Hydroxyl-terminated Hyperbranched Polymer Research Articles

Novel hydroxyl-terminated hyperbranched polymer as a synergistic modifier with tannin for preparation of casein-based films with superior performance

A hyperbranched poly (titanium oxide) (HBPTi) with hydroxyl terminal groups was synthesized via polycondensation reaction as a synergistic modifier with tannin to promote performance of casein-based composite film. The synergistic effects of HBPTis, acquiring different hyperbranched structures, with tannin on the microstructure, mechanical characteristics, barrier against water vapor, and thermal stability of casein-based film were investigated in this work. The tensile strength of the composite films increased from 7.6 MPa to 22.1 MPa, which accounts for 190.79 % increase after the addition of HBPTi compared to casein-tannin films modified with glycerol. The casein-tannin films with the help of HBPTi presented excellent water vapor permeation, thermal stability, and showed nearly 100 % UV absorption in the range 200–400 nm. Additionally, the microstructure of HBPTi modified casein-tannin films tend to be more compact due to the promoted interaction of casein-tannin composite aided by covalent bonding and/or other types of bonding between casein, tannin and HBPTi. Therefore, associative modification using such hyperbranched polymers and tannins provides extendable application value for casein-based films especially as food packaging materials and for other fields as well.

Influence of Hydroxyl-Terminated Hyperbranched Polymer and Coupling Agent on the Performance of SF/PLA Composites

ABSTRACT Herein, a hydroxyl-terminated hyperbranched polymer (HPN) with abundant terminal hydroxyl groups was employed to modify straw-plastic composites and studied the effect of HPN concentration on straw fiber reinforced polylactic acid (SF/PLA). Silane coupling agent (CA) was used to improve the interfacial compatibility between SF, HPN and PLA matrix. The mechanical strength, thermal properties and water resistance of different SF/PLA composites were tested and analyzed. When the concentration of HPN is 6%, the HPN-SF/PLA has the best mechanical strength index. HPN modification, CA modification and the combination of both have positive effect on improving mechanical performance. Compared with the UN-SF/PLA, the tensile, flexural and impact strength of HPN+CA-SF/PLA composites were increased by 24.7%,16.6% and 10.8%, respectively. The crystallinity of SF/PLA treated with HPN, CA, and their combination increased from 28% to 29.4%, 36.9%, and 42.3%, respectively. However, low melting point of HPN caused a decrease in the Tg, Tm, Tc, Td5% and Tdmax of SF/PLA. These characteristic temperatures can be enhanced by adding CA for co-modification. In addition, the three modified approach were able to enhance the water resistance of SF/PLA composites due to the reduction of the number of hydroxyl groups on the SF surface and the enhancement of the interfacial bonding properties.

The Synthesis of Nonionic Hyperbranched Organosilicone Surfactant and Characterization of Its Wetting Ability

In this research, the epoxy silicone oil and self-made hydroxyl-terminated hyperbranched polymer (HBP-OH) were used to synthesis the nonionic hyperbranched organosilicone surfactant (NHSi). The molar rate of hydroxyl groups of HBP-OH and epoxy groups of epoxy silicon oil (n-OH: n-epoxy) was adjusted from 5:1~60:1 to prepare a series of NHSi. The Gel Permeation Chromatography (GPC), Fourier Transform Infrared Spectroscopy (FT-IR), contact angle measuring instrument, surface tensiometer and Scanning Electron Microscope (SEM) were employed to characterize the structure and property of HBP-OH and NHSi. GPC analysis indicated that the Mn of HBP-OH was 340.5. FT-IR analysis showed that with the increase of molar rate of n-OH:n-epoxy, the peak intensity of –OH increased. The prepared NHSi was then used to prepare the water solution. The lowest surface tension of NHSi solution was 24.71 mN·m−1 when the n-OH:n-epoxy was 30:1 in the preparation process. The minimum water contact angle of waterborne polyurethane (WPU) emulsion by adding 2% of NHSi was 14.85° on the surface of glass. The wetting experiments showed that the NHSi has good wetting ability to fixed sea-island superfine fiber synthetic material.

The effect of self-synthesized hydroxyl-terminated hyperbranched polymer interface layer on the properties of carbon fiber reinforced epoxy composites

A simple and green method to functionalize carbon fiber (CF) with hydroxyl-terminated hyperbranched polymer (HTHBP) synthesized directly through one-pot condensation polycondensation between isophorone diisocyanate (IPDI) and tris (hydroxymethyl) aminomethane (TOAM) was reported. The covalent grafting of HTHBP on the CF surface can greatly increase the polar functional groups, roughness and wettability of CF surface, thereby resulting to significant enhancement of interfacial properties of composites. After grafting, the interlaminar shear strength (ILSS), interfacial shear strength (IFSS) and impact strength of CFs/epoxy composites increased from 58.6 to 81.8 MPa, 48.8 to 87.8 MPa and 55.7 to 76.9 kJ·m−2, respectively. Furthermore, this surface functionalization process could remedy the single fiber tensile strength. The interfacial reinforcing mechanism was also revealed by analyzing interfacial microstructure. This research provided a thought that constructing a continuous gradient modulus interphase layer with strong physicochemical interaction and good wettability by a simple and green method, which could reinforce the interfacial performance and have a bright prospect application in high-performance composite.

Synthesis of novel cationic fluoroalkyl-terminated hyperbranched polyurethane latex and morphology, physical properties of its latex film

Novel cationic fluoroalkyl-terminated hyperbranched polyurethane (CHBPUF) latex was synthesized by graft reaction of perfluorohexyl ethyl alcohol and hyperbranched polyurethane (CHBPU), which was previously prepared from interaction between hydroxyl-terminated hyperbranched polymer and PU prepolymer manufactured via the acetone process, as well as using neutralization, adding water, and high-speed stirring operations. We characterized the resultants and investigated its surface properties by IR, NMR, XRD, TEM, TGA, DSC, FE-SEM, AFM, XPS, and contact angle measurements, etc. IR and NMR tests confirmed that the fluorinated fragments had been grafted onto the tail end of CHBPU. XRD, TEM, DSC, and FE-SEM results all accounted for there were multi-crystals in CPU, CHBPU and CHBPUF. TGA result showed that thermal stabilities of the CPU, CHBPU, and CHBPUF latex films were enhanced in turn. XPS and AFM analyses demonstrated that the fluorine-containing segments from the CHBPUF terminals were likely to migrate and enrich at the film-air surface of the CHBPUF latex film, which made water contact angle and water absorption of the CHBPUF film be as 108.9° and 13.9%, respectively, compared to those of the CPU film (90.4° and 97.5%). This indicates that water resistance of the CPU film can be efficiently enhanced by fluorinated polyurethane with novel fluoroalkyl-terminated hyperbranched structure and thus CHBPUF latex can find potential application in hydrophobic coating field.

Synthesis and characterization of novel fluoroalkyl-terminated hyperbranched polyurethane latex

Waterborne polyurethane (PU) emulsions are widely used in various fields and the demand for them is ever-increasing over the years. However, the hydrophilic chain extender inevitably bonded into the PU backbone can affect the water tolerance of PU. Thus, it is of great importance to improve PU water resistance effectively. Herein, novel fluoroalkyl-terminated hyperbranched polyurethane (HBPUF) latex was accordingly synthesized by graft reaction of perfluorohexyl ethyl alcohol and hyperbranched polyurethane (HBPU), which was previously obtained from interaction between hydroxyl-terminated hyperbranched polymer and PU prepolymer manufactured via the acetone process, as well as using neutralization, adding water, and high-speed stirring operations. We characterized the resultants and investigated its surface properties by IR, NMR, TEM, XRD, TGA, DSC, FE-SEM, AFM, XPS, and contact angle measurements, etc. IR and NMR tests confirmed that the fluorinated fragments had been grafted onto the tail end of HBPU. TEM, XRD, DSC, and FE-SEM results all accounted for the fact that there were multi-crystals in PU, HBPU and HBPUF. TGA results showed that thermal stabilities of the PU, HBPU, and HBPUF latex films were enhanced in turn. XPS and AFM analyses demonstrated that the fluorine-containing segments from the HBPUF terminals were prone to migrate and enrich on the film-air surface of the HBPUF latex film, which made water contact angle and water absorption of the HBPUF film be as 113.9° and 11.1%, respectively, compared to those of the PU film (77.8° and 136.2%). This research indicates that water resistance of the PU film can be efficiently enhanced by fluorinated polyurethane with novel fluoroalkyl-terminated hyperbranched structure.

Structural and Interfacial Properties of Hyperbranched-Linear Polymer Surfactant.

With oleic acid grafting modification, a series of hyperbranched-linear polymer surfactants (HLPS) were prepared by hydroxyl-terminated hyperbranched polymer (HBP), which was gained through a step synthesis method using trimethylolpropane and AB2 monomer. The AB2 monomers were obtained through the Michael addition reaction of methyl acrylate and diethanol amine. The structures of HLPS were characterised by Fourier transform infrared spectrophotometer and nuclear magnetic resonance (NMR), which indicated that HBP was successfully modified by oleic acid. Furthermore, the properties of surface tension and critical micelle concentration of HLPS solution showed that HLPS can significantly reduce the surface tension of water. The morphology of the HLPS solution was characterised by dynamic light scattering, which revealed that HLPS exhibited a nonmonotonic appearance in particle size at different scattering angles owing to the different replaced linear portions. The relationships of the surface pressure to monolayer area and time were measured using the Langmuir–Blodgett instrument, which showed that the surface tension of monolayer molecules increased with the increasing of hydrophobic groups. In addition, the interface conditions of different replaced HLPS solutions were simulated.Electronic supplementary materialThe online version of this article (doi:10.1007/s11743-014-1592-3) contains supplementary material, which is available to authorized users.

Formulation and Characterization of epoxidized hydroxyl-terminated hyperbranched polyester and its application in waterborne epoxy resin

A novel epoxidized hydroxyl-terminated hyperbranched polymer (HPEEX) was formulated from epichlorohydrin and hydroxy-terminated hyperbranched polyester (HPE) based on trimethylol propane (TMP) and AB2 monomer. The obtained HPEEX was characterized with FT-IR, 1HNMR spectroscopy, TG, WAXD and GPC analysis. Results showed that the HPEEX was formulated as expected and its molecular weight and intrinsic viscosity were 3,789 g/mol and 3.96 mL/g, respectively. Meanwhile, the HPEEX was used as cross-linking agent in the preparation of waterborne epoxy resins. Performance of the HPEEX modified epoxy resin aqueous (EP-H) dispersions and their films was evaluated by various tests. It was found that with incorporation of hyperbranched polymer into the epoxy macromolecular chain, the EP-H films exhibited excellent hardness and water-proof performance: the hardness was as high as 96 (Shore A), and the contact angle of water on the surface of this kind of film was as high as 71°, resulting from branched structure, higher functionality of HPEEX, better cross-linking density and large number of hydrogen bonding in this epoxy system.

Toughening of brittle poly(lactide) with hyperbranched poly(ester-amide) and isocyanate-terminated prepolymer of polybutadiene

The use of polylactide (PLA) in durable applications is currently being hampered by its brittleness and low impact strength. In this study, the effects on mechanical properties of two potential toughening agents for PLA, i.e., hydroxyl-terminated hyperbranched poly (ester amide) and isocyanate-terminated prepolymer of butadiene (ITPB), alone and in combination, are investigated with the aim of making tough PLA blends for use in durable non-food applications such as automotive interior. Synergistic effects in impact strength were observed in PLA ternary blends containing hyperbranched polymer (HBP) and ITPB. Impact strength of the PLA/HBP/ITPB ternary blend was improved by over 86 %, while the elongation at break was increased by over 100 %. Physical and chemical interactions between the hydroxyl-terminated HBP and the ITPB may be responsible for the observed synergistic effect and improvements in impact strength. Tensile, flexural, thermal, and thermo-mechanical properties of the PLA/HBP blends with varying amounts of the ITPB were studied. Scanning electron microscopy images showed evidence of stretched polymer which may indicate that the fracture behavior of PLA changed from brittle to ductile in the PLA/HBP/ITPB ternary blends.

Effect of NCO/OH ratio and Ce‐Zr nanoparticles on the thermo‐mechanical properties of hyperbranched polyurethane urea coatings

AbstractThe present study describes the effect of NCO/OH ratio and addition of Cerium (Ce)‐Zirconium (Zr) mixed oxide nanoparticles on the properties of Hyperbranched Polyurethane Urea (HBPUU) Coatings. Initially a hydroxyl terminated hyperbranched polymer (HTBP) was synthesized through A3 + CB2 approach. The HTBP and Ce‐Zr nanopowder dispersed HTBP, both were reacted with hexamethylene diisocyanate (HDI) separately; at various NCO/OH eq. ratios to get different NCO terminated HBPU and HBPU/Ce‐Zr hybrid prepolymers. These prepolymers were used for the preparation of HBPUU and HBPUU/Ce‐Zr hybrid coating films through moisture curing. The techniques such as 1H NMR, 13C NMR, FT‐IR, and XRD have been used for structural information while Dynamic mechanical and thermal analyzer (DMTA), Thermogravimetric analysis (TGA) and Universal testing machine (UTM) have been used for evaluation of thermo‐mechanical properties. The combined spectroscopic investigations results indicate the formation of HBPUU network with a degree of branching of 76% while FT‐IR deconvolution results indicates the formation of more hydrogen bonded structure with increasing NCO/OH ratio. The XRD and FT‐IR studies confirm the presence of Ce‐Zr mixed nanoparticles in the HBPUU hybrids. As per TGA and DMTA analysis the thermal stability, char residue, storage modulus (E', material stiffness) and glass transition temperature (Tg), increases with increasing NCO/OH ratio and Ce‐Zr nanoparticle loading in HBPUU coatings. In general, UTM data suggest that the tensile strength increases and per cent elongation at break decreases with increasing the NCO/OH ratio and addition level of nanoparticles in HBPUU coatings. Copyright © 2009 John Wiley & Sons, Ltd.

Synthesis, Characterization and Mechanical Properties of Hydroxyl-Terminated Hyperbranched Polymer Graft Polyether-Based Aliphatic Polyurethane Elastomer

Hydroxyl-terminated hyperbranched polyurethane elastomer (HBPU) was synthesized by graft copolymerization of hyperbranched poly (amine-ester) polyols(HPAE) and polyether-based aliphatic polyurethane prepolymer(PPU), and the PPU was synthesized by step polymerization of isophorone diisocyanate(IPDI) with polyethylene glycol(PEG) and dibutyltin dilaurate(DBTDL) as catalyst. The FT-IR spectroscopy, TGA and XRD were used to characterize the structure, thermal properties and crystallinity of HBPU. The mechanical properties of the elastomers were conducted on a testing machine. Microphase separation of HBPU film surface was studied by atomic force microscopy (AFM). The experimental results showed that the HBPU took on excellent hydrogen bonding and mechanical properties. The tensile strength of HBPU elastomer reached to 20.6MPa, which increased by 41.2 times than that of PPU elastomer. And the elongation at break was as high as 251.3%.

A new strategy for controlling shrinkage of DGEBA resins cured by cationic copolymerization with hydroxyl‐terminated hyperbranched polymers and ytterbium triflate as an initiator

AbstractWe report a novel strategy for preparing epoxy thermosetting systems with low shrinkage and improved flexibility and degradability. Diglycidyl ether of bisphenol A (DGEBA) resin was cured with different proportions of hydroxyl‐terminated hyperbranched polymer (HBP), using ytterbium triflate as a cationic initiator. The curing process was studied using differential scanning calorimetry and thermomechanical analysis. Characterization of the resulting materials was evaluated using DSC, thermogravimetric analysis, and dynamic mechanical thermal analysis, and the fracture surface was studied using scanning electron microscopy (SEM). When DGEBA is modified with HBP, it shows a homogeneous morphology and the HBP is incorporated chemically into the network, because hydroxyl groups can react with epoxides under cationic conditions. Higher proportions of HBP reduce the glass transition temperature (Tg) and thermal stability and increase the flexibility. When the proportion of HBP in the curing mixture is increased, the degree of shrinkage is reduced significantly and expansion can be observed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

A New Hyperbranched Poly(arylene−ether−ketone−imide): Synthesis, Chain-End Functionalization, and Blending with a Bis(maleimide)

While aromatic polyimides have found widespread use as high-performance polymers, the present work addressed the need for organosoluble pre-imidized materials through the use of a hyperbranching scheme. The AB2 monomer, N-[3,5-bis(4-hydroxybenzoyl)benzene]-4-fluorophthalimide, was prepared from 4-fluoroisophthalic anhydride and 3,5-bis(4-hydroxybenzoyl)aniline. The latter was synthesized in three steps starting from commercially available 5-nitroisophthalic acid. The AB2 monomer was then polymerized via aromatic fluoride-displacement reaction to afford the corresponding hydroxyl-terminated hyperbranched polymer, HT-PAEKI, which was then functionalized with allyl and propargyl bromides as well as epichlorohydrin to afford allyl-terminated AT-PAEKI, propargyl-terminated PT-PAEKI, and epoxy (glycidyl)-terminated ET-PAEKI, in that order. All hyperbranched poly(ether−ketone−imide)s were soluble in common organic solvents. Intrinsic viscosities of HT-, AT-, PT-, and ET-PAEKI in NMP were 0.13, 0.08, 0.08, and 0....