The structure and application of amine‐terminated hyperbranched polymer shale inhibitor for water‐based drilling fluid

Amine‐terminated hyperbranched polymer (HBP‐NH₂), as an inhibitor in water‐based drilling fluid, is prepared by the polycondensation of diamine AB₂ monomers. The primary amine and secondary amide structures are confirmed by Fourier transform infrared spectroscopy and nuclear magnetic resonance hydrogen spectroscopy. Through time of flight mass spectrometry, the molecular weight of HBP‐NH₂ is mainly distributed in the range of 200–1400. Also, the quasi‐spherical shape and the high temperature resistance (200 °C) performance of HBP‐NH₂ are, respectively, certified through the environmental scanning electron microscope and the thermogravimetric analysis. In the inhibition performance test, the linear expansion rate of sodium bentonite in 3 wt % HBP‐NH₂ aqueous solution is only 11.42%, which is lower than other inhibitors (KCl, FA‐367, and HPAM). Zeta potential analysis shows that HBP‐NH₂ has a strong ability to inhibit the hydration and dispersion of sodium bentonite by protonated primary amine groups. Compared with the base slurry, the absolute value of zeta potential is reduced by 25.5 mV in the slurry containing 3 wt % HBP‐NH₂ at 180 rpm. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45466.     

Crystallization behavior of hyperbranched polyethylenes with different degree of branching

Hyperbranched polyethylenes (HBPEs) with different degree of branching (DB) and similar M_n are used to investigate the effect of branch structure on their crystallization behaviors. The crystal structure, isothermal, and non‐isothermal crystallization kinetics of HBPEs are studied by X‐ray diffraction and differential scanning calorimetry. The isothermal crystallization process is analyzed by the Avrami equation while the non‐isothermal crystallization process is analyzed through the Ozawa and Mo methods. The XRD results indicate that the crystallization ability of HBPEs is weakened with the introduction of branch structure, i.e., the crystallinity of HBPEs decreases with the increase of DB, and even tends to zero. The kinetics results of isothermal and non‐isothermal crystallization verify the peculiar effects of DB on the crystallization process of HBPEs. In detail, a little of branch structure can accelerate the crystallization process of HBPEs, however a large number of branch can inhibit it. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44127.     

Thiol-terminated hyperbranched polymer for DLP 3D printing: Performance evaluation of a low shrinkage photosensitive resin

In order to lower the volume shrinkage of the DLP 3D printing photosensitive resins during printing, a thiol-terminated hyperbranched polymer (T-HBP) was synthesized and introduced into the bisphenol A epoxy acrylate (EA) based photosensitive resin system. The obtained T-HBP was characterized by FTIR and ¹H NMR spectra, and the grafting rate of sulfhydryl was determined. The mechanical properties of the photosensitive resins were measured by tensile and impact strength measurement. The glass transition temperature of the photosensitive resins was analyzed by DSC and the impact fracture surface was observed by SEM. T-HBP exhibited a much lower viscosity than its linear counterparts, and the addition of thiol improved the curing speed of the photosensitive resins. When the amount of T-HBP added was 20 wt%, the shrinkage of the photosensitive resins was reduced by about 45.5% and the impact strength increased by 33.9% compared with the control. The macromolecular spherical structure of T-HBP effectively reduced the functional group density of the photosensitive resins. In addition, the thiol-acrylate photopolymerization introduced by T-HBP further reduced the volume shrinkage of the photosensitive resins.     

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

The 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°).     

Synthesis of a branched photosensitive copolymer and its application for negative‐type photoresists

Novel branched copolymers, poly(styrene‐alt‐maleic anhydride) (BPSMA), were synthesized through mercapto chain‐transfer polymerization with styrene, maleic anhydride (MA), and 4‐vinyl benzyl thiol (VBT). Then, the hydroxyl of hydroxyethyl methacrylate was reacted with MA to synthesize branched photosensitive copolymers, p‐BPSMAs. Fourier transform IR spectroscopy and ¹H‐NMR indicated that the synthesis was successful. Gel permeation chromatography indicated that the molecular weight decreased with increasing content of VBT. The thermal properties were characterized by thermogravimetric analysis; the results show that the thermal decomposition temperature of the BPSMAs was greatly enhanced. Real‐time IR was used to evaluate the UV‐curable kinetics of the p‐BPSMAs; the results show that the p‐BPSMAs could rapidly photopolymerize under UV irradiation in the presence of photoinitiators. Moreover, the photoresist based on the p‐BPSMAs exhibited improved photosensitivity when the VBT content increased, and the photoresist with 12 mol % VBT content had a low value of the dose that retained 50% of the original film thickness (10 mJ/cm²), and a 50‐μm resolution could be achieved compared to a linear photoresist. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42838.     

Preparation of novel dendritic flame‐retardant polymer and its application in EPDM composites

Flame‐retardant polymer, dendritic tetramethylolphosphonium chloride (FR‐DTHPC), was prepared by condensation polymerization between THPC, the monomer we prepared, and boric acid. It was then characterized by Fourier transform infrared spectroscopy, intrinsic viscosity, and matrix assisted laser desorption ionization time of flight mass spectrometer. This FR‐DTHPC was used in the preparation of flame‐retardant ethylene propylene diene monomer (EPDM) composites. Different types of EPDM/FR‐DTHPC composites were prepared with different amounts of FR‐DTHPC. Then, the cure characteristic, tensile properties, flame‐retardance, and thermal stability were researched and compared. Results showed that the addition of this novel additive can improve some mechanical and flame‐retardant properties of EPDM composites. Mechanisms of reinforcing and flame‐retardance were proposed. The dendritic polymer may reduce the amount and size of voids in EPDM composites, and thus may increase their tensile properties. Meanwhile, the degradation products from nitrogen, phosphorus, and boric acid in FR‐DTHPC can increase the amount of carbonaceous layers, and thus can inhibit the pyrolysis degree of EPDM composites during burning and improve their flame‐retardant performance. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40855.     

Polymerization‐induced phase separation and resulting thermomechanical properties of thermosetting/reactive nonlinear polymer blends: A review

Thermosets, which have a highly crosslinked structure, play a pivotal role in high‐performance composite materials because of their excellent mechanical properties, including their high modulus, high strength, and high glass‐transition temperature. In general, however, thermosets are brittle materials with a toughness and elongation at break that are unsatisfactory for many applications, especially at high temperatures. The key factor that can greatly influence the toughness of a thermoset material is its cured microstructure or nanostructure. Recently, it has been revealed that the introduction of a reactive modifier into a multicomponent thermosetting prepolymer is a versatile way to finely tune the polymerization‐induced phase separation (PIPS) and the microstructure and thermomechanical properties of the resulting thermosets. This review focuses first on the advancement of the methods used to study the PIPS of thermosetting prepolymers. I go on to discuss factors influencing the thermodynamic and the kinetic behavior of PIPS and the resulting morphology and thermomechanical properties of thermosetting blends obtained when nonlinear reactive modifiers are incorporated. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

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

Blend 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.     

Cyclodextrin‐dendrimer functionalized polysulfone membrane for the removal of humic acid in water

Commercial polysulfone (PSf) membranes were crosslinked with a β‐cyclodextrin‐poly (propyleneimine) (β‐CD‐PPI) conjugate which had β‐CD pendant arms using trimesoyl chloride (TMC) by interfacial polymerization. The morphology and physicochemical properties of the nanofiltration membranes were characterized using Fourier transform infrared/attenuated total reflectance (FT‐IR/ATR) spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), and cross‐flow filtration system. Water‐contact angle, water‐intake capacity, and rejection capacities of the membranes were evaluated. The β‐CD‐G4 (generation 4)‐PPI‐PSf and β‐CD‐G3 (generation 3)‐PPI‐PSf membranes both exhibited high humic acid rejection of 72% as compared to the commercial PSf which exhibited 57%. The modified membranes were also more hydrophilic (36° to 41°) than PSf (76°). These results suggest that β‐CD‐PPI nanostructures are promising materials for the synthesis of membranes for the removal of humic acid from water. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4428–4439, 2013     

Lignin valorization by forming thermally stimulated shape memory copolymeric elastomers—Partially crystalline hyperbranched polymer as crosslinks

Lignin based thermal‐responsive elastomers were produced by a melt polycondensation reaction with a long alkyl chain hyperbranched poly(ester‐amine‐amide) (B₃‐A₂‐CB₃¹). The effect of lignin content on elastomers properties was investigated. The thermal and mechanical properties of the copolymers were characterized by DMA, DSC, and TGA. The morphology of the copolymer was examined by SEM. Tensile properties were dominated by HBP <25% lignin content while lignin dominated >25% content. The copolymers glass transition temperature (T_g) increased with lignin content. The elastomer with 30% lignin content demonstrated optimal mechanical properties (tensile strength 5.3 MPa, Young's modulus 8.9 MPa, strain at break 301%, and toughness 1.03 GPa). Thermally stimulated dual shape memory effects (SME) of the copolymers were quantified by cyclic thermomechanical tests. The transition temperature (T_trans) of the polymer was able to be controlled (room to body temperature) by varying the amount of lignin added which broadens the range to medical applications. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41103.     

Thermomechanical and chemorheology properties of a thermosetting acrylic/melamine clearcoat modified with a hyperbranched polymer

The work presented here aims at studying the thermomechanical and chemorheological properties of an automotive clearcoat containing an acrylic/melamine resin modified with a hyperbranched poly ester‐amide (HBP) additive. Rheological experiments were conducted at ambient (25°C) and curing temperature (140°C). Dynamic mechanical thermal analysis and hardness measurements were performed to reveal the influence of HBP content on the behavior of the cured samples. It was found that the viscosity of the resin containing HBP samples considerably decreased. Although curing degree and mechanical properties were improved at low HBP loadings, a reverse effect was seen at higher contents. Dynamic rheological results during curing showed that although low amount of HBP resulted in an early gel point (GP), higher HBP loading postponed the GP. This loading‐dependent behavior was explained by the influence of HBP on viscosity and reactivity of the system on which the curing performance was influenced oppositely. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Synthesis of hyperbranched polymers by free radical addition‐coupling polymerization with A3/B2 and A2A′/B2 approaches

Two tribromide compounds, 1,3‐(propanoic acid, 2‐bromo‐)‐2‐(2‐bromo‐1‐oxopropylamino)propyl ester (A 1 ) and trimethylolpropane tris(2‐bromopropionate) (A 2 ), were synthesized. By Cu/N,N,N′,N′,N″‐pentamethyldiethylenetriamine (PMDETA)‐mediated radical addition‐coupling polymerization (RACP) of 2‐methyl‐2‐nitrosopropane (MNP) with the tribromide compounds, two types of hyperbranched polymers were synthesized under mild conditions, respectively. Polymerization degrees of the polymers increased with time gradually, which is in line with a step‐growth polymerization mechanism. By tracing the polymerization process by gel permeation chromatography and NMR analysis, proper reaction conditions to get hyperbranched polymers was obtained. Based on the results of NMR analysis on the polymer chain structure, mechanism of forming hyperbranched polymer has been proposed, which includes formation of carbon radicals from the tribromo monomer through single electron transfer, their reaction with MNP to form nitroxide radicals, and cross‐coupling reaction of the nitroxide radicals with other carbon radicals. The gelation point of the A 2 ‐MNP system is larger than that of the A 1 ‐MNP system, indicating that probability of intramolecular cyclization in A 2 ‐MNP RACP system is higher than the A 1 ‐MNP system. The reactivity of —NHCOCH(CH₃)Br group of A 1 is lower than its two —OCOCH(CH₃)Br groups, and this resulted in longer distance between two adjacent branch points in the hyperbranched polymer of A 1 ‐MNP than the A 2 ‐MNP system. It is possible to adjust the chain structure of RACP‐based hyperbranched polymer by changing the reactivity of the functional groups in A₃ monomer. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41972.     

Surface modification and PEGylation of branched polyethyleneimine for improved biocompatibility

In this article, we report the surface modification of branched polyethyleneimine (PEI) for improved biocompatibility. PEIs with different surface functionalities were synthesized via covalent modification of the PEI amines, including neutralized PEI modified with acetic anhydride, negatively charged PEI modified with succinic anhydride, hydroxylated PEI modified with glycidol, and PEI–poly(ethylene glycol) (PEG) conjugates modified with both PEG and acetic anhydride. The modified PEI derivatives were characterized with ¹H‐NMR, Fourier transform infrared spectroscopy, and ζ‐potential measurements. An in vitro cytotoxicity assay of mouse fibroblasts revealed that the biocompatibility of PEI was significantly improved after these modifications. The neutral and negatively charged PEIs were nontoxic at concentrations up to 200 μg/mL, whereas the pristine PEI was toxic to cells at concentrations as low as 10 μg/mL. The successfully modified PEIs with different surface charges and functionalities may provide a range of opportunities for various biomedical applications. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Synthesis of hyperbranched polybenzoxazoles and their molecular composites with epoxy resins

Hyperbranched aromatic polymers have attracted great attention recently because they combined the processability of hyperbranched polymers and the high‐level performance of aromatic polymers. Here, a one‐pot strategy for the synthesis of hyperbranched Polybenzoxazoles (HBPBOs) by polycondensation of 2,2‐Bis (3‐amino‐4‐hydroxyphenyl) hexafluoropropane and 1,3,5‐benzenetricarboxylic acid in Polyphosphoric acid was reported. The HBPBOs exhibited good solubility in organic solvents because of the branched structure and the flexible hexafluoropropane groups in main chains. The structure and terminal functional groups could be tailored by adjusting the molar ratio of two monomers. FT‐IR, NMR and XRD measurements confirmed the structure of HBPBOs, while thermogravimetric analysis (TGA), UV‐vis, and photoluminescence spectra, combined with the comparison with linear PBOs demonstrated the intriguing optical properties and good thermal stabilities of HBPBOs. The good solubility of HBPBOs also permitted their usage as molecular reinforcement for polymer composites as demonstrated in this study of HBPBOs/epoxy composites. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41942.     

Dendrimer functionalized polysilane: An efficient and recyclable organocatalyst

Polysilane supported dendrimer was efficiently utilized as an organocatalyst for Knoevenagel condensation reaction. Polysilane support was synthesized by the polymerization of trichloromethylsilane. The polypropyleneimine (PPI) dendrimer was grafted on the polymer support by divergent method. The dendrimer was synthesized up to three generations (G3). The dendrimer functionalized polysilane (PS‐PPIG3) was found to contain high concentration of terminal amino groups. The catalytic activity of the PS‐PPIG3 dendrimer was generalized by conducting the Knoevenagel condensation reaction with diverse sets of substrates, and was found to be an efficient organocatalyst. The condensation product could be easily separated from the reaction medium because of the heterogeneous nature of the polymer support. The reaction conditions were optimized, and the catalyst was found to be reusable. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41593.     

Preparation of polyamidoamine dendrons supported on chitosan microspheres and the adsorption of bilirubin

The aim of this study was to prepare a new adsorbent for bilirubin (BR); low generation (G, G ≤4) hexanediamine‐containing polyamidoamine (PAMAM) dendrons were supported on chitosan (CS) microspheres (CS‐Gn, n = 0,1,2,3,4). The adsorption properties of this novel adsorbent for BR in aqueous solution were examined. The adsorption percentages were over 70% at 0.5 h and over 90% at 1 h. The adsorption capacity was up to 43 mg/g and was not yet saturated. The BR adsorption increased with increasing temperature and increasing BR initial concentration and was the highest at pH 7.4; it decreased slightly with increasing ionic strength and occurred even in the presence of bovine serum albumin (BSA). We observed that the CS–Gn microspheres had satisfactory competitive abilities with BSA, although the adsorption percentage decreased a certain extent in the presence of BSA. In addition, the CS–Gn microspheres were easier to prepare than the usual PAMAM dendrimers. In summary, this adsorbent is a promising biomedical material for BR removal for artificial liver supported systems. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Synthesis and characterization of a carboxyl‐terminated waterborne hyperbranched polymer and its coordination behavior with chromium(III)

Despite its irreplaceable position in the leather industry, chrome tanning has been listed in the procession of limitation. The serious environmental pollution caused by chrome tanning through the residual chrome it leaves in wastewater has attracted great attention. To improve the absorption of chrome and reduce chromium emission, a novel hyperbranched ligand was synthesized and characterized. The impact elements of the coordination process between the hyperbranched oligomer and Cr(III) was investigated, and the characteristics of the complex are also discussed. This hyperbranched oligomer had a low molecular weight (weight‐average molecular weight = 2125) and narrow molecular weight distribution (PDI = 1.21). The time required for the coordination process between the hyperbranched oligomer and Cr(III) was around 6 h, and the optimum pH was 4.0. Moreover, the complex exhibited alkali resistance and fair resistance to oxidation; this suggested that this developed hyperbranched ligand is a potential masking agent or tanning auxiliary for chrome tanning and will enable improvements in chromium absorption. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40117.     

Nanofibrous nonwovens based on dendritic‐linear‐dendritic poly(ethylene glycol) hybrids

Dendritic‐linear‐dendritic (DLD) hybrids are highly functional materials combining the properties of linear and dendritic polymers. Attempts to electrospin DLD polymers composed of hyperbranched dendritic blocks of 2,2‐bis(hydroxymethyl) propionic acid on a linear poly(ethylene glycol) core proved unsuccessful. Nevertheless, when these DLD hybrids were blended with an array of different biodegradable polymers as entanglement enhancers, nanofibrous nonwovens were successfully prepared by electrospinning. The pseudogeneration degree of the DLDs, the nature of the co‐electrospun polymer and the solvent systems used for the preparation of the electrospinning solutions exerted a significant effect on the diameter and morphology of the electrospun fibers. It is worth‐noting that aqueous solutions of the DLD polymers and only 1% (w/v) poly(ethylene oxide) resulted in the production of smoother and thinner nanofibers. Such dendritic nanofibrous scaffolds can be promising materials for biomedical applications due to their biocompatibility, biodegradability, multifunctionality, and advanced structural architecture. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45949.     

Hyperbranched polyester polyol modified with polylactic acid

In this study the modification of a hyperbranched polyester polyol of second generation (HBP2G) with polylactic acid (PLA) was carried out. The proportions employed of PLA were: 10 (HBP2G90), 25 (HBP2G75), 40 (HBP2G60), and 55 wt % (HBP2G45). The materials obtained were characterized by acid value, hydroxyl value, infrared, nuclear magnetic resonance (NMR), chromatography exclusion size (SEC), dynamic light scattering, thermogravimetric, differential scanning calorimetry, and rheology analyses. The analyses of the acid values and hydroxyl values showed that the reaction between HBP2G and PLA occurred. The greater modification degree was 92.00%. The NMR spectrum shows that evidently the PLA was grafted onto the HBP2G. The SEC analysis revealed that all samples presented values ??of average molecular weight (M_n) and weight average molecular weight (M_w) higher than the HBP2G. The thermal stability of the materials increased with respect to HBP2G and it was independent of the modification degree. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41589.     

An epoxy‐ended hyperbranched polymer as a new modifier for toughening and reinforcing in epoxy resin

A new epoxy‐ended hyperbranched polyether (HBPEE) with aromatic skeletons was synthesized through one‐step proton transfer polymerization. The structure of HBPEE was confirmed by Fourier transform infrared spectroscopy (FTIR), and nuclear magnetic resonance (NMR) measurements. It was proved to be one high efficient modifier in toughening and reinforcing epoxy matrix. In particular, unlike most other hyperbranched modifiers, the glass transition temperature (T_g) was also increased. Compared with the neat DGEBA, the hybrid curing systems showed excellent balanced mechanical properties at 5 wt % HBPEE loading. The great improvements were attributed to the increased cross‐linking density, rigid skeletons, and the molecule‐scale cavities brought by the reactive HBPEE, which were confirmed by dynamical mechanical analysis (DMA) and thermal mechanical analysis (TMA). Furthermore, because of the reactivity of HBPEE, the hybrids inclined to form a homogenous system after the curing. DMA and scanning electron microscopy (SEM) results revealed that no phase separation occurred in the DGEBA/HBPEE hybrids after the introduction of reactive HBPEE. SEM also confirmed that the addition of HBPEE could enhance the toughness of epoxy materials as evident from fibril formation. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1064‐1073, 2013