用于公路工程的聚氨酯密封胶研究进展

本文主要归纳了聚氨酯材料作为路用密封胶的研究进展,包含聚氨酯密封材料的概述及反应机理、主要组成材料（多异氰酸酯、多元醇、扩链交联剂、催化剂以及填料等）、性能评价（宏观、微观、分子动力学模拟等）、新型聚氨酯密封胶种类（如改性聚氨酯密封胶、生物基聚氨酯密封胶、无溶剂聚氨酯密封胶等）,并概述了聚氨酯密封胶在公路工程中的实际应用情况。最后,提出了目前聚氨酯密封胶研究中存在的问题,并对发展趋势进行了展望。     

文献题录

聚氨酯文献题录（三十八） 聚氨酯硬泡改性研究的新进展．化学推进剂与高分子材料，2008，6（4）：6—10． 聚氨酯中游离-NCO含量的测定．化学推进剂与高分子材料，2008，6（4）：16—19． 醇酯型聚氨酯油墨连接料的研制.化学推进剂与高分子材料，2008，6（4）：20—22．     

沥青面层聚氨酯修复材料与修复实验研究

我国沥青混凝土路面早期损失病害以路面裂缝为主,高分子面层修复材料具有良好的裂缝修复功能。基于此,制备了由聚氨酯、环氧丙烯聚酯、2,4-二甲基苯胺、1,4-丁二醇、过氧化苯甲酰组成的沥青面层修复材料,开展室内实验,分析了聚氨酯掺比对沥青面层修复材料抗压强度、耐老化性、水稳定性以及低温性能测试的影响规律,给出了最佳聚氨酯掺比。研究结果表明,（1）沥青面层修复材料的抗压强度随着聚氨酯掺比的增大而减小;（2）沥青面层修复材料的抗拉强度随老化时间的增加而降低;（3）从沥青面层修复材料的水稳定性、低温特性角度来看,最佳聚氨酯掺比为24%。     

聚氨酯材料

聚氨酯材料应用在汽车装饰方面的新一代ＲＩＭ（反应注压成型）聚氨酯材料现已问世。这些产品以有成本竞争性的包装可提供各种性能特性的普通ＲＲＩＭ（补强反应注压成型）聚氨酯胶料。该公司通过在材料和加工的三方面改性普通ＲＩＭ聚氨酯而开发这种材料。这种改性包括较...     

异氰酸酯市场需求展望

聚氨酯（PU）为世界六大具有发展前途的合成材料之一，异氰酸酯TDI（甲基二异氰酸酯）和MDI（二苯甲烷二异氰酸酯）是生产聚氨酯的首要原料，以不同原料TDI，MDI生产的各类聚氨酯材料广泛应用于生产汽车零部件，鞋底，人造革，涂料，胶粘剂，隔热材料等。     

开发可降解聚氨酯材料前景广阔

可降解聚氨酯材料在医用、包装等许多领域具有广阔的应用前景，成为世界各国的研究开发热点。可降解聚氨酯的合成方法按时间顺序和技术发展程度，可分为：（1）与天然物质共混；（2）改性后共混；（3）与天然物质共聚；（4）分子链设计。用前三种传统方法合成可降解聚氨酯材料，工艺较简便且成本较低，缺点是不能彻底降解，只能部分降解。用第四种方法通过分子链设计合成的可降解聚氨酯材料能够彻底降解，     

聚氨酯增韧环氧灌封材料的制备与表征

以异氰酸酯封端的聚氨酯预聚体（PU）与环氧树脂（EP）发生反应,制备了聚氨酯接枝改性环氧灌封材料。FTIR表明异氰酸酯封端的聚氨酯预聚体与环氧树脂中的仲羟基完全反应,同时考察了活性稀释剂用量对树脂黏度的影响及固化过程中温度的变化。聚氨酯预聚体的加入,使材料的冲击强度和弯曲强度都有所升高,当聚氨酯质量分数为5％时,材料的弯曲强度提高了30%,而冲击强度提高了近200%,玻璃化转变温度没有降低,SEM分析了其增韧机理。     

聚氨酯材料结构的现代分析技术联用解析

以未知结构的聚氨酯预聚体为研究对象,介绍了裂解气相色谱-质谱（Py—GC／MS）、凝胶渗透色谱（GPC）、核磁共振碳谱（^13C-NMR）和红外光谱（FT-IR）等现代分析技术联用在聚氨酯材料结构分析中的应用。     

脂肪族聚碳酸酯型聚氨酯互穿网络聚合物的研究

简述了脂肪族聚碳酸酯聚氨酯（ＰＣＵ）互穿网络聚合物（ＩＰＮ）的发展及最新研究动态。介绍了其制备、表征、结构与性能的关系。预示了聚碳酸酯型聚氨酯互穿网络聚合物材料的开发前景。     

三阶非线性光学材料聚氨酯-酰亚胺的合成研究

以甲苯-2,4-二异氰酸酯（TDI）和分散红-19（DR-19）合成含染料发色团的聚氨酯,进一步和二酐单体均苯四甲酸二酐（PMDA）缩合生成具有光学性能的聚氨酯-酰亚胺（PUI）;采用红外光谱（FT—IR）、示差量热扫描（DSC）、热失重分析（TGA）等手段对合成的PUI进行了表征。示差扫描量热和热失重分析结果显示,其玻璃化转变温度（％）为194℃,在5％的热失重温度为217℃,表明具有很好的热稳定性;测定了聚合物的发色团密度,其结果和理论计算值非常接近,表明聚合反应是按计量进行的;采用简单的比色法测定了聚合物材料的三阶非线性光学系数Х^（3）为2．42×10^14esu。     

无机-有机杂化二阶非线性光学材料研究进展

二阶非线性光学(nonlinera optics,NLO)材料在电光调制和激光倍频等光电子领域均具有重要应用无机-有机杂化材料兼具有机组分和无机组分的优点,具有较高的NLO系数以及良好的高温和经时稳定性,是该领域的研究热点.本文重点评述了该类材料在NLO性能的改善和稳定性的提高等方面的研究进展,对近年来基于杂化材料的Maeh-Zehnder电光调制器的最新研究成果作了概述.提出采用超支化结构有望提高杂化材料的相容性,实现光学非线性、稳定性以及成膜性的综合优化,将是今后发展的重要方向.     

Synthesis and nonlinear optical properties of a novel polyurethane containing cyanovinylthiophene with enhanced thermal stability of dipole alignment for electro‐optic applications

Stabilization of electrically induced dipole alignment is one of the important criteria in the development of nonlinear optical (NLO) polymers for electro‐optic device applications. Polyurethanes for NLO applications have attracted attention because of their high thermal stability due to hydrogen bonding. In the work reported here, we designed and synthesized a new type of NLO polyurethane, in which the pendant NLO chromophores are part of the polymer backbone. This mid‐type NLO polymer is expected to have the merits of both main‐chain and side‐chain NLO polymers, namely stable dipole alignment and good solubility. 1‐[3,4‐Di‐(2‐hydroxyethoxy)phenyl]‐2‐(2‐thienyl)ethene was prepared and condensed with 3,3′‐dimethoxy‐4,4′‐biphenylenediisocyanate to yield a polyurethane. This polyurethane was reacted with tetracyanoethylene to give a novel Y‐type polyurethane (7) containing 1‐(3,4‐dioxyphenyl)‐2‐[5‐(1,2,2‐tricyanovinyl)‐2‐thienyl]ethenes as NLO chromophores, which constitute part of the polymer backbone. Polyurethane 7 is soluble in common organic solvents such as N,N‐dimethylformamide and dimethylsulfoxide. It shows a thermal stability up to 280 °C from thermogravimetric analysis with a glass transition temperature obtained from differential scanning calorimetry of ca 162 °C. The second harmonic generation (SHG) coefficient (d₃₃) of a poled polymer film of he polyurethane at 1560 nm fundamental wavelength is ca 1.11 × 10^?18 C. Polymer 7 exhibits an enhanced thermal stability and no significant SHG decay is observed below 150 °C, which is acceptable for NLO device applications. Copyright © 2009 Society of Chemical Industry     

Thermally stable interpenetrating polymer networks for second‐order nonlinear optical materials

We report several kinds of interpenetrating polymer networks (IPNs) with nonlinear optical (NLO) properties. DMA spectra show that the two components of the IPNs have good compatibility with each other. The NLO materials have good optical transparency. The thermal stability of alignment was improved and the poled order remained very high. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 7–9, 1999     

配位聚合物的研究进展

综述了近年来比较热门的研究领域——配位聚合物,它是由过渡金属和有机配体自组装而形成的,具有独特的空间几何构型,在非线性光学材料、磁性材料、超导材料,微孔材料及非对称催化等诸多方面都有广阔的应用前景。本文就不同配体的配位聚合物进行了分类研究。     

New crosslinked polymer systems with high and stable optical nonlinearity

Thermo-crosslinkable copolymers (PGMAA and PGMAS) of glycidyl methacrylate containing azobenzene chromophores (20 mol%) and stilbene chromophores (19 mol%) respectively were synthesized and characterized. In order to obtain crosslinked polymers with high and stable second-order nonlinear optical (NLO) property, PGMAA and PGMAS were doped with a reactive nonlinear optical (NLO) dye, 4-nitro-4′-aminobiphenyl (20 mol% of the glydidyl group). In the poled state, these doped polymers systems (PGMAD and PGMSD) can be thermo-crosslinked to yield materials with high second-order (NLO) coefficient (d₃₃) of 4.33×10⁻⁷ esu and 4.74×10⁻⁷ esu respectively. The investigation of SHG decay at room temperature and 100°C showed that the polymer networks much improved the SHG stability.     

Synthesis and electro‐optic properties of novel polyurethane containing the nitrophenylazoresorcinoxy group

A novel Y‐type polyurethane (polyurethane 3) containing 4‐(4‐nitrophenylazo)resorcinoxy groups as nonlinear optical (NLO) chromophores, which constitute part of the polymer backbone, was prepared and characterized. Polyurethane 3 is soluble in common organic solvents such as acetone and N,N‐dimethylformamide. It shows thermal stability up to 270 °C from thermogravimetric analysis with a glass transition temperature obtained from differential scanning calorimetry of 102 °C. The second harmonic generation (SHG) coefficient (d₃₃) of the poled polymer film at 1064 nm fundamental wavelength is 2.06 pm V^?1. Polymer 3 exhibits thermal stability up to T_g, and no significant SHG decay is observed below 100 °C, which is acceptable for nonlinear optical device applications. Copyright © 2012 Society of Chemical Industry     

Novel crosslinked nonlinear optical materials based on cellulose diacetate

Preparation of second‐order nonlinear optical (NLO) materials based on cellulose diacetate and melamine derivatives was attempted. The NLO chromophore DR19 was incorporated into the crosslinking network resulting from the reaction of cellulose diacetate with trimethylolmelamine or hexamethylolmelamine. The poled and cured NLO materials exhibited electrooptic coefficient (r₁₃) values of 1.11 or 1.03 pm/V, respectively, at a laser wavelength of 1550 nm, a modulation frequency of 12.7 kHz. The r₁₃ values decreased to 80 or 81.5% of the initial values after 4 days. The laser transmission loss was 0.50 or 0.44 db. The crosslinking materials showed better temporal stability than that of host/guest type materials, and 73% of the initial r₁₃ value remained after keeping the NLO film at 100°C for 15 h. No evident weight loss was found below 250°C. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2832–2837, 2006     

Synthesis,characterization and non-linear optical response of organophilic carbon dots

For the first time ever we report the nonlinear optical (NLO) properties of carbon dots (C-dots). The C-dots for these experiments were synthesized by mild pyrolysis of lauryl gallate. The resulting C-dots bear lauryl chains and, hence, are highly dispersible in polar organic solvents, like chloroform. Dispersions in CHCl₃ show significant NLO response. Specifically, the C-dots show negative nonlinear absorption coefficient and negative nonlinear refraction. Using suspensions with different concentrations these parameters are quantified and compared to those of fullerene a well-known carbon molecule with proven NLO response.     

The role of introduced isolation groups in PVK-based nonlinear optical polymers: Enlarged nonlinearity, improved processibility, and enhanced thermal stability

In this paper, a new series of PVK-based nonlinear optical (NLO) polymers were successfully synthesized, in which different isolation moieties (from the small to large size) were bonded to the NLO chromophore moieties. All the polymers were well characterized, and the obtained results demonstrated that the polymers exhibited improved solubility and processibility, and good optical transparency upon the introduction of the isolation groups, in addition to the enhanced NLO effects, further confirming that the linkage of isolation groups will not only boost the NLO properties of the resultant polymers to possibly high values, but also improve their processibility during the device manipulation process.