含氟丙烯酸酯光致聚合物的全息特性研究

提高记录单体在成膜物中的迁移速率,加大记录单体与成膜物的折射率差,可以实现光致聚合物的折射率空间调制最大化.本工作以高折射率的超支化聚酯(折射率1.586)为成膜树脂,利用超支化聚合物分子结构疏松、便于小分子在其间扩散的特性,同时以低折射率的单官能团含氟丙烯酸酯(折射率1.372)和高活性的双官能团丙烯酸酯(折射率1.457)为记录单体制备了光致聚合物全息膜,以衍射效率为指标优化单体构成和全息膜的厚度,研究了该全息膜的衍射效率、空间分辨率、折射率调制度等性能.该光致聚合物全息材料的折射率调制度为4.82×10-3,衍射效率达到99.4%,在空间分辨率3750 lp/mm的衍射效率仍然达到85.6%,感光灵敏度56 mJ/cm2.     

超支化聚酯的合成与封端改性研究

以偏苯三酸酐(TMA)、环氧氯丙烷(ECH)为原料,在四丁基溴化铵(TBAB)催化作用下,通过酸值跟踪法合成了末端全羟型超支化聚酯,并分别以苯甲酸、苯甲酰氯为封端改性剂对其进行封端改性研究。结果显示:通过酐值对分子量的研究,发现采用高酐值酸酐有利于生成大分子量的全羟型超支化聚酯;苯甲酰氯的封端效率高于苯甲酸且工艺更简单。     

超支化聚芳酰胺合成及表征

由3,5-二硝基苯甲酰氯和间氨基苯甲酸合成了一种超支化AB2型单体3-(3,5-二氨基苯甲酰氨基)苯甲酸,该单体进行自缩聚反应,合成了新型超支化聚酰胺(a),将其与酰氯反应,制得7种封端超支化聚合物(b￣h)。所得聚合物通过红外光谱(FT-IR)、核磁共振(1H-NMR)和差示扫描量热法(DSC)等进行了表征。聚合物a￣h的特性黏度为0.063￣0.077dL/g,玻璃化转变温度(Tg)为54￣188℃。聚合物b￣d的Tg随封端剂脂肪链增长而降低,聚合物e￣h的Tg随封端剂极性增加而升高。封端改性后,聚酰胺的溶解性得到了不同程度的改善。     

光致聚合物材料中各组分对光聚合速度的影响及其在全息存储中的应用实验

本文研究了光敏剂、光引发剂、光促进剂、单体及高分子成膜树脂等成份对全息光致聚合物薄膜光存储性能的影响，在一定范围内，材料中光引发剂浓度的提高使光聚合速度显著增加，链转移剂浓度则存在一个最佳的相对浓度，适当地增加液态辅助单体含量及其所含双键官能团的数目，会明显增加光聚合速度，在聚醋酸乙烯酯薄膜中单体聚合速度明显优于在醋酸纤维素中的速度，所制备的光致聚合物材料实现了同一位置的多幅全息图像的存储和再现，表明了该材料有用于大容量全息存储的可能。     

核分子比例对超支化聚酯结构和涂膜性能的影响

以双季戊四醇为核,二羟甲基丙酸为单体合成了不同代数的超支化聚酯。采用了IR、GPC、13C NMR、DSC和化学滴定等方法对产物进行了表征和分析。试验结果表明聚合物具有较小的多分散性指数(拟两代超支化聚酯M—w/M—n=1.159,拟四代超支化聚酯M—w/M—n=1.028)。通过聚合物的13C NMR分析了超支化聚酯的支化度,表明在超支化聚酯中,端羟基的反应活性大于线性单元中羟基的活性。并用油酸对聚合物进行改性,研究了固含量与黏度的关系及其涂膜的性能;结果表明该树脂具有良好的成膜性和涂膜性能。     

超支化聚酯的改性及其在牙科修复树脂中的应用

以季戊四醇(B4单体)为核,2,2-二羟甲基丙酸(AB2单体)为单体,对甲苯磺酸为催化剂,通过熔融缩聚反应合成末端为16个羟基的二代Boltorn型超支化聚酯HBP。并进一步用甲基丙烯酰氯、丙酰氯对端羟基进行改性,在HBP末端全部引入双键或部分引入双键,得改性后超支化聚酯GHBP1和GHBP2。在传统牙科修复树脂双酚A甲基丙烯酸缩水甘油酯(Bis-GMA)和二甲基丙烯酸三甘醇酯(TEGDMA)的混合体系中引入不同质量分数的GHBP,考察其对树脂收缩率和双键转化率的影响。结果表明,GHBP改性牙科修复树脂后,树脂的聚合收缩明显降低,且GHBP2具有更优异的减小收缩的性能,但双键转化率无明显变化。     

新型涂料用超支化聚酯酰胺聚合物的应用研究

以六氢苯酐和含氮二元醇为原料,合成了AB2单体和超支化聚酯酰胺聚合物。采用FT-IR、DSC-50、GC/MS和化学滴定等方法对得到的单体和聚合物的结构分别进行了表征和分析。实验表明合成的超支化聚合物是非结晶的,其玻璃化转变温度为67℃;聚合物的数均相对分子质量为1 689.04～3 752.6。进一步用油酸对聚合物进行改性,并研究油改性树脂溶液的流变性和以聚氨酯为固化剂配制成的涂料的涂层性能,结果表明该涂料在室温下快速固化,得到的涂层具有良好的涂膜性能。     

一种用于喷墨墨水的超支化聚合染料的合成研究(英文)

本论文采用一步法,以季戊四醇作为B4核单体、2,2-二羟甲基丙酸作AB2型单体合成了超支化聚酯内核(HBPE),并对产物进行表征,计算超支化聚酯的支化度为0.41;探讨并建立了超支化聚酯的缩聚反应动力学方程-d[COOH]/dt=K[COOH][OH],该缩聚反应属于二级反应,反应速率由羧基浓度和羟基浓度共同决定。采用月桂酸改性超支化聚酯合成了新的长链烷基化的超支化聚合物(LHBP),并用红外和核磁共振谱图进行结构表征。溶解性质表明月桂酸改性超支化聚酯溶解于极性较弱的溶剂中,较未改性的超支化聚酯具有更好的有机溶剂溶解性。采用改性后的超支化聚酯内核(LHBP)和2-羟乙胺基蒽醌,通过IPDI偶联法合成了超支化聚合染料(R-LHBP)。     

超支化聚(酰胺-酯)的合成与改性

以邻苯二甲酸酐和二乙醇胺为原料,制得AB2型单体;加入三羟甲基丙烷为核,采用一步法合成了超支化聚(酰胺-酯),并用硬脂酸对所得聚合物进行封端改性.应用红外光谱对改性前后超支化聚合物进行了表征.结果表明,所合成的聚合物与理论结构相吻合,且硬脂酸与端羟基发生了酯化反应,成功地接到了聚合物上.     

超支化聚合物在天然植物纤维复合材料中的应用研究

介绍了超支化聚合物在天然植物纤维表面改性中的研究情况,包括端羧基超支化聚酯和端氨基超支化聚酰胺胺。总结了超支化聚合物改性在树脂/植物纤维复合材料中的应用研究进展,并重点对改性后复合材料的力学性能进行了详细阐述。     

碱性品红光敏感的新型光致聚合物全息存储材料

本文制备了一种以碱性品红为光敏剂的新型全息存储材料,且使用波长为532nm的半导体激光器成功研究了材料的全息特性。研究表明,该材料具有较高的衍射效率、曝光灵敏度和较大的折射率调制度,衍射效率近40%,灵敏度为8.38×10-4cm2/mJ,折射率调制度为4.5×10-4。在存储介质膜中存储了全息图像,再现图像较为清晰,对比度与保真度较为理想,说明该材料具有较好的全息存储性能,适合作为高密度全息存储介质。     

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     

High performance holographic gratings formed with novel photopolymer films containing hyper-branched silsesquioxane

A transparent photopolymer film was prepared by embedding the epoxy cured octaaminophenylsilsesquioxane (hyper-branched POSS) into poly(vinyl chloride) (PVC) matrix containing vinyl monomers. Holographic gratings were successfully generated in that films by irradiation of laser light with 532 nm wavelength.The diffraction efficiency was increased with increasing the hyper-branched POSS concentration up to 15 wt%. DSC and TG analysis indicated the plasticizing effect of POSS in photopolymer that loosened the polymer matrix. This plasticizing effect made the monomer diffusion much more effective providing higher diffraction efficiency (D.E. ∼ 80%) compared to the film without hyper-branched POSS (D.E. ∼ 50%). The diffraction efficiency started to decrease with further higher concentration of POSS, because the polymer film became less transparent.Low volume shrinkage of 1.64% could be also obtained in recording of slanted holographic gratings.     

Polymer holography I – Method and experiment

Summary Processes of radical photopolymerization running during the holographic exposition in photopolymer recording materials are investigated. Special experimental setup, which makes recording and continuous measuring of the forming hologram possible, was built up. An acrylamide-based recording material was prepared and tested. Our experiments verified that addition of bis-acrylamide improves the stability of the hologram due to micronetwork formation.     

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。     

A novel dry photopolymer for volume‐phase holograms

A novel photopolymer for the fabrication of high‐resolution volume‐phase holograms, which primarily are used for holographic optical elements, is reported. This photopolymer consists of a thermosetting resin as a polymeric binder, a polyfunctional monomer, a photoinitiator, and a sensitizing dye. The chemistry to form images is based on the polymerization of an acrylic monomer initiated by radical species while making the holographic exposure, and accelerated diffusion transfer of the polymerized monomer with postexposure baking, and of a bisphenol‐type epoxy resin as a binder initiated by cations with UV exposure, which are generated through photodecomposition of a diaryliodonium salt‐sensitized 3‐ketocoumarin dye. Exposure of these photopolymer films to an Ar⁺ laser beam emitting 514.5 nm light at 60–150 mJ/cm² and subsequent heat treatment resulted in a refractive index alteration according to the light intensity. With this dry process, high diffraction efficiency and heat‐stable holograms can be formed. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2189–2200, 2000     

Flame retardant epoxy resins from bisphenol-A epoxy cured with hyperbranched polyphosphate ester

A novel hyperbranched polyphosphate ester (HPE) was synthesized via the polycondensation of bisphenol-A and phosphoryl trichloride. The formed HPE was characterized by FTIR, ¹H NMR and ³¹P NMR to confirm its structure. Then, a series flame retardant epoxy resins from bisphenol-A epoxy cured with HPE and bisphenol-A were prepared. The combustion behavior of the flame retardant epoxy resins was studied using limiting oxygen index (LOI) and cone calorimeter test. The LOI value increased from 23 to 32 when HPE, instead of bisphenol-A, was used as a curing agent. The cone calorimeter test data revealed that the cured bisphenol-A epoxy resin with HPE as a curing agent possessed improved flame retardancy. The photo graphs and scanning electron microscopy (SEM) of char residues confirmed the cone calorimeter results.     

A study on the preparation of polymer/montmorillonite nano‐composite materials by photo‐polymerization

The preparation of polymer/montmorillonite intercalation composite materials was studied by two kinds of photo‐polymerization reaction (photo‐acid generation and photo‐radical generation). Small‐angle X‐ray diffraction was used for the structural characterization of montmorillonite contained in the products. Results indicated that, after chemical modification of montmorillonite, the monomer (methyl methacrylate) and the prepolymer (m‐cresol/HMMM) were able to intercalate into the layers of clay and to polymerize ‘in situ’, thus producing photo‐polymerized composite materials. The advantages and shortcomings of the method of photo‐polymerization for the preparation of these composite materials are discussed. © 2001 Society of Chemical Industry