超支化聚酯在环氧树脂改性中的应用

超支化聚合物是一类具有三维树形结构的高度支化的大分子。由于其独特的结构和性能以及可实现工业化生产的潜力,超支化聚合物已经成为高分子材料领域研究的热点之一,并且得到了越来越多的关注。作为一类非常重要的超支化聚合物,超支化聚酯(HBPE)引起了研究人员的极大兴趣。目前,HBPE已经在众多领域获得应用,特别是在环氧树脂改性中的研究发展迅速。综述了HBPE作为改性剂在环氧树脂中的应用研究进展,同时对HBPE在环氧树脂和其他热固性树脂改性中的应用研究方向作了展望。     

Effect of acid groups in hydroxyl functional resins on the properties of polyester-urethane powder coatings

The concept of using hyperbranched polymers as scaffolds for solid thermoset resin applications is de-scribed. A series of semi-crystalline methacrylae-functional aliphaic poly-esters has been synthesized and characterized for applications as solid thermoset resins, e.g., powder coating resins. The polyester resin have been croslinked by UV irradiation producing either amorphous or semi-crystalline crosslinked films depending on the initial structure. The esins are based on hyperbranced aliphatic polyesters onto which crystaline linear aliphatic polyester chains have been grafted and end-capped with methacrylate moieties. The resins exhibit a rheological behavior suitable for low temperature curing powder coaings, i.e., films that can be readily formed and UV cured a temperatures below 80 °C. 2000 Lake Park Drive Smyrna GA 30080 E-Mails: bin.wu@ucb-group.com and sanilay.padaki@ucb-group.com     

Novel concept for low temperature curing powder coatings based on hyperbranched polyesters

The concept of using hyperbranched polymers as scaffolds for solid thermoset resin applications is de-scribed. A series of semi-crystalline methacrylate-functional aliphatic poly-esters has been synthesized and characterized for applications as solid thermoset resing, e.g., powder coating resins. The polyester resins have been crosslinked by UV irradiation producing either amorphous or semi-crystalline crosslinked films depending on the initial structure. The resins are based on hyperbranched aliphatic polyesters onto which crystalline linear aliphatic polyester chains have been grafted and end-capped with methacrylate moieties. The resins exhibit a rheological behavior suitable for low temperature curing powder coatings, i.e., films that can be readily formed and UV cured at temperatures below 80°C. Dept. of Polymer Technology, SE-100 44 Stockholm, Sweden. E-mails: matskg@polymer.kth.se. mave@polymer.kth.se, and andult@polymer.kth.se.     

New coating systems based on vinyl ether‐ and oxetane‐modified hyperbranched polyesters

A series of hyperbranched aliphatic‐aromatic polyesters has been synthesized which contain vinyl ether or oxetane functionalities as curable groups. We investigated the curing behavior of these multifunctional polymers in the presence of reactive diluents in order to analyze the possibility of their application in high solids coatings. The vinyl ether‐modified hyperbranched polyesters with a high degree of modification yield the best coatings. Furthermore, coating systems containing vinyl ether‐modified hyperbranched polyesters and triethyleneglycol divinyl ether (DVE‐3) as reactive diluent showed a better performance compared to those containing 4‐hydroxybutyl vinyl ether (HBVE). Real time FT‐IR studies revealed a high conversion of functional groups (76%) for the cationic curing with DVE‐3. On the other hand, the curing reaction of the functional hyperbranched polymers without the presence of any reactive diluent stopped at 32% conversion of functional groups due to the reduced mobility of the polymer. The vinyl ether‐modified hyperbranched polyester could be cured also radically in the presence of diethyl maleate (DEM) as reactive diluent, whereas the curing of the oxetane‐modified polyesters was very slow and incomplete in all attempts.     

Aliphatic hyperbranched polyesters based on 2,2-bis(methylol)propionic acid—Determination of structure, solution and bulk properties

Due to their highly branched structure and the large number of functional groups hyperbranched polymers possess unique properties that make them interesting for uses in a wide variety of applications. Some of the most widely investigated hyperbranched polymers are the polyesters based on 2,2-bis(methylol)propionic acid. In this paper we present the results of characterization studies of hyperbranched polyesters based on 2,2-bis(methylol)propionic acid which show that they are very complex products with a multidimensional distribution of various properties. The influence of the synthesis conditions on the structure and molar-mass characteristics of hyperbranched polyesters as well as the findings that allow a thorough understanding of the structure-property relationships are reviewed in detail.     

Hyperbranched aromatic polyesters: From synthesis to applications

During the last two decades, hyperbranched polymers have become the focus of interdisciplinary research, and received considerable attention due to their unique chemical and physical properties as well as their potential applications. As an important class of hyperbranched polymers, aromatic hyperbranched polyesters have attracted increased interest and are intensively studied because of their excellent thermal stability, chemical resistance, and mechanical properties. This article reviews the developments in synthesis, modifications, and applications of aromatic hyperbranched polyesters.     

环氧树脂改性超支化聚酯的合成及性能

以偏苯三酸酐、环氧氯丙烷及甲基丙烯酸缩水甘油酯为原料合成了超支化聚酯(HBP),再通过超支化聚合物的羧基与环氧树脂环氧基的反应得到环氧改性超支化聚合物;用GPC1、H-NMR、DSC、TGA表征了环氧改性超支化聚合物的结构和热性能;比较了不同环氧树脂用量改性前后树脂的光反应活性以及光固化涂层的耐擦洗性和硬度,测定了凝胶率-曝光时间曲线;以环氧改性超支化聚合物配制了光刻胶,在混合光源以及接触曝光的条件下,分辨率达到2~3μm,且图像十分清晰,断面整齐。环氧树脂用量为HBP羧基物质量的70%左右时,改性的超支化聚酯的光固化活性有明显提高,力学性能得到明显改进。     

超支化聚合物改性环氧树脂的研究进展

超支化聚合物因其独特的结构和性能特点,已在众多领域得到了广泛的应用,尤其是在热固性树脂的改性中的应用,可作为热固性树脂的增韧剂。该文介绍了环氧树脂的性能特点及应用,超支化聚合物的结构及特点,着重论述了近年来超支化聚合物在改性环氧树脂力学性能、固化行为及热性能方面的研究进展,并指出了超支化聚合物在环氧树脂和其它热固性树脂改性方面的发展方向。     

Process structure property relationships in electron beam generated cellular materials

Cellular materials were generated from radiation curable compositions of acrylated monomers and oligomers utilizing electron beam irradiation techniques. The relationships between the processing variables, the chemical compositions, and the final properties of these materials were examined. Two methods of producing these materials were compared. One process consists of frothing the radiation curable mixture before irradiation by a mixing technique and then casting the unpolymerized froth onto a substrate where it can be subsequently cured using electron beam radiation. Another process relies on a surfactant to stabilize the cellular structure before irradiation. It was found that the quality of the cellular structures produced by these techniques is highly dependent on the viscosity of the radiation curable mixture. A detailed outline of these processes with the resultant structures and properties of these cellular materials is presented along with comparison with other cellular material generation processes. © 1996 John Wiley & Sons, Inc.     

超支化聚合物的溶液相行为与涂料应用

通过新的合成方法相继制备超支化聚酯、聚醚、聚酯酰胺及聚丙烯酸酯等,其结构越来越复杂,应用也越来越广泛.本文概述了超支化聚合物椭球型的结构特征和无序支化到可控的制备方法的发展.重点介绍了其溶液无链缠绕的流变特性和相行为研究进展,通过末端官能团的改性可改变超支化聚合物的溶解性、流变性和功能化.对其在涂料领域的应用如固化剂、...     

Hyperbranched Polymers for Coating Applications: A Review

In the present era, hyperbranched polymers have been received much progress in the structural understanding and their unique chemical and physical properties as well as their potential applications in coatings. In a new perspective, low Volatile Organic Compounds (VOC) coatings and films with previously nonachievable properties can now be produced due to the innovation of a new class of macromolecular architecture, called hyperbranched polymers revolution. This review describes notable efforts on the synthesis of hyperbranched polymers, characterization techniques, and some of the key approaches that have been made in the application of these hyperbranched polymers in the areas of PU coatings.     

Hyperbranched polyesters with internal and exo‐presented hydrogen‐bond acidic sensor groups for surface acoustic wave sensors

Three hyperbranched aromatic polyesters carrying both internal and exo‐presented hydrogen‐bond acidic phenol, carboxylic acid, or mixed phenol/acetoxy groups were coated onto 500 MHz surface acoustic wave (SAW) sensor platforms, and sensor responses to the nerve agent simulant dimethyl methylphosphonate (DMMP) and the explosives simulant dinitrotoluene (DNT) were studied. All three hyperbranched polyesters gave strong responses to DMMP, and the hyperbranched polyester carrying carboxylic acid groups gave a particularly strong response. The hyperbranched polyester carrying phenol groups gave the best response to DNT of the three polymers studied. The DMMP and DNT responses of the three hyperbranched polyesters were also compared with hyperbranched SAW sensor polymers carrying exo‐presented phenolic sensor groups only, and also with linear SAW sensor polymers carrying phenolic sensor groups. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

环境友好涂料成膜物结构更新技术

开发环境友好涂料用新型油性成膜物，如液晶树脂、UV固化超支化聚合物，触变性树脂等。并采用IPN、基团转移聚合、微胶合成新工艺。开发新型元素有机物，制备功能性树脂。开发水性氟树脂、水性聚酯、水性环氧树脂、水性丙烯酸树脂及其他水性成膜物。     

Reactive core/shell type hyperbranched blockcopolyethers as new liquid rubbers for epoxy toughening

Novel reactive core/shell-type hyperbranched blockcopolyethers were tailored as new class of liquid rubbers useful as flexibilizers and toughening agents of anhydride-cured epoxy resins. Anionic ring-opening polymerization of glycidol onto a six-arm star poly(propylene oxide-block-ethylene oxide) afforded hyperbranched polyether cores as macroinitiators for propylene oxide graft copolymerization. The hydroxy end groups of the resulting polyether-polyols have been modified in order to prepare stearate, hydroxy benzoate and epoxy derivatives. The modification afforded reactivity and polarity design which has been the key to improved blend performance with epoxy resins. In comparison to conventional hyperbranched epoxy-terminated polyesters, the influence of molecular architectures on thermal, mechanical and morphological properties of hexahydrophthalic acid anhydride-cured bisphenol-A diglycidylether was examined. As a function of polarity and reactivity design, it was possible to control phase separation and to vary mechanical properties from highly flexible to stiff and tough.     

UV固化水性高支化聚酯

以偏苯三酸酐(TMA)、环氧氯丙烷(ECH)、甲基丙烯酸缩水甘油酯(GMA)、三乙胺(TEA)合成了末端羧基与氨基不同比例的一系列可UV固化的高支化聚酯,研究了末端官能团对合成产物水溶性、粘度以及凝胶转化率的影响。结果表明:高支化聚酯的水溶性随着末端的羧基增多而变大,光固化速度与末端的丙烯酰基官能度有关。水作为溶剂引入10%后,可以将树脂的粘度从6500mPa·s降低到3200mPa·s。     

Tannic acid-based tough hyperbranched epoxy thermoset as an advanced environmentally sustainable high-performing material

Bio-based resources are progressively replacing those of petroleum-based to address the detrimental impact on environment and health issues. In this regard, hyperbranched epoxy resins with three different compositions were synthesized by simple polycondensation reaction of bio-based branching reactant, diethanolamide of gallic acid with bisphenol-A, and epichlorohydrin. Diethanolamide of gallic acid was obtained from the reaction between tannic acid and diethanol amine in the presence of sodium methoxide catalyst. FTIR, ¹H NMR, and ¹³C NMR spectroscopic analyses were employed to confirm the structure of branching unit and hyperbranched resins. Poly(amido amine)-cured hyperbranched epoxy thermosets exhibited superior properties, such as tensile strength (45–57.2 against 38.5 MPa), elongation-at-break (16.3–24.2 against 5 %), scratch hardness (>10 against 7 kg), toughness (577.8–859.1 against 150.2 MPa), tensile adhesive strength (1647–2086 against 581 MPa), and biodegradability (17.6–31 against 2.2 %), compared with the conventional bisphenol-A-based epoxy, prepared under the same conditions. These results simply indicate the advantageous of the bio-based moiety and hyperbranched architecture on the overall performance of the thermosets. Moreover, good antioxidative response of these thermosets expands their applications as protective coatings and adhesive materials. Thus, diethanolamide of gallic acid-based hyperbranched epoxy thermoset can be used as potent ecofriendly advanced material in multifaceted applications.     

Solid‐state structure and properties of hyperbranched polyols

Structure–property relationships were studied in a series of hyperbranched polyesters based on dimethoxypropionic acid with ethoxylated pentaerythritol as the core. In DSC thermograms, all the polyols exhibit a prominent glass transition and a small melting endotherm. It is possible to model the glass transition temperature of hyperbranched polymers by adapting a method used to calculate the glass transition temperature of dendritic polymers. Because the glass transition occurs near ambient temperature, small changes in the glass transition temperature with generation number have a large effect on the mechanical properties. Polyols that are above the glass transition temperature are ductile. Polyols that are below the glass transition temperature are brittle. When deposited from a dilute solution, the polyols form monolayer aggregates of spherical molecules. The aggregates are stabilized by hydrogen bonding of terminal repeat units. The observation of a yield stress indicates that the intermolecular associations provide a level of resistance to deformation. However, because the globular structure does not permit the usual processes of orientation and strain hardening, the neck gradually thins until it fractures at an engineering strain above 100%. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1207–1217, 2000     

New aromatic–aliphatic hyperbranched polyesters with vinylic end groups of different length as modifiers of epoxy/anhydride thermosets

The synthesis and characterization of two new aromatic–aliphatic hyperbranched polyesters modified with long and short vinylic chains was reported. These hyperbranched polymers were used as toughening modifiers of epoxy/anhydride thermosets. The curing of mixtures of diglycidyl ether of bisphenol A and hexahydro-4-methylphtalic anhydride with different proportions of both hyperbranched polymers using N,N-benzyldimethylamine as catalyst was investigated by differential scanning calorimetry. The kinetic of curing process was established using an isoconversional integral procedure. The characterization of these materials was done by means of several thermal analysis techniques and their morphology was investigated by electron microscopy. The addition of highly branched structures led to homogeneous morphologies and a more toughening fracture of the thermosets in comparison to the neat epoxy/anhydride material. The modified thermosets presented slightly lower glass transition temperature than the unmodified one and the thermal stability barely changed by the addition of the modifiers.     

Synthesis and characterization of a thermotropic liquid crystalline hyperbranched polyester

BACKGROUND: Hyperbranched polymers have received increasing attention in the fields of medicine, homogeneous catalysis and materials science. Hydroxyl‐functional aliphatic polyesters are one of the most widely investigated families of hyperbranched polymers. The research reported here is based on the preparation of a novel hyperbranched polyester and the modification of its terminal hydroxyl groups by biphenyl mesogenic units. RESULTS: 2,2,6,6‐Tetramethylolcyclohexanol as a core and 8‐[4′‐propoxy(1,1‐biphenyl)yloxy]octanoic acid as a mesogenic unit were synthesized. A hyperbranched polyester (HPE) was synthesized in one step and subsequently substituted by reaction of its terminal hydroxyl groups with the biphenyl mesogenic units to yield a novel liquid crystalline hyperbranched polyester (HPE‐LC). The chemical structures of all compounds were confirmed using Fourier transform infrared, ¹H NMR and ¹³C NMR spectroscopy. The thermal behavior and the mesogenic properties of the biphenyl mesogenic unit and HPE‐LC were investigated using differential scanning calorimetry, polarized optical microscopy and wide‐angle X‐ray diffraction. The results demonstrated that the degree of branching of the HPE is ca 0.63. Both HPE‐LC and the biphenyl mesogenic unit exhibit mesomorphic properties, but HPE‐LC has a lower isotropic transition temperature and a wider transition temperature range than the biphenyl mesogenic unit. CONCLUSION: A novel liquid crystalline hyperbranched polyester was successfully synthesized, which exhibits mesomorphic properties. This polymer has good solubility in highly polar solvents and good thermal stability. Copyright © 2009 Society of Chemical Industry     

Rheology of concentrated solutions of hyperbranched polyesters

The solution rheology of different generations of hyperbranched polyesters in N‐methyl‐2‐pyrrolidinone (NMP) solvent was examined in this study. The solutions exhibited Newtonian behavior over a wide range of polyester concentrations. Also, the relative viscosities of poly(amidoamine) (PAMAM) dendrimers in ethylenediamine were compared with those of the hyperbranched polyesters in NMP. Both types of dendritic polymers have relative viscosities that are exponential functions of their molar fraction in solution. The slopes of these relative viscosity curves show a linear relationship with respect to the generation number. PAMAM dendrimers have the greater slopes for each generation, reflecting their relatively larger intrinsic viscosity values.