed. Emphasis is given on the influence of these factors on the tensile strength, the elongation at break, and impact strength of the products. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 983–999, 1997     

Synthesis,characterization and properties of poly(butylene succinate) modified with rosin maleopimaric acid anhydride

Huge hydrogenated phenanthrene ring segments were introduced into the main chain of poly(butylene succinate) by polymerization of succinic acid (SA), 1,4‐butanediol (BD) and rosin maleopimaric acid anhydride (RMA), which was obtained from maleic rosin. The chemical structure and composition of the copolyesters were determined with the aid of ¹H‐NMR, FTIR and elemental analysis. The thermal properties, crystallization behaviour and mechanical properties of the copolyester were then investigated using differential scanning calorimetry (DSC), wide‐angle X‐ray diffraction (WAXD), polarized light microscopy (PLM) and mechanical testing. With increasing content of hydrogenated phenanthrene ring segments, the melting temperature, the crystallization temperature and the relative degree of crystallinity decreased gradually, but the elongation at break and the notched impact strength of poly(butylene succinate) were enhanced without a significant deterioration of tensile strength. Copyright © 2006 Society of Chemical Industry     

超支化聚苯硫醚与线性聚苯硫醚的对比表征

以2,4-二氯苯硫酚为原料,采用一步法合成超支化聚苯硫醚。笔者运用红外光谱、拉曼光谱、荧光光谱、示差扫描量热分析、热重分析、广角X-射线衍射、溶解实验等分析手段,对超支化聚苯硫醚和线性聚苯硫醚的基本性能进行了对比。由于两者结构上的差异,使得两者表现出不同的特性。超支化聚苯硫醚具有三取代苯结构,具有很强的荧光效应、完全的不结晶、溶于有机溶剂、热降解温度低于线性聚苯硫醚约60℃等特性。广角X-射线衍射谱图也和结晶、无定型线性聚苯硫醚有很大不同。