Morphology and texture development of uniaxially stretched poly(ethylene naphthalene‐2,6‐dicarboxylate)

The texture development of PEN films with different semicrystalline morphologies have been studied by X‐ray diffraction. These different structures have been obtained by uniaxially stretching PEN amorphous films at 100 and 160°C (below and above T_g) at different drawing ratios. Samples have also been characterized by DSC to determine the crystallinity ratios, the crystallization, and melting temperatures. To define the orientation of crystallites in the oriented samples, pole figures have been constructed, as a function of temperature and drawing ratio (DR) in the range 1.5–4. In the range from DR = 2 to 4 the orientation is clearly uniplanar‐axial. At T_draw = 100°C the crystallinity shown by DSC analysis is higher than the sample stretched at 160°C. The orientation is also higher when samples are stretched at 100°C. The naphthalene rings mainly stay in the plane of the film with a lower fraction perpendicular to the plane of the film. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 395–401, 2007     

Fabrication of anode supported PEN for solid oxide fuel cell

ConventionalSOFCsareusuallyoperatedat 10 0 0℃ Duetoitshighoperationaltemperature ,thematerialsdemandinguponSOFCcomponentsarequitestringent Manyresearchersaregradu allyinterestedinintermediatetemperaturesolidoxidefuelcell(IT SOFC) [1-2 ] TherearetwopossibleapproachesforloweringtheoperatingtemperatureofSOFCs Thefirstistoreducethethicknessofelec trolyte ,forexampletheelectrolyteinanode supportedplanar typesinglecellisonly 2 0 μm Thesecondistodevelophigherconducti vityelectrolyte .Inth…     

固体氧化物燃料电池关键材料的开发

在对固体氧化物燃料电池特点进行简述的基础上,重点就我所固体氧化物燃料电池研究与开发所取得的进展及所遇到的问题进行了讨论.在总结所取得科研成果的基础上,对我国固体氧化物燃料电池的研究与开发前景作了展望.     

PET/PEN瓶坯成型工艺分析与注射模设计

使用Moldflow软件分析了一模两腔PET/PEN瓶坯热流道注射模注射成型过程,直观地模拟出塑料成型的充填、流动及冷却过程。预测PET/PEN瓶坯成型过程中可能出现的缺陷,优化冷却水道直径、布局和浇注系统尺寸,提出优化注射方案,对优化后方案进行可行性模拟,预测和解决PET/PEN瓶坯设计、模具设计及成型过程中存在的缺陷,具有快速、准确、方便、高效等优势,可以缩短模具制造周期,降低成本,提高生产效率。     

新型聚酯PEN的开发概况及发展前景

简述了聚萘二甲酸乙二醇酯(PEN)的性能及其工艺原理,综述了国内外有关新型聚酯材料PEN的研究概况和开发现状,并指出其应用领域及其发展前景。     

2,6-二烷基萘的应用及开发

芳香族高聚物的发展,已引起了人们越来越多的重视。本文对合成新型高聚物的重要原料2,6-二烷基萘进行了介绍,并对其主要的用途,特别是其高聚物PEN的各种应用进行了详细介绍,最后介绍了其在各个领域的开发。     

Phase separation,physical properties and melt rheology of a range of variously transesterified amorphous poly(ethylene terephthalate)–poly(ethylene naphthalate) blends

Amorphous, partially transesterified poly(ethylene terephthalate)/poly(ethylene naphthalate) (PET/PEN) blends of different levels of transesterification and blend composition were investigated in terms of resultant phase behavior, thermal transitions, and melt rheological properties. Intrinsic viscosities of the lowest transesterified material were found to be significantly below those of a physical blend of an identical composition, but at higher levels of transesterification, there was little difference. This was similarly found in melt rheometry measurements, where the zero‐shear rate viscosity of the low and highly transesterified mixtures were similar. Both solution and melt rheometry indicated that the molecular weight decreased by thermal degradation from processing. This is believed to play an important role in determining the final molecular architecture and properties. For similar levels of ester interchange, there was a minimum observed in zero shear melt viscosity at around 40 wt % PEN. This is likely due to competition between the slightly transesterified copolymer chains having poorer packing in the melt and reduced entanglement. Differential scanning calorimetry and dynamic mechanical thermal analysis were used to investigate the phase behavior of partially and fully transesterified blends. Results for the glass transition of the highly transesterified blends were compared with the theoretical values calculated from the Fox equation and were found to be close, although slightly lower. A correlation between the melting temperature of the blend and the degree of transesterification was shown to exist. This correlation can be used to estimate the degree of ester exchange reaction from these melting transitions. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1556–1567, 2002     

耐热瓶级PEN／PET合金材料研制和开发应用

针对PEN与PET的合金化及PEN／PET于耐热中空包装容器上的应用进行探索研究。研究表明：PEN与PET的酯交换反应主要由反应时间和温度决定。研究确定了适合应用要求的相容程度（即酯交换率）。本文通过控制螺杆挤出工艺条件,使PEN、PET成为适度相容的耐热瓶级PEN／PET合金材料,该材料在PET基础上,提高了阻气性和耐热性,同时具有与现行注吹设备的设备兼容性、工艺可行性和易为市场接受的经济性。本研究采用国产二步法机器和通用聚酯瓶的成型工艺加工成型耐85℃以上湿度的果汁、茶饮料等热封装瓶,填补了耐热瓶塑料材料和耐热瓶制品的国内空白。     

A review on the mechanical and electrical properties of graphite and modified graphite reinforced polymer composites

Carbon materials particularly in the form of sparkling diamonds have held mankind spellbound for centuries, and in its other forms, like coal and coke continue to serve mankind as a fuel material, like carbon black, carbon fibers, carbon nanofibers and carbon nanotubes meet requirements of reinforcing filler in several applications. All these various forms of carbon are possible because of the element's unique hybridization ability. Graphene (a single two-dimensional layer of carbon atoms bonded together in the hexagonal graphite lattice), the basic building block of graphite, is at the epicenter of present-day materials research because of its high values of Young's modulus, fracture strength, thermal conductivity, specific surface area and fascinating transport phenomena leading to its use in multifarious applications like energy storage materials, liquid crystal devices, mechanical resonators and polymer composites. In this review, we focus on graphite and describe its various modifications for use as modified fillers in polymer matrices for creating polymer-carbon nanocomposites.