超支化聚(胺酯)的合成及其光固化性能研究

采用甲基丙烯酸酐直接改性和先以丁二酸酐或邻苯二甲酸酐酯化再以甲基丙烯酸缩水甘油酯改性所得到的甲基丙烯酸酯化超支化聚 (胺 酯 )齐聚物在光引发剂存在时紫外光辐照下发生快速聚合反应 ;反应速率和双键转化率随超支化分子的结构不同而变化 ;高度交联的涂膜具有较好的热学性能     

超支化树脂改性UV固化粉末涂料

本文将超支化树脂(HBP)与UV固化粉末涂料相结合,研究了超支化树脂对该涂料的树脂体系玻璃化温度、流变性能及涂膜各项物理性能的影响.结果表明:添加改性与未改性超支化树脂都能降低树脂体系的玻璃化温度,改性超支化树脂不影响体系的流变性能及涂膜性能,未改性超支化树脂可以降低体系粘度但使涂膜性能变差.     

星形超支化聚酯的合成及其光固化

紫外光固化具有快速反应、室温操作、低能消耗和无溶剂少污染等优点,现正以日益增长的速度应用于涂层和粘合剂等领域。然而,常规的线形光固化齐聚体具有缠结的柔性分子链结构,其粘度随着分子量的增大而快速增加,故其可加工性和应用受到很大的限制。     

UV‐activated hydrosilylation: a facile approach for synthesis of hyperbranched polycarbosilanes

A facile approach for synthesis of hyperbranched polycarbosilane from AB₂ monomer via UV‐activated hydrosilylation is presented in this communication. The polymerization process was monitored using real‐time FTIR spectroscopy and the resulting hyperbranched polycarbosilanes were characterized using ¹H‐NMR, ¹³C‐NMR, ²⁹Si‐NMR and SEC/MALLS. It is found that hyperbranched polycarbosilane can be synthesized from methyldiallylsilane via UV‐activated hydrosilylation with bis(acetylacetonato)platinum(II) as catalyst. The polymerization activated by UV irradiation was much faster than that under thermal conditions. The similar degree of branching, average number of branch units and the exponent of the Mark–Houwink equation demonstrate that the hyperbranched polycarbosilane synthesized via UV‐activated polyhydrosilylation possesses almost the same branching structure as that synthesized via thermal‐activated polyhydrosilylation. Copyright © 2009 John Wiley & Sons, Ltd.     

Synthesis and characterization of hyperbranched‐poly(siloxysilane)‐based polymeric photoinitiators

Three UV‐sensitive, hyperbranched‐poly(siloxysilane)‐based polymeric photoinitiators, bearing an alkyl phenone moiety linked to the surface of the hyperbranched polymer, were synthesized via the hydrosilylation of hyperbranched poly(siloxysilane) and modified UV‐sensitive compounds. Hyperbranched poly(siloxysilane) was prepared via the polyhydrosilylation of the AB₂‐type monomer methylvinyldichlorosilane. The chemical structures of the polymeric photoinitiators were characterized with ¹H, ¹³C, and ²⁹Si NMR, elemental analysis, Fourier transform infrared, differential scanning calorimetry, UV spectrophotometry, and thermogravimetric analysis. The UV‐curing behaviors of the blends of the hyperbranched polymeric photoinitiators with UV‐curable epoxy acrylate (EA) resin were determined by Fourier transform infrared, and the results showed that the initiation efficiency of the polymeric photoinitiators was excellent and that the thermostability of the EA/polymeric photoinitiator curing systems was higher than that of the EA/photoinitiators. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3261–3270, 2006     

具有可控温敏相变行为的四氢呋喃-缩水甘油超支化共聚醚的合成

采用四氢呋喃(THF)和缩水甘油(glycidol)进行阳离子开环共聚,一步合成了主链中含有柔性聚四氢呋喃线型链段的温敏性超支化共聚醚.采用定量13C-NMR确定了共聚醚的超支化结构,同时计算了其支化度.利用体积排除色谱-多角度激光光散射(SEC-MALLS)对聚合物分子量及分布进行了表征.紫外-可见光光谱(UV)测试发现共聚醚水溶液透过率在最低临界溶解温度(LCST)附近呈现剧烈变化,但是其相变速率缓慢,相变平衡时间可达30 min;且聚合物溶液的相变速率和紫外光透过率变化具有温度依赖性.采用透射电镜(TEM)对相变过程观察后发现,这种缓慢相变过程是由于超支化共聚醚组装形成的胶束随温度升高发生不同程度聚集所致.     

Using hyperbranched macromers as crosslinkers of methacrylic networks prepared by photopolymerization

Hyperbranched polymers were modified with terminal methacryloyl groups to be used as crosslinkers. The photoinitiated polymerization of several methacrylic monomers was examined in the presence of the hyperbranched macromers and bis-(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (Irgacure 819^®) as a photoinitiator, upon UV irradiation. The photopolymerization kinetics was systematically studied by fluorescence and photoDSC in real time and in situ. Six types of monofunctional methacrylic monomers, two types of difunctional methacrylic monomers and four types of (meth)acrylate-modified hyperbranched macromers with different structures were employed for series of photopolymerization reactions. The incorporation of the hyperbranched macromers allows to increase the conversion at gelation and thus, final conversion. This behaviour is dependent on monomer and macromer nature and has been explained as due to an increase of the free volume fraction and confirmed by fluorescence. The results indicate that H-bonding and π-stacking induce self-assembly of hyperbranched macromers leading to reaction induced phase separation at the highest concentration of hyperbranched macromer used.     

Synthesis of thioether derivatives of hyperbranched carbosilane polymer

Novel hyperbranched functional and non-functional carbosilane polymers bearing the thioether groups were synthesized. Thioether derivatives were prepared by the UV initiated hydrothiolation of the hyperbranched poly(allyl)carbosilane polymer with 1-decanethiol and 3-mercaptopropyl(methyl)dimethoxysilane.     

Reversible photoswitching self-assembly of azobenzene-functionalized hyperbranched polyglycerol induced by host-guest chemistry

Reversible assembly and disassembly of rod-like large complex micelles have been achieved by applying photoswitching of supramolecular inclusion and exclusion of azobenzene-functionalized hyperbranched polyglycerol and α-cyclodextrin as driving force, promising a versatile system for self-assembly switched by light. Hydrogen-nuclear magnetic resonance (1H NMR) and Fourier transform infrared (FT-IR) spectroscopy were applied to characterize the azobenzene-functionalized hyperbranched polyglycerol. Atomic force microscopy (AFM), transmission electron microscopy (TEM) and dynamic laser light scattering (DLS) were employed to investigate and track the morphology of the rod-like large complex micelles before and after irradiation of UV light.     

UV固化超支化聚酯树脂的制备研究

以双季戊四醇（DPE）为超支化核心，与偏苯三酸酐（TMA）和甲基丙烯酸缩水甘油酯（GMA）反应合成了超支化聚酯树脂。偏苯三酸酐半酯化后产生羧基，羧基再与GMA中的环氧基反应提供UV固化性能。同时研究了温度、催化剂等因素对反应的影响。     

Synthesis and characterization of highly stable blue‐light‐emitting hyperbranched conjugated polymers

Polyfluorene homopolymer ( P1 ) and its carbazole derivatives ( P2 – P4 ) have been prepared with good yield by Suzuki coupling polymerization. P2 is an alternating copolymer based on fluorene and carbazole; P3 is a hyperbranched polymer with carbazole derivative as the core and polyfluorene as the long arms; P4 is a hyperbranched polymer with carbazole derivative as the core and the alternating fluorene and carbazole as the long arms. These polymers show highly thermal stability, and their structures and physical properties are studied using gel permeation chromatography, ¹H NMR, ¹³C NMR, elemental analysis, Fourier transform infrared spectroscopy, thermogravimetry, UV–vis absorption, photoluminescence, and cyclic voltammetry (CV). The influence of the incorporation of carbazole and the hyperbranched structures on the thermal, electrochemical, and electroluminescent properties has been investigated. Both carbazole addition and the hyperbranched structure increase the thermal and photoluminescent stability. The CV shows an increase of the HOMO energy levels for the derivatives, compared with polyfluorene homopolymer ( P1 ). The EL devices fabricated by these polymers exhibit pure blue‐light‐emitting with negligible low‐energy emission bands, indicating that the hyperbranched structure has a strong effect on the PLED characteristics. The results imply that incorporating carbazole into polyfluorene to form a hyperbranched structure is an efficient way to obtain highly stable blue‐light‐emitting conjugated polymers, and it is possible to adjust the property of light‐emitting polymers by the amount of carbazole derivative incorporated into the polymers. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 790–802, 2008     

可光固化星形超支化聚酯的合成与表征

描述了基于季戊四醇和１，２，４ 苯三甲酸酐，经由甲基丙烯酸缩水甘油酯和甲基丙烯酸酐改性的系列超支化聚酯的“发散”合成方法，即合成反应从“中心核”开始，逐步向外扩展，控制链增长，每个分子形成具有大约８，１２和１６个甲基丙烯酸酯双键的超支化臂。这种星形聚酯分子具有三维球状结构，不会产生分子链间的缠结，在辐射固化涂层和粘合剂等领域具有广阔的应用前景．     

Effect of molecular architecture and size of mesogen on phase behavior and photoactive properties of photoactive liquid crystalline hyperbranched polyester epoxies containing benzylidene moiety

A series of photoactive liquid crystalline linear and hyperbranched polyester epoxies were synthesized by polyaddition of photoactive bis benzylidene alkanone diol monomers and terephthalic acid and trimesic acid respectively with good yield. The effect of molecular architecture (linear and hyperbranched), size of mesogenic unit (cyclic and acyclic units) on the physicochemical, thermal, mesogenic, and photoactive properties of hyperbranched polymers were studied and compared. Degree of branching of hyperbranched polymers was found to be in the range of 0.46–0.49. Monomers containing cyclic moieties only exhibited nematic mesophase, while all polymers exhibited typical nematic mesophase. Intermolecular photo cycloaddition reaction was studied by ultraviolet–visible spectra (UV–vis) and NMR spectroscopy and photo viscosity measurement of UV irradiated polymer solutions. Faster photo induced behavior of hyperbranched polymers containing acyclic alkanone moiety, as compared to polymers containing cycloalkanone moieties, was observed. The change in the refractive index was found to be in the range of 0.02–0.024. Substantial variation of refractive index indicates that this polymer could be used for optical recording. All the polymers were also found to be fluorescent in nature. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 552–563, 2008     

Synthesis and properties of UV curable waterborne hyperbranched aliphatic polyester

The UV curable waterborne hyperbranched polyester (WBHP) consisting of a multi-hydroxy functional aliphatic polyester core, which is endcapped with methacrylic and salt-like groups in different ratios was synthesized. The core is second generation of hyperbranched aliphatic polyester Boltorn™ H20 with approximately 16 hydroxyl groups. The effects of different ratios of chemical structure of end groups were studied by evaluating various properties of WBHP such as solubility in water, dynamic viscosity, UV curing rate and final unsaturation conversion. A natural good control over the solubility of the samples was possible by salt-like functionality and raising the temperature. The investigation of solubility characteristics of the modified hyperbranched polyester illustrated that those with higher concentration of salt-like moiety were more soluble while those of having lower salt-like moiety were less soluble. The viscosity of the resin WBHP was reduced rapidly by dilution with water and raising temperature. Water showed a favorable viscosity reduction effect as compared to monomer and its blend with water. The polymerization rate of the resins under UV irradiation in the presence of a photoinitiator showed an increasing trend with higher concentration of methacrylate functionality.     

Nanopattern formation on polymer substrate using star-hyperbranched nanospheres

Hyperbranched polystyrenes (PS) were prepared by living radical photopolymerization of 4-vinylbenzyl N,N-diethyldithiocarbamate as an inimer under UV irradiation. These hyperbranched PS exhibited large amounts of photofunctional dithiocarbamate groups on their outside surfaces. Subsequently, we derived the star-hyperbranched copolymers by grafting from hyperbranched macroinitiator with t-butyl methacrylate. We obtained poly(methacrylic acid) star-hyperbranched PS nanospheres by hydrolysis of poly(t-butyl methacrylate) grafted chains. We studied in detail two-dimensional nanopattern formation on poly(4-vinylpyridine) (P4VP) or partially quaternized P4VP substrate using such nanospheres by electrostatic interaction.     

一种超支化聚硅烷的合成和性能

近年来,光电高分子的研究由于其在发光二极管、太阳能电池、光信息材料、传感器等方面的潜在应用而得到了广泛重视[1].自从英国剑桥大学Cavendish实验室的Burroughes等首次发现聚对亚苯基亚乙烯基的电致发光现象以来[2],共轭聚合物作为发光材料的研究迅速引起了人们的注意[3~5]     

超支化聚酯的改性及其结晶性能的研究

用十六酰氯和十八异氰酸酯分别对端羟基的超支化聚酯Boltorn^TMH20改性,可获得粉末状超支化低聚物,具有无定形“内核”及可结晶“外壳”的分子结构.实验结果表明,采用十八异氰酸酯改性的丙烯酸化超支化聚酯的熔点高于十六酰氯改性聚合物.     

Free Radical Scavenging Magnetic Iron-Based Nanoparticles in Hyperbranched and Linear Polymer Matrices

Magnetic iron nanoparticles are attracting a great deal of research and application interest in diversified fields. In this present investigation, iron nanoparticles were prepared by a in-situ chemical reduction technique in a combination of polyaniline (PANI)-polyacrylamide (PA) and PANI-hyperbranched polyurethane (HBPU) matrices to judge the suitability of hyperbranched system. The formation of the nanoparticles in polymer matrices has been investigated by FTIR, UV, XRD, SEM and TEM studies. Narrower size with better dispersion and more stable nanoparticles were found in a hyperbranched matrix system compared to a linear one. The particle size was found to be in the range of 10–20 nm and 12–35 nm in HBPU-PANI and PA-PANI matrices, respectively. Both the nanocomposites exhibit synergistic free radical scavenging capability towards 2,2-diphenyl-1-picrylhydrazyl (DPPH). The magnetic hysteresis loop of the nanocomposites indicates the super-paramagnetic behavior. The hyperbranched system is more thermostable than the linear system by 70°C.     

Synthesis and characterization of hyperbranched polymers with increased chemical versatility for imprint lithographic resists

Hyperbranched polymers were prepared from a variety of mono‐ and difunctional monomers and used in the development of novel UV‐imprint lithography (UV‐IL) resists. The unique physical and chemical properties of these hyperbranched materials significantly increase the range of molecular systems that could be imprinted. Traditional challenges, such as the use of monomers that have low boiling points or the use of insoluble/highly crystalline momomers, are overcome by the preparation of hyperbranched polymers that incorporate these repeat units. In addition, the low viscosity of the hyperbranched macromolecules and the large number of reactive chain ends overcome many difficulties that are traditionally associated with the use of polymeric materials as imprint resists. Hyperbranched polymers containing up to 12 mol % pendant vinyl groups, needed for secondary crosslinking during imprinting, were prepared with a wide range of repeat unit structures and successfully imprinted with features from tens of microns to ∼ 100 nm. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6238–6254, 2008     

Thermal studies and chromium removal efficiency of thermoresponsive hyperbranched copolymers based on PEG-methacrylates

This study deals with the removal of chromium species from aqueous dilute solutions using thermoresponsive linear and hyperbranched copolymers based on PEG-methacrylates. The thermal stability of polymers was studied by thermogravimetric analysis and chemiluminescence emission, which evidenced a slightly enhanced stability for hyperbranched polymers respect to linear structures. Their LCST was successfully determined by TOPEM (temperature-modulated DSC), and similar values to those obtained by UV spectroscopy were obtained. The adsorption capacities for chromium hexavalent of the polymers have been investigated as function of LCST. The results showed highest retention capacity of Cr(VI) for all polymers above LCST. Hyperbranched polymers were more efficient than linear polymers, because of the structure of the polymers. Hyperbranched polymers when precipitate form a network with more nanocavities where the chromium can be adsorbed. The efficiency increased with ratio of OEGMA/DEGMA, reaching a maximum retention capacity value of 40 mg Cr(VI)/g polymer.