燃料电池复合石墨双极板基材的研究进展：材料、结构与性能

双极板是燃料电池的重要组成部件,需要满足导电、抗弯强度、耐腐蚀等方面性能的要求。复合石墨双极板具有成本低、耐腐蚀性好、易成型等优势,是双极板的一个重要研究方向。复合石墨双极板的导电功能是由以石墨为代表的导电填料相互连接形成传导网络实现的,抗弯强度及气密等性能则主要依靠树脂固化形成的基体。因此,复合石墨双极板性能不仅受到导电填料以及树脂性能的影响,同时导电填料、树脂固化形成的结构对于极板性能也有着不可忽视的影响。本文总结了导电填料及树脂的性质、改性方法等对于复合石墨极板性能的影响,并分析了分子结构以及制备工艺对于极板结构以及实用性能的影响规律。导电填料与树脂的相容性受到原料表面官能团的影响,并直接影响了导电填料的离散均匀度以及导电填料/树脂的界面性能。通过填料诱导工艺优化导电网络,能够有效提升极板的导电性能。基于对研究现状的总结,本文对复合石墨极板开发的未来发展方向进行了展望。     

人造岩石固wx 包容锕系核素废物

研究了富钙钛锆石型和富烧绿石型两种人造岩石固化体包容锕系核素的配方设计和固化产品的鉴定评价,包括物理性能、抗浸出性能和耐辐照性能。采用了X射线衍射(XRD)、扫描电镜/能谱分析(SEM/EDS)和透射电镜/能谱分析(TEM/EDS)研究了矿相组合、元素分布和矿相化学组成等。研究表明,富钙钛锆石和富烧绿石型人造岩石都能很好地固化包容锕系核素废物。     

人造岩石固wx 包容锕系核素废物

研究了富钙钛锆石型和富烧绿石型两种人造岩石固化体包容锕系核素的配方设计和固化产品的鉴定评价,包括物理性能、抗浸出性能和耐辐照性能。采用了X射线衍射(XRD)、扫描电镜/能谱分析(SEM/EDS)和透射电镜/能谱分析(TEM/EDS)研究了矿相组合、元素分布和矿相化学组成等。研究表明,富钙钛锆石和富烧绿石型人造岩石都能很好地固化包容锕系核素废物。     

有机光导器件用聚酯成膜剂的合成及表征

以对苯二甲酸、间苯二甲酸、新戊二醇及1，6-己二醇为原料进行四元共缩聚反应，得到聚酯型树脂。利用^1H核磁共振谱测定聚酯中各组分含量，测试了聚酯的耐磨性，并用合成的聚酯与聚碳酸酯共混制备光导器件，利用SP-428型静电纸分析仪测试光导器件的光电性能。实验结果表明由聚酯和聚碳酸酯共混物制备的有机光导器件能有效地防止光疲劳现象。     

不饱和聚酯树脂的减收缩研究(Ⅱ)——几种饱和聚酯的减收缩作用

饱和聚酯作为减缩剂的优点是制品表面光洁,所得低收缩UP-树脂透明度较好,往往为半透明,使制品外观与原UP-树脂差不多,从而扩大了制品的用途。我们在酸和醇的种类及比例上进行了探索,合成了7种低分子量饱和聚酯并测试了它们的减收缩效果。发现芳香族聚酯具有更好的减收缩性能,其中具有封端结构的效果更佳。此外,制备了几种无填料浇     

聚酯的生物改性

从四个方面综述了近年来聚对苯二甲酸乙二酯(PET)和聚对苯二甲酸丁二酯(PBT)生物改性的研究进展:(1)在聚酯合成中采用生物原料;(2)采用共聚技术制备可生物降解性共聚酯;(3)生物活性物质在聚酯中的引入改性,可提高其生物相容性和抗菌能力,在聚酯用于人造器官时,可使血管纤维原细胞的细胞增殖;(4)生物酶对聚酯进行水解改性,可减轻重量,并改善吸湿性、染色性等性能。     

层状前体镁铁水滑石及磁性材料的制备及表征

本文提出了利用镁铁水滑石作为磁性材料前体再经高温焙烧制备尖晶石型铁氧体的思路,深入研究了水滑石的制备工艺及结构性能并初步探讨了其焙烧后的磁学性能。由共沉淀法合成了Mg/Fe摩尔比为2,3,4,6的镁铁水滑石,XRD结果表明随镁铁比增大、晶化温度的升高及晶化时间的延长,水滑石的晶体结构规整性增强;热重-差热结果显示镁铁水滑石的分解有两个过程,随着镁铁比增大,水滑石的热稳定性提高。高温焙烧后的镁铁水滑石具有较好的磁学性能。     

可降解聚氨酯骨胶黏剂的研究

以ε-己内酯、乙交酯和D,L-丙交酯为单体,丙三醇为起始剂,辛酸亚锡为催化剂,合成了不同分子量的聚酯三元醇。随后将合成的聚酯三元醇引入到聚氨酯(PU)体系中,得到聚氨酯骨胶黏剂。利用核磁共振氢谱和红外光谱表征了聚酯三元醇和聚氨酯胶黏剂的结构。用扫描电子显微镜、万能拉力试验机、差示扫描量热分析仪及恒温震荡箱等研究了不同分子量聚酯三元醇及填料的加入对胶黏剂表面形貌、压缩性能、玻璃化转变温度(T_g)、黏接强度及降解性能的影响。结果表明:含有理论数均分子量为400的聚酯三元醇并添加填料的聚氨酯胶黏剂(PU-6C400-F)显示出较好的综合性能,黏接强度为0.93 MPa,压缩强度与模量分别为12.5 MPa与128.0 MPa,该体系有望取代聚甲基丙烯酸甲酯(PMMA)作为骨胶黏剂使用。     

高效制备液相色谱柱技术的研究进展

本文概述了高效制备液相色谱柱的柱型结构、填料以及柱填充方法等研究的最新进展,讨论了制备柱与分析柱的不同特征,对目前普遍使用的压缩型制备柱的类型、结构及填充方法作了较为全面的评述,总结比较了工业化制备色谱填料不同于分析色谱填料的特点,探讨了高效制备液相色谱柱技术的应用和发展前景.     

同时添加碳纳米管及石墨烯对热致液晶聚酯形状记忆行为及拉伸性能的影响

利用溶液共混的方法将碳纳米管(CNT)及石墨烯(G)同时加入到热致液晶聚酯中制备纳米复合材料.通过透射电镜(TEM)研究纳米粒子的分散及形貌.采用荧光光谱及拉曼光谱研究碳纳米填料与热致液晶聚酯基体之间存在π-π相互作用.利用电子万能试验机(EUTM)研究了材料的拉伸性能,由于CNT与G与基材之间作用力强,且CNT与G间的协效作用能有效地实现应力转移,同时加入CNT及G有助于提升复合材料的拉伸强度.动态热机械分析(DMA)数据表明,同时添加CNT与G对于复合材料的固定率影响不大,但会降低回复率;同时复合材料的回复应力也得到显著的提升.     

Colloidal systems containing free radical‐forming particles and composites on their basis

Controlled surface activity and reactivity of new carbon‐chain functional surface‐active oligoperoxides (FSAP) and derived metal complexes (OMC) with side and end di‐tertiary and tert‐alkyl (aryl) peroxidic, respectively, and other active functional groups cause the possibility of their tailored utilization as emulsifiers, surface‐active initiators and modifiers of the phase boundaries of liquid, solid and mixed phases in different colloidal systems in a wide temperature range. New materials can be developed such as water and hydrocarbon polymer dispersions, artificial water dispersions of unsaturated polyesters and alkyd resins, polymer/polymeric blends, active glass and carbon fibers, dispersed fillers, reinfourced and filled polymer composites with the definite special properties. Methods for the obtaining and the application of these materials are described.     

Polymerization of Vinyl Monomers on Mineral Surfaces; A Novel Method of Preparing Reinforcing Fillers

A novel method for producing modified mineral fillers is reported: The mineral surface is first made “acidic” and this acidic surface is used to initiate the cationic polymerization of vinyl or preferably divinyl monomers, the residual acidic sites being subsequently neutralized with ammonia or an organic base. During compounding, grafting occurs between the encapsulating polymer layer and the matrix polymer via previously formed peroxidic groups in this layer or via radical attachment at unsaturated centers in the polymer coating. The incorporation of these modified fillers in various grades of polyethylene results in significant improvements in processability and in tensile and impact strength relative to the properties of equivalent composites using untreated or merely hydrophobic fillers.     

氨氮与磷在三种人工湿地填料上的吸附动力学

利用吸附动力学实验研究了浮石、陶结和陶粒对氨氮和磷的吸附动力学特征.结果表明:浮石对氨氮与磷的吸附容量明显比陶结和陶粒的大.人工湿地填料浮石和陶粒对氨氮与磷,以及陶结对氨氮的等温吸附动力学特征均可以用准一级、准二级和Bangham模型加以描述.其中浮石对氨氮和磷以及陶结对氨氮的吸附以化学吸附反应控制为主,而陶粒对磷的吸附过程则以扩散反应控制为主.三种填料对氨氮和磷的吸附均以表面吸附为主.     

Nanocomposite membranes for organic solvent nanofiltration

Organic solvent nanofiltration (OSN) is a molecular separation method which offers a sustainable and reliable solution compared to the conventional energy-intensive separation processes. OSN can be successfully applied to several applications, such as food, pharmaceutical, petrochemical and fine-chemical industries. Current research on OSN membranes mainly focuses on polymeric materials due to the ease of processing, controlled formation of pores, lower fabrication costs and higher flexibility as compared with inorganic materials. However, there are some limitations for the polymeric membranes which can be partially surmounted by adding nanoscale fillers into the polymeric matrix to make nanocomposite membranes. This review aims to comprehensively evaluate and report the advances in nanocomposite membranes prepared by using either different nanoscale fillers or various fabrication methods for OSN applications. Nanoparticles that will be discussed include metal-organic framework, graphene oxide, carbon nanotubes, silica, titanium, gold, zeolite and other fillers. The incorporation of these nanoscale fillers into the polymeric membranes can positively influence the mechanical strength, chemical and thermal stability, hydrophilicity, solute selectivity and solvent permeance. This study may provide helpful insights to develop next-generation of OSN membranes for years to come.     

Microfillers – Advantageous Potential for White Goods Industry

Market advantage of contemporary appliance product development heavily depends on the polymer materials and related fillers – e.g. micro-fillers. Presented and analyzed is washing machine, its vital product component - plastic tub. Namely, during the product life cycle it is exposed to the simultaneous and severe dynamic thermo-mechanical loads. Material selection for suitable polymer composite is conducted predominantly with time-dependency criteria – creep property at various thermo-mechanical conditions. Experimental validation and polymer material benchmarking is implemented on already regular polymer composites with mineral fillers from 4 different appliance producers (PP + 40 × CaCO₃) on one side with the regular, on market accessible microfiller on other side. The overall study contain comparison of regular PP as basic, reference property in comparison with regular mineral fillers with/without technology processing and microfillers. All these data provide necessary and proper procedure path for the polymer product designer to conduct rational and reliable polymer material selection during polymer product development.     

Composites of Wood and Biodegradable Thermoplastics: A Review

This paper is an overview of current understanding in the areas of composites made from biodegradable thermoplastics and wood fillers. The review finds that the composite properties depend on the type of wood filler, the choice of polymer matrix, the wood filler content, the compatibilization technique used and the processing parameters. The extent of interfacial adhesion and the filler morphology are identified as the underlying factors that control the composite properties. Future research needs are identified, including establishment of fundamental relationships between quantified interfacial adhesion and end-use properties and advanced modelling of biodegradation processes.     

Synthesis and characterization of bismaleimide–polyurethane crosslinked copolymers

A series of novel crosslinked copolymers of bismaleimide (BMI) and polyurethanes (PU) were prepared by direct copolymerization of BMI monomer and urethane-modified bismaleimide (UBMI). The copolymers were characterized by FT-IR and solid state ¹³C-NMR. The reaction rate of the BMI monomer can be significantly increased by copolymerization with UBMI. The crosslinked copolymers show good mechanical properties and high thermal stability. Studies on glass transition temperatures and dynamic mechanical properties indicate that the copolymer is a homogeneous system as the polyester-type PU employed. The transmission electron microscopy (TEM) of the copolymer illustrated a one-phase structure of the cured resins when the polyester-type PU was incorporated. © 1995 John Wiley & Sons, Inc.     

Mechanical and thermal investigation of thermoplastic nanocomposite films fabricated using micro- and nano-sized fillers from recycled cotton T-shirts

The thermal and mechanical performance of composites with nano-sized cotton fillers embedded in low-density polyethylene (LDPE) is investigated. Microfibrillated cotton was prepared by microgrinding mechanical treatment of pulverized cotton (pCot) derived from waste T-shirts, resulting in nano-sized fibrils of the cellulose that retain high crystallinity. Film composites of LDPE with pCot before and after microgrinding were fabricated through melt extrusion and the effect of filler size on mechanical, thermal and morphological properties of the composite was investigated. Compounding microfibrillated cotton with LDPE resulted in well-dispersed nanocomposites with no discoloration after 10 min of melt extrusion at 170 °C. At concentrations up to 10 % by weight, the composites showed increased modulus, increased tensile strength and a slight decrease in elongation to break. Further improvement in the dispersion and mechanical properties of the cotton-based fillers was realized by the use of LDPE powder instead of polymer pellets fed to the extruder. This research demonstrates the processing and applicability of the use of recycled cotton-based nano-sized fillers in melt-processing.     

Structure–property relationship of octa‐substituted POSS in thermal and mechanical reinforcements of conventional polymers

In this article, we describe the structure–property relationships between the polyoctahedral oligomeric silsesquioxane (POSS) fillers and the thermomechanical properties of the polymer composites using polystyrene, poly(methyl methacrylate), and ethylene‐(vinyl acetate) copolymer. We used eight kinds of octa‐substituted aliphatic and aromatic POSS as a filler, and homogeneous polymer composites were prepared with various concentrations of these POSS fillers. From a series of measurements of thermal and mechanical properties of the polymer composites, it was summarized that the longer alkyl chains and unsaturated bonds at the side chains in POSS are favorable to improve the thermal stability and the elasticity of polymer matrices. It was found that phenyl‐POSS can show superior ability to improve the thermomechanical properties of conventional polymers used in this study. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5690–5697, 2009     

Chemical and spectroscopic investigation on the plaster of a Byzantine church

The discovery of a Byzantine church under the floor of one of the oldest churches of Salerno (Italy) has given us the opportunity to investigate the fine composition of the plaster through chemical and spectroscopic methods. In particular, considering that plasters are generally formed by a carbonate phase (carbonates) and an inert phase (silicates), the characterization, performed on the carbonate phase by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA), has revealed the presence of dolomite minerals. This information indicates that, during the building process, some accessory minerals of marble were added in the mortar to be used like fillers. The carbonate phase makes too difficult the spectroscopic characterization of the inert phase. Only by acid attack of the plaster the inert phase has been isolated and its characterization, by XRD and optical microscopy, has indicated the presence of olivine minerals and other typical silicates of river sands.