高透紫外线高分子材料的研究进展

随着光学、生物、电子、军事等领域对材料的透紫外性要求越来越高,高透紫外高分子材料的应用范围也越来越广。文中综述了含氟聚酰亚胺、无定型含氟聚合物、丙烯酸酯类聚合物、环氧树脂类聚合物、有机硅聚合物等5种高透紫外线材料的制备方法,聚合物结构对紫外透过率的影响以及在光学行业,电子工业上的应用,并展望了高透紫外线高分子材料的研究方向和应用前景。     

高透紫外线高分子材料的研究进展EI北大核心CSCD

随着光学、生物、电子、军事等领域对材料的透紫外性要求越来越高,高透紫外高分子材料的应用范围也越来越广。文中综述了含氟聚酰亚胺、无定型含氟聚合物、丙烯酸酯类聚合物、环氧树脂类聚合物、有机硅聚合物等5种高透紫外线材料的制备方法,聚合物结构对紫外透过率的影响以及在光学行业,电子工业上的应用,并展望了高透紫外线高分子材料的研究方向和应用前景。     

含氟丙烯酸酯单体的合成及固化膜的性能

以六氟环氧丙烷低聚物和(甲基)丙烯酸-β-羟乙酯为起始原料,合成了(甲基)丙烯酸-β-(全氟烷氧基酰基)乙酯四种新型含氟单体,其结构经红外光谱(FT-IR)、核磁共振(1H-NMR和19F-NMR)确证。初步考察了上述单体对丙烯酸酯类紫外光固化涂料的改性作用,结果表明,提高含氟组分比例对固化膜的初始水接触角影响较小,但经过加热后处理可显著增强固化膜的疏水性。由此推断,热处理能有效促进含氟侧基向表面迁移,且含氟侧链越长,这种向空气界面富集的倾向尤为明显。当含氟组分占涂料配方的4%～6%(质量分数,下同)时,固化膜的最大水接触角可达到120°。     

功能性含氟高分子材料

全氟代聚合物的表面具有光滑,不粘着性、憎水憎油性等含氟聚合物的固有特性,这是其他聚合物所没有的。随着科学技术的发展,对材料的要求也越来越高,功能性含氟高分子材料(以下简称氟聚合物)的应用也逐渐得到了重视。     

含氟丙烯酸酯核壳乳液的合成与性能

采用三阶段种子半连续乳液聚合,制得了以BA(丙烯酸丁酯)-MMA(甲基丙烯酸甲酯)共聚物为核,BA-MMA-TFEA(甲基丙烯酸三氟乙酯)共聚物为壳的核壳型含氟丙烯酸酯乳液.对乳液聚合过程中单体转化率的变化,特别是乳胶粒子的增长及分布的演变进行了测试和分析,证实了乳胶粒子核壳结构的形成.乳液聚合物膜的性能测试结果表明,与相同含氟单体用量的常规孔液相比,含氟聚合物富集于壳层的核壳形态有利于含氟结构单元在聚合物膜表面的分布,使用少量的含氟单体即可显著降低聚合物膜的表面能,提高其耐水性.     

具有“伞形”结构的短氟碳链含氟丙烯酸酯聚合物的制备及拒水性能

以乙烯基三氯硅烷为原料,合成了具有"伞形"结构的乙烯基三(全氟己基乙氧基)硅烷(VTHFS),将此单体与其他丙烯酸酯单体共聚,制备了一种具有"伞形"结构的短氟碳链含氟丙烯酸酯聚合物,考察了含氟单体用量对含氟丙烯酸酯聚合物接触角的影响;系统探究了"伞形"结构对聚合物材料表面接触角、吸水率、氟含量等的影响。结果表明,与线型短氟碳链含氟丙烯酸酯聚合物相比,"伞形"结构的含氟丙烯酸酯聚合物的表面接触角有明显提高,在氟含量均为60%条件下,接触角从98.2°提高到了104.4°;X射线光电子能谱测试表明其表面的含氟量亦从18.4%增加到了23.5%;"伞形"结构的含氟丙烯酸酯聚合物的吸水率也较线型聚合物有所降低。     

具有自分层效应的环保型含氟环氧自分层涂层的制备与性能

采用具有优异拒水拒油表面性能的环保型“伞形”结构短氟碳链含氟聚合物与在极性基材上附着力强的环氧树脂共混,通过自分层技术,获得能一次涂装成型的梯度含氟涂层。采用接触角测试、X射线光电子能谱和能谱详细研究了自分层形成的梯度结构及分层机理;考察了溶剂选择、基材、树脂配比、分层时间和固化温度等因素对涂膜分层和涂膜性能的影响。研究表明,当静置分层时间为3h,固化温度为80℃,基材为极性基材(马口铁和玻璃板)时,该环保型自分层涂层既具有含氟聚合物的优良表面性能,又兼具环氧树脂的优异附着力。此方法为涂层材料既保持强附着力又实现表面优异的拒水拒油功能,提供了一条新的思路和途径。     

热致性液晶聚合物的种类对环氧树脂共混物的结构和性能的影响

通过静态力学、动态力学实验方法,研究了热致性液晶聚合物(LCP)的种类对环氧树脂共混物在不同温度下的拉伸强度和应力-应变曲线的影响,通过TEM观察了共混物的相形态结构。结果表明,反应型液晶聚合物(LCPU)比其它种类的液晶聚合物对环氧树脂的改性效果更好;在不同温度下,其拉伸强度和应力~应变行为均比其它材料优越;固化物的动态力学结果表明,反应型的液晶聚合物键入了固化网络,出现新的松弛。TEM结果表明,反应型的液晶聚合物在基体材料中形成大小在纳米数量级的液晶聚集微区,没有反应基团的液晶聚合物PHBHT在10%的加入量下,与环氧的共混物结构也有液晶聚集微区产生,但是聚集区大小在微米量级。     

板料弯曲回弹影响因素的有限元模拟研究

通过静态力学、动态力学实验方法,研究了热致性液晶聚合物(LCP)的种类对环氧树脂共混物在不同温度下的拉伸强度和应力-应变曲线的影响,通过TEM观察了共混物的相形态结构.结果表明,反应型液晶聚合物(LCPU)比其它种类的液晶聚合物对环氧树脂的改性效果更好;在不同温度下,其拉伸强度和应力～应变行为均比其它材料优越;固化物的动态力学结果表明:反应型的液晶聚合物键入了固化网络,出现新的松弛,TEM结果表明,反应型的液晶聚合物在基体材料中形成大小在nm数量级的液晶聚集微区,没有反应基团的液晶聚合物PHBHT在10%的加入量下,与环氧的共混物结构也有液晶聚集微区产生,但是聚集区大小在微米量级.     

聚丙烯酸酯材料改性技术概况

聚丙烯酸酯是一类由丙烯酸酯或甲基丙烯酸酯为主要原料合成的高分子聚合物,它具有良好的力学性能、耐候性能和耐酸碱性能,其制备工艺简单,成本低廉,被广泛用作皮革涂饰、建筑涂料和木材的成膜材料.但由于纯聚丙烯酸酯的抗菌性能、力学性能和热稳定性能较差,限制了其应用范围,因此,可通过化学改性和结构设计改善其性能.利用环氧树脂改性丙烯酸酯得到的环氧丙烯酸酯兼具两者的优点,拥有良好的耐候性和热稳定性.目前环氧树脂改性丙烯酸酯主要有三种方法:物理共混法、酯化改性法、接枝共聚法.聚氨酯一般由异氰酸酯和含活泼氢的化合物聚合而成,可分为聚酯型聚氨酯和聚醚型聚氨酯.聚氨酯丙烯酸酯复合乳液固化涂膜具有优异的耐高温性能和机械加工性能,已被广泛应用于油墨、涂料、胶粘剂等领域.聚氨酯改性的方法有:物理共混法、复合共聚法、核壳共聚法、互穿聚合物网络法.氟聚合物材料具有很多优异的性能,如极低的表面能、优异的稳定性.将含氟基团引入丙烯酸酯乳液中,在固化成膜过程中,含氟基团会向膜表面富集,保护其内部结构,从而获得了性能优异的丙烯酸酯树脂.有机硅是一类无机有机高分子,可以用来连接无机物与有机物.有机硅改性丙烯酸酯的主要方法有:缩聚法、自由基聚合法、硅氢加成法、互穿网络法等.纳米材料的发展也对聚丙烯酸酯的改性起到了积极的作用,纳米材料改性聚丙烯酸酯既可以弥补乳液本身的不足,也具有纳米粒子的优良特性,目前常用的纳米粒子主要有ZnO、Fe3 O4、Al2 O3、TiO2等.本文介绍了采用环氧树脂、聚氨酯、有机氟、有机硅和纳米粒子对聚丙烯酸酯进行改性的研究进展,综述了近年来这些改性物质的结构特点、改性方法、改性性能等方面的研究成果,并对其发展方向进行了分析和展望.     

氟化丙烯酸酯聚合物的制备及表面性能的研究进展

总结了近十年来通过在聚合物链中引入含氟基团，得到氟化丙烯酸酯聚合物的研制及表面性能的研究进展。     

Frictional properties of an immobilized fluorinated polymer nanosheet

The frictional properties of an immobilized fluorinated polymer nanosheet were investigated to develop an ultrathin solid lubrication film with an excellent wear-resistant. N-(1H,1H-Pentadecafluorooctylmethacrylamide) copolymers containing carboxyl group as a reactive moiety form a stable monolayer on the water surface and a highly ordered reactive fluorinated polymer nanosheet can be fabricated by the Langmuir-Blodgett technique. The reactive fluorinated polymer nanosheet was immobilized onto solid substrates through chemical binding with an aminosilane coupling agent, and the film showed smooth surface even after the reaction. The immobilized fluorinated polymer nanosheet had a low friction coefficient and strong wear-resistant.     

Structural, mechanical, and tribological properties of fluorinated mesoporous silica films: Effect of functional moiety and surfactant template concentrations

Thin organo-functional coatings are inherently weak and can be easily damaged and their functional properties degraded by wear. Encapsulating organo-functional moieties into surfactant-templated ceramic coatings has the possibility of extending the functional lifetime of such materials. This study examines the effects of functional silane and surfactant template concentrations on the structural, mechanical, and tribological properties of hydrophobic silica films. Fluorinated silica films were synthesized via sol-gel co-condensation of tetraethoxysilane and a perfluoropolyether silane, templated with PEO₁₀₆PPO₇₀PEO₁₀₆ surfactant (Pluronic F127), and coated on glass substrates. The results show that the increasing concentrations of fluorinated silane and surfactant template generally improve hydrophobicity of films worn by abrasion. However, surfactant templating creates void spaces which are detrimental to the mechanical properties of the material, as was determined by nitrogen adsorption porosimetry and nanoindentation. Tribological results from atomic force microscopy suggest that the low-friction surface generated by encapsulation of fluorosilane moieties grafted to internal surfaces mitigates to some extent the detrimental effect of film porosity on hardness and wear resistance.     

Komplexe zur Herstellung niederenergetischer Oberflächen

Low Surface Energie from Waterborne Nano‐Dispersions of Polymer Complexes Waterborne nano‐dispersions with a supra‐molecular ordering were prepared by using a commercially available polyelectrolyte and a fluorinated surfactant. From this complex, thin coatings on chemically very different surfaces can be prepared at room temperature without using organic solvents. The resulting coatings are smooth, optically invisible and have low surface energies. Critical surface tensions according to Zisman [16] were determined to be in the range from 5.7 to 13.1 mN/m and dispersive surface energies according to the Girifalco‐Good‐Fowkes‐Young equation [17, 18] are in the range from 10.2 to 10.7 mN/m. The low surface energies observed for fluorinated polyelectrolyte surfactant complexes as well as their liquid crystalline‐like structures are caused by the strong segregation tendency of fluorinated and ionic moieties [27].     

侧基含氟聚合物结构与表面性质研究进展

综述了含氟聚合物的侧基结构、侧基有序性及对表面性质的影响,并对实现侧基含氟聚合物表面性质优化、环境稳定性进行了展望。     

Photo-induced liquid crystal alignment of poly(vinyl cinnamate) and fluorinated polyimide blends

Liquid crystal(LC) alignment properties were mainly affected by surface properties of alignment layers. In our previous work, we prepared poly(vinyl cinnamate) (PVCi) and polyimide blend alignment layer for thermally stable LC alignment. In this work, we utilized fluorinated polyimide for blend alignment layers in order to modify surface properties of alignment layers. For this purpose, polyimides containing fluorine unit were synthesized and used for the blend alignment layers. Fluorine containing diamine, 4,4′-bis[2-(4-aminophenyl)hexafluoropropyl]-diphenyl ether(BDAF), is used for the polyimide synthesis. We prepared the fluorinated polyimide and PVCi blend alignment layers and investigated the effect of fluorine on the LC alignment properties and pretilt angle of LC.     

Surface Electrical Properties of Fluorinated Epoxy Resin and Influence of Ambient Humidity

As-prepared epoxy resin samples were surface fluorinated using a F₂/N₂ mixture. The fluorination resulted in a remarkable increase in surface conductivity of the epoxy sample by over three orders of magnitude. Corona charges deposited on the fluorinated surface could not be stored even at room temperature. Obvious dependence of surface conductivity and steady state surface current on ambient humidity was found for the fluorinated sample. ATR-IR analysis and SEM imaging of surface and cross-section demonstrated substantial changes in surface layer chemical composition and morphology due to the fluorination, which are responsible for the changes in surface electrical properties.     

共聚物链结构对共聚型含氟聚酰亚胺薄膜性能的影响

以4,4'-二氨基-2,2'-双三氟甲基联苯(TFMB)、4,4'-(六氟异丙烯)二酞酸酐(6FDA)和3,3',4,4'-联苯四甲酸二酐(BPDA)为反应单体,改变非含氟BPDA单体在二酐中的配比和加料方式制备出一系列共聚型含氟聚酰亚胺(PI)薄膜并表征和分析其性能,研究了共聚物链结构对其性能的影响。结果表明,BPDA单体的加料方式及其在二酐单体中的比例均影响薄膜的性能。共聚型含氟PI薄膜在室温下均溶于非质子极性溶剂,且在可见光范围内有较高的透光率。随着非含氟二酐单体BPDA含量的提高薄膜的光学性能略有降低而其热性能和力学拉伸性能提高。非含氟二酐单体占二酐单体的比例为68.97%的共聚型PI薄膜,在500 nm处的透过率达到96.01%;非含氟二酐单体占二酐单体比例为35.71%的共聚型PI薄膜失重10%的热分解温度为595.23℃,拉伸强度为100.98 MPa。同时,BPDA加料方式的改变对共聚型PI薄膜的光学性能、热学性能和力学拉伸性能均有不同程度的影响。     

Direct fluorination of Twaron fiber and the mechanical, thermal and crystallization behaviour of short Twaron fiber reinforced polypropylene composites

An experimental study of the incorporation of non-fluorinated and fluorinated Twaron fibers in polypropylene (PP) is presented. Surface modifications were made to Twaron fiber by direct fluorination technique using elemental fluorine in order to improve the interfacial adhesion between the fiber and matrix. Composites of PP/Twaron fiber (both Fluorinated and non-fluorinated) with 0.6%, 1.25%, 5% and 10% of Twaron fibers (w/w) were prepared by a solution method. Mechanical behaviour was estimated by the measurement of the tensile strength. The mechanical properties of PP improve significantly with the incorporation of Twaron fibers and fluorinated fiber composites show superior mechanical properties compared to the non-fluorinated system. The morphology was determined by scanning electron microscopy (SEM), showing good dispersion of the fibers. The thermal and crystallization behaviour of PP/Twaron fiber composites were studied by thermogravimetry (TG) and differential scanning calorimetry (DSC). The effect of fiber content and fiber surface treatments on the thermal properties was evaluated. DSC analysis exhibited an increase in the crystallization temperature and crystallinity, melting temperature upon the addition of fluorinated fibers to the PP matrix. This is attributed to the nucleating effects of the fiber surfaces. Also the thermal stability (from TG) and surface energy (determined from contact angle measurement) increased for fluorinated fiber composites. Surface modification of Twaron fibers leads to improved adhesion with the PP matrix and hence an improvement in properties of the Twaron fiber-PP composites.     

含氟聚氨酯的合成及其应用研究进展

含氟聚氨酯综合了聚氨酯和含氟聚合物的优点,如具有极好的耐紫外线和核辐射性、柔韧性,优良耐磨性,低表面能和高耐候性等.因此,对含氟聚氨酯的研究成为近年来的研究热点.本文综述了含氟聚氨酯的合成、性能及应用研究发展状况,并对今后的研究发展进行了展望.