Hyperbranched Polyester Research Articles

Dielectric properties of nanocomposites based on epoxy resin and HBP/plasma modified nanosilica

To enhance the bond strength of the nanosized silica/epoxy interface and modify the dielectric properties of nanocomposites, a plasma-assisted surface modification method is proposed for inorganic nanofillers. A gas–liquid two-phase dielectric barrier discharge at room temperature was initially used to graft the terminal carboxyl hyperbranched polyester onto the nanosilica surface. Then, epoxy resin composites filled with 1–7 wt. % nanosilica were prepared. The effects of the plasma-treated nanosilica on the dielectric properties of the epoxy resins were analyzed. The experimental results demonstrated that a 2 nm-thick film of hyperbranched polyester (HBP) was successfully deposited onto the nanosilica surface via the HBP/plasma treatment. Compared with the pristine epoxy resins at room temperature, the permittivity constant of the proposed nanocomposites decreased from 4.2 to 3.3 and their AC breakdown strength increased by 38%. Moreover, the dielectric loss factor and DC conductivity decreased by 40.7% and 48.4%, respectively. Additionally, deep traps of 0.99–1.53 eV were observed in the nanocomposites. It can be concluded that HBP/plasma processing creates strong chemical bonds and compact nanofiller/polymer interfacial regions. In addition, HBP/plasma processing modified the dielectric properties of the nanocomposites. The results of this study indicate that HBP/plasma treatment is an effective method for the surface modification of inorganic nanofillers and for the modification of the dielectric properties of polymer nanocomposites.

Synthesis of New Hyperbranched Dendrimers with Terminal Cationic Groups Based on Boltorn H20 Polyester Polyol

Terminal polychlorides of hyperbranched polyester polyol Boltorn H20 were synthesized. Subsequent treatment of the resultant polychlorides with absolute pyridine or triphenylphosphine led to the formation of products of varying degrees of functionalization, containing pyridinium or triphenylphosphonium moieties in terminal positions.

Effect of generation number on properties of fluoroalkyl‐terminated hyperbranched polyurethane latexs and its films

AbstractThe 1–3 generations of hyperbranched polyesters (HBPE‐1/2/3) were synthesized from trimethylolpropane (TMP) and 2,2‐dimethylol propionic acid (DMPA) by “quasi‐one‐step method.” Then, isophorone diisocyanate (IPDI), polybutylene adipate (CMA‐1044), DMPA and 1,4‐butanediol (BDO) were utilized to prepare the urethane prepolymer (PU), which was reacted with HBPE to synthesize hyperbranched polyurethanes (HBPU). Finally, 1–3 generations of fluoroalkyl‐end‐capped hyperbranched polyurethanes (FHBPU) latexes were obtained by the reaction of perfluorohexyl ethanol (S104) and HBPU as well as the self‐emulsification process. Structure of the products, the properties of different FHBPU emulsions and its films were investigated by FTIR, 1H NMR, TEM, DLS, TGA, XPS, XRD, SEM, AFM and static contact angle measuring instrument. Results showed that the particle size of FHBPU latexes increased gradually with the increase of generation number. SEM and XRD results verified that an amount of the crystal particles was increased with the increase of generation number. XPS and AFM demonstrated that degree of microphase separation and film roughness was increased with the increase of branching degree. Static water contact angles could attain 95.9°, 100.3°, and 107.0°, respectively on the 1–3 generations of FHBPU films, compared to that on PU (75.1°).

Facile and solvent-free synthesis of a novel bio-based hyperbranched polyester with excellent low-temperature flexibility and thermal stability

In this work, a novel biobased hyperbranched polyester (HBPE) with excellent low-temperature flexibility (low Tg) and thermal stability, was prepared from the self-polycondensation of AB2 monomer based on methyl ricinoleate (MR), a commercially available derivative from castor oil. The AB2 monomer was facilely synthesized by UV-initiated thiol-ene addition between MR and 2-mercaptoethanol in the absence of solvents. The reaction parameters were systematically optimized, and the highest yield up to 98 % was achieved with almost complete conversion of double bond within 2 h. A series of HBPEs were then obtained via bulk polymerization of the AB2 monomer under different conditions. Among the four transesterification catalysts investigated, Ti(OBu)4 was demonstrated to be the most efficient one due to the higher polymerization efficiency and molecular weight (Mn = 13,000∼17,000 g/mol) of as-obtained HBPEs. And the degree of branching (DB) was estimated to be in the range of 0.30∼0.42. Notably, the HBPEs with dangling chains exhibited a low glass transition temperature (Tg) of ―42.8∼―59.2 °C, indicative of excellent low-temperature flexibility. TGA results indicated that the onset thermal degradation temperature under nitrogen exceeded 310 °C for all the HBPEs. In comparison to the polyrincinoleate as a linear polyester analogue, the HBPE behaved like Newtonian fluid behaviors with lower complex viscosities.

Study on low dielectric laminate modified by hyperbranched polyester of caprylic acid and hexanoic acid co-blocking

There are higher requirements for various properties of copper-clad laminates under high-frequency conditions with the rapid development of information transmission. In the present study, a new kind of laminate is prepared by adding hyperbranched polyester (HBP) which is co-blocked by Caprylic acid and Hexanoic acid, applying to the high-frequency CCL. The hyperbranched structure of HBP was characterized by NMR and FT-IR. Based on dielectric property test, it could be found that HBP could reduce the dielectric constant (e) and the dielectric loss (tgδ) of laminate, the dielectric constant of laminate was 4.29 and the dielectric loss was 0.0037 at the frequency of 107 Hz. The method to lower the e is via increasing the content of free volume or reducing the content of polarizable functional groups in the system. Also the insulation test and the mechanical test showed the great properties of the laminate and the results of the flame retardant, moisture absorption and peel strength meet the application requirements of high-frequency CCL.

Ionization and Complexing Properties of Hyperbranched Polyester Poly[3-(2-aminoethyl)amino)]propionate

Syntheses of a polydentate ligand based on the second-generation hyperbranched polyester containing 3-(2-aminoethyl)amino]propionate groups and its metal complex with copper(II) ions have been elaborated. In view of the IR, electronic absorption, and EPR spectroscopy data, it has been suggested that the coordination sites in the metal-polymer complex are paramagnetic sites with the CuN4Solv2 or CuN2O2Solv2 composition (Solv = H2O, DMSO).

Toughness modification of cationic UV-cured cycloaliphatic epoxy resin by hydroxyl polymers with different structures

In this work, cationic UV-curable epoxy-expansive matrix composites based on cycloaliphatic epoxy resin (CE) were prepared using trarysulfonium hexafluorophosphate salt as photoinitiator, and hyperbranched polyester terminated with 6 hydroxy groups (H2004) or linear hydroxy-ended polytetramethylene ether glycol (PTMG) as toughness modifiers. Effects of H2004 and PTMG on the UV-curing kinetics, mechanical and thermal properties were systematically compared. An acceleration phenomenon was observed by real-time FTIR characterisation during the UV-curing of CE/H2004, which may be attributed to the hydroxy group participation of H2004 based on an activated monomer mechanism. However, the epoxy group conversion in the CE/PTMG composite decreased during UV irradiation owing to the random coil morphology of PTMG. Thermal-mechanical properties of the CE/H2004 composite were investigated by dynamic mechanical thermal analysis, which revealed that the glass transition temperature (Tg) decreased slightly as the H2004 dosage increased, in contrast to the Tg of the CE/PTMG composite, which increased as the PTMG content rose. Compared with CE, the thermal stability of CE/H2004 and CE/PTMG was less, but toughness was improved dramatically by increasing the content of H2004 or PTMG. At concentrations of H2004 and PTMG of 20% and 30%, respectively, the impact strength was improved from 1.14 J/cm2 for CE to 4.62 J/cm2 for CE/H2004 and 10.44 J/cm2 for CE/PTMG. This was further elucidated by fracture surface analysis with a scanning electron microscope.

UV-curable hyperbranched polyester acrylate encapsulation of phthalocyanine pigments for high performance synthetic fabrics printing

UV-curable hyperbranched polyester acrylate is formulated for encapsulation of phthalocyanine pigments using liquid-phase separation method. The encapsulated pigments were used as a UV-curable binder incorporated the pigment colours to eliminate the solid content, slow dry rate and hardness of conventional UV curable systems. Thermal gravimetric analysis (TGA), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS) and X-ray diffraction pattern (XRD) were examined in details. The characterization demonstrated the successful encapsulation of phthalocyanine pigments via UV-curable hyperbranched polyester acrylate. Thermal gravity analysis indicates that the encapsulated pigment films have better thermal stability than the pure pigments. The roughness and colour fastness to rubbing, washing, and light of the printed fabrics by encapsulated pigment, were compared to the same fabrics printed by conventional pigment printing using the UV curable formulation system with the linear counterpart of polyester acrylate as well as the conventional UV curable binder. The results showed that the printed samples with encapsulated pigment displayed the highest colour strength compared with the conventional printed samples. Additionally, the UV-curable hyperbranched polyester acrylate can be cured by short exposure to UV light and eliminate the surface roughness effect of UV curable system, decreased the solid content which increased the durability properties, rubbing and washing of printed fabrics.

Structure and Properties of PSf Hollow Fiber Membranes with Different Molecular Weight Hyperbranched Polyester Using Pentaerythritol as Core.

A homologous series of hyperbranched polyesters (HBPEs) was successfully synthesized via an esterification reaction of 2,2-bis(methylol)propionic acid (bis-MPA) with pentaerythritol. The molecular weights of the HBPEs were 2160, 2660, 4150 and 5840 g/mol, respectively. These HBPEs were used as additives to prepare polysulfone (PSf) hollow fiber membranes via non-solvent induced phase separation. The characteristic behaviors of the casting solution were investigated, as well as the morphologies, hydrophilicity and mechanical properties of the PSf membranes. The results showed that the initial viscosities of the casting solutions were increased, and the shear-thinning phenomenon became increasingly obvious. The demixing rate first increased and then decreased when increasing the HBPE molecular weight, and the turning point was 2660 g/mol. The PSf hollow fiber membranes with different molecular weights of HBPEs had a co-existing morphology of double finger-like and sponge-like structures. The starting pure water contact angle decreased obviously, and the mechanical properties improved.

Interaction of Poly(benzoyl thiocarbamate)-Modified Hyperbranched Polyester with Co(II) and Cu(II) Nitrates

The interaction of Co(NO3)2 and Cu(NO3)2 with hyperbranched polyester containing 7 terminal benzoyl thiocarbamate groups has been studied by IR-Fourier and electron absorption spectroscopy. А new polynuclear complexes of Co(II) and Cu(II) with poly(benzoyl thiocarbamate)-modified hyperbranched polyester have been synthesized. It has been found that the oxygen and sulfur atoms of the peripheral benzoyl thiocarbamate fragments of the macroligand are involved in coordination with metal ions, the metal to ligand ratio being 7 : 1.

Amphiphilic hyperbranched polyester coated rod mesoporous silica nanoparticles for pH-responsive doxorubicin delivery.

Rod-like mesoporous silica nanoparticles with pH-responsive amphiphilic hyperbranched polyester shells were prepared for doxorubicin (DOX) delivery. First, rod-shaped mesoporous silica nanoparticles (MSNs) were obtained, then hydrophobic hyperbranched polyester Boltorn H40 (H40) was grafted on their surface. The H40 coated MSNs were next treated with amine-functionalized polyethylene glycol (PEG) to achieve the hydrophilic and pH-responsive material denoted as PEG-H40-MSNs. The experimental results showed that PEG-H40-MSNs were successfully synthesized. BET analysis showed that rod MSNs exhibits a type IV standard isotherm. TEM revealed that the thin gray polymer layer was formed around the SBA-15 particle with a diameter of around 150nm. DOX was effectively loaded, which can be released according to the ambient pH inside the cell as follow: at pH7.4, only 9.7% of the DOX was released after 48h; as the pH decreased to 5.5, the cumulative release reached to 49% at the same time. PEG-H40-MSNs showed less than 1.6% of hemolytic activity and a slight effect on the liver and kidney of treated mice were observed at a high disposal dosage implying negligible toxicities were caused by PEG-H40-MSNs in both in vitro hemolysis analysis and in vivo biochemical in mice. However, the in vitro cytotoxicity evaluation of the DOX-PEG-H40-MSNs showed that the cell cytotoxicity of both pure DOX and DOX-loaded PEG-H40-MSNs generally enhanced by increasing the concentration of DOX. Graphical abstract Schematic of cellular uptake and DOX release of PEG-H40-MSNs nanoparticle.

Aromatic Hyperbranched Polyester/RTM6 Epoxy Resin for EXTREME Dynamic Loading Aeronautical Applications.

The effects of the addition of an aromatic hyperbranched polyester (AHBP) on thermal, mechanical, and fracture toughness properties of a thermosetting resin system were investigated. AHBP filler, synthesized by using a bulk poly-condensation reaction, reveals a glassy state at room temperature. Indeed, according to differential scanning calorimetry measurements, the glass transition temperature (Tg) of AHBP is 95 °C. Three different adduct weight percentages were employed to manufacture the AHBP/epoxy samples, respectively, 0.1, 1, and 5 wt%. Dynamical Mechanical Analysis tests revealed that the addition of AHBP induces a negligible variation in terms of conservative modulus, whereas a slight Tg reduction of about 4 °C was observed at 5 wt% of filler content. Fracture toughness results showed an improvement of both critical stress intensity factor (+18%) and critical strain energy release rate (+83%) by adding 5 wt% of AHBP compared to the neat epoxy matrix. Static and dynamic compression tests covering strain rates ranging from 0.0008 to 1000 s−1 revealed a pronounced strain rate sensitivity for all AHBP/epoxy systems. The AHBP composites all showed an increase of the true peak yield compressive strength with the best improvement associated with the sample with 0.1 wt% of AHBP.

The effect of an aromatic hyperbranched polyester in aeronautical epoxy composites

A glassy hyperbranched polymer (HBPG) was synthesized and dispersed within an aeronautical graded epoxy matrix as toughening agent. This filler is a polyester characterized by a Tg higher then room temperature (∼90 °C) and obtained by means of bulk poly-condensation reaction starting from a diphenolic acid as precursor.HBPG/epoxy systems were prepared considering two concentration levels (0.1 and 5 wt%) and the effects on mechanical properties and fracture toughness were investigated. HBPG induces a limited reduction of the Tg along with an improvement of the fracture toughness performances as indicated by the increase KIC and GIC values.

Synthesis, characterization and evaluation of long-acting hyperbranched cationic polymer clay stabilizer used in water flooding

In the process of waterflooding development, it is of great importance to prevent the clay from hydration swelling and migration dispersion for protecting the formation and improving the water flooding efficiency. For those reasons, we successfully synthesized a cationic clay stabilizer (HBP-QAT) through melting polycondensation and cationic modification with maleic anhydride, diethanolamine, epichlorohydrin, triethylamine, and trimethylolpropane as monomers and p-toluene sulfonic acid as a catalyst. The chemical structure, cation degree, and molecular weight of HBP-QAT were studied by using FTIR, 1H NMR, sodium tetraphenylborate (STBP) back titration, and gel permeation chromatography (GPC). The obtained results showed that HBP-QAT was a hyperbranched unsaturated polyester amide with a low molecular weight and a high cation degree, with corresponding values of 28400, and 44.2%, respectively. The clay stability and durability of HBP-QAT were evaluated by linear anti-swelling, water flushing, and cutting rolling recovery tests. The obtained results showed that HBP-QAT has an excellent anti-washing capacity and a long-term inhibition effect. The initial anti-swelling rate of 1.0 wt% HBP-QAT reached 92.37%, and the anti-swelling rate of 1.0 wt% HBP-QAT also remained at 85% after flushing 10 times with water. Besides, the two cutting rolling recoveries exceed 72%. Most importantly, the inhibition mechanism of HBP-QAT was studied by zeta potential, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), and contact angles analyses, and thus we proposed an inhibition mechanism, presenting as follows. HBP-QAT inhibited the clay hydration swelling by neutralizing negative charges on the surface of the clay particles to compress the electric double layer, strongly adsorbing on the surface of the clay particles, and forming a waterproof polymer membranes, restraining water of intrusion into the clay interlayer.

Effect of hyperbranched poly(citric polyethylene glycol) with different polyethylene glycol chain length on starch sizing and compatibility with blended yarns

ABSTRACTBlend of starch and water‐soluble polyester has been widely used in warp sizing because of its good film‐forming, biodegradability, and adhesion to polyester/cotton blended yarns (T/C). In this study, a series of hyperbranched polyesters poly(citric polyethylene glycol) (PCPEG) with varied chain length of polyethylene glycol (PEG) were prepared with citric acid and PEG at molar ratio of 1:3 and 150 °C for 3 h in vacuum and characterized by Fourier transformed infrared, gel permeation chromatography, and 1H nuclear magnetic resonance. PCPEG blended maize starch (PCPEG/MS) as sizing agent of T/C 80/20 and effects of PEG chain length of PCPEG on the property of the blending sizing agent were studied. Results indicated PCPEG could improve the compatibility between starch and T/C 80/20 and the optimum content of PCPEG as blended sizing agent was 8%. PCPEG not only decreased apparent viscosity of MS paste but also increased viscosity stability of the paste. In addition, with increase of PEG chain length of PCPEG, viscosity stability of PCPEG/MS paste increased, but the value of all adhesion performances of T/C 80/20 after sizing decreased. Long chain of PEG is not good for compatibility between PCPEG and starch. The starch blending PCPEG has potential applications in sizing blended yarns in textile industry. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48928.

Methods of correlation NMR spectroscopy in the study of the structure of hyperbranched polyester BOLTORN H40

Methods of correlation NMR spectroscopy in the study of the structure of hyperbranched polyester BOLTORN H40

A novel, eco-friendly and durable flame-retardant cotton-based hyperbranched polyester derivative

A novel, formaldehyde-free, efficient and durable flame-retardant hyperbranched polyester derivative (HBPPN), containing nitrogen and phosphorus, was synthesized using a second-generation hyperbranched polyester, phosphorous acid and urea. The HBPPN was characterized by FT-IR and nuclear magnetic resonance spectroscopy. The FT-IR spectra indicated that the HBPPN may be grafted onto cotton by covalent bonds, modifying the degradation of the cotton. The flame-retardant properties of the HBPPN-treated cotton fabric were investigated based on vertical flammability, LOI, and cone calorimetry. The LOI value of 160 g/L HBPPN-treated cotton fabric was 39.6%, and the LOI value decreased to 27.3% after 50 laundering cycles, indicating the high durability of the cotton fabric treated with HBPPN. The vertical flammable tests showed that the cotton fabrics treated with HBPPN had short char lengths. The surface morphology of HBPPN-treated cotton fabrics was assessed using SEM. TGA demonstrated that the cotton fabrics treated with HBPPN easily formed char. Cone calorimetry indicated obviously lower values of PHRR and THR relative to those of the untreated cotton fabrics. XRD revealed that treatment with HBPPN did not substantially change the crystalline structure of the cotton. These results confirmed that HBPPN exhibited excellent flame retardancy and high durability.

Polyglycerol Hyperbranched Polyesters: Synthesis, Properties and Pharmaceutical and Biomedical Applications.

In a century when environmental pollution is a major issue, polymers issued from bio-based monomers have gained important interest, as they are expected to be environment-friendly, and biocompatible, with non-toxic degradation products. In parallel, hyperbranched polymers have emerged as an easily accessible alternative to dendrimers with numerous potential applications. Glycerol (Gly) is a natural, low-cost, trifunctional monomer, with a production expected to grow significantly, and thus an excellent candidate for the synthesis of hyperbranched polyesters for pharmaceutical and biomedical applications. In the present article, we review the synthesis, properties, and applications of glycerol polyesters of aliphatic dicarboxylic acids (from succinic to sebacic acids) as well as the copolymers of glycerol or hyperbranched polyglycerol with poly(lactic acid) and poly(ε-caprolactone). Emphasis was given to summarize the synthetic procedures (monomer molar ratio, used catalysts, temperatures, etc.,) and their effect on the molecular weight, solubility, and thermal and mechanical properties of the prepared hyperbranched polymers. Their applications in pharmaceutical technology as drug carries and in biomedical applications focusing on regenerative medicine are highlighted.

Investigation on the Effect of Hyperbranched Polyester Grafted Graphene Oxide on the Crystallization Behaviors of β-Nucleated Isotactic Polypropylene.

In this article, hyperbranched polyester grafted graphene oxide (GO) was successfully prepared. X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and transmission electron microscopy (TEM) were performed for its characterizations. On the other hand, differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD) were also performed to study its influences on non-isothermal crystallization behaviors of β-nucleated isotactic polypropylene (β-iPP). The grafting ratios of hyperbranched polyester with different supermolecular structures were calculated to be 19.8–24.0 wt %, which increase with the degree of branching. The results showed that the grafting of hyperbranched polyester was advantageous in increasing the crystallization peak temperature Tp and decreasing the crystallization activation energy ΔE of β-iPP/GO composites, which contributed to the iPP’s crystallization process. Moreover, under all cooling rates (2, 5, 10, 20, 40 °C/min), crystallinities of β-iPP/GO were greatly improved after being grafted with hyperbranched polyester, because of the increase of the relative contents of α-phase αc and the average α-crystal sizes.

Synthesis of Poly (Citric Acid-Co-Glycerol) and Its Application as an Inhibitor of CaCO3 Deposition.

This investigation determined a feasible route to prepare hyperbranched polyesters involving citric acid (CA) and glycerol (GLC) monomers (CA-co-GLC) using a thermal polycondensation method. The synthesized copolymer was characterized using Fourier transform infrared spectroscopy (FT-IR), carbon-13 nuclear magnetic resonance spectroscopy, and differential scanning calorimetry. The ability of CA-co-GLC to inhibit deposition of inorganic scales such as calcium carbonate was investigated under varying temperature and pH medium. The evaluation of inhibition efficiency (IE) was conducted using the static scale inhibition method. The mechanism of the inhibitor’s action was investigated via growth solution analysis, measurement conductivity, and analysis of CaCO3 using FT-IR and scanning electron microscopy. The results obtained showed that the CA-co-GLC had good IE at an elevated temperature reaching 75% at 100 °C, pH 7.5, and 10 ppm copolymer dose. Using the same dose, the IE reached 66% at 50 °C and pH 10. The CA-co-GLC did not chelate Ca2+ in water, but led to a change in polymorphism, making it brittle and able to slip easily from the surface. Its action principally prevented the adhesion of calcium carbonate onto the surface.