High-temperature catalysts with a synergetic effect of Pd and manganese oxides

A synergetic effect in the catalytic activity has been found after palladium introduction in Mn–Al–O systems. The magnitude of the synergetic effect depends on the types of the oxidic manganese species: oxide Mn₃O₄, spinel (Mn, Mg)[Mn, Al]₂O₄ or hexaaluminate (Mn, Mg)LaAl₁₁O₁₉. The synergetic effect of Pd and manganese-containing compounds is observed only if palladium is introduced to the low-temperature precursor of the manganese alumina spinel or manganese hexaaluminate. The synergetic effect is not observed when high-temperature samples with formed spinel or hexaaluminate phases are modified with Pd.     

Structure development and properties of high-speed melt spun poly(butylene terephthalate)/poly(butylene adipate-co-terephthalate) bicomponent fibers

Ultra-high-speed bicomponent spinning of poly(butylene terephthalate) (PBT) as sheath and biodegradable poly(butylene adipate-co-terephthalate) (PBAT) as core was accomplished with the take-up velocity up to 10 km/min. The structure development of the individual component and the properties of PBT/PBAT fibers were investigated through the measurements on differential scanning calorimetry, wide-angle X-ray diffraction, birefringence and tensile test. Due to the mutual interaction between two polymer-melts along the spinline, the processability of both components in PBT/PBAT bicomponent spinning was improved compared with those of corresponding single component spinnings. Furthermore, in PBT/PBAT fibers, the structure development of PBT component was found to be greatly enhanced, which led to the improvement in its thermal and mechanical properties; whereas the structure development of PBAT component was significantly suppressed, in which nearly non-oriented structure was observed in both crystalline and amorphous phases.     

可生物降解纤维——聚乳酸(PLA)纤维——第Ⅱ报.性能特征及其应用前景

介绍了生物可降解纤维——聚乳酸纤维的性能特征及其在混纺、非织造布、服装、装饰、医疗等领域的应用前景。     

Development and Characterization of the Injection-Molded Polymer Composites Made from Bicomponent Fibers

The results of this study are related to the implementation of the concept of self-reinforced composites. The input materials in preparation process were the bicomponent fibers. The studies were carried out on three types of fibers, HDPE/PP, cPP/PP, LPET/PET. In each case, the matrix material was a low melting polymer, and the core was made of a higher melting point polymer. The research was conducted for the materials shaped by an injection-molding technique. The analyses confirmed the two-component structure. Properties of the resulting composites confirmed the applicability of bicomponent fibers in the preparation of self-reinforced composites.     

双组分纺粘法非织造布介绍

介绍了新型双组分纺粘法非织造布的生产技术,说明了双组分纺粘法非织造布具有良好的性能,应用领域广泛,是具有发展前途的产品.     

桔瓣型双组分纺黏水刺超纤技术及其应用

探讨桔瓣型双组分纺黏水刺超纤技术及其应用前景.介绍了桔辩型双组分纺黏水刺超纤技术的工艺原理及采用这种工艺生产超细纤维非织造布的优势,并阐述其产品的特点、应用领域及当前发展状况.指出:我国非织造技术与发达国家仍存在着较大差距,桔瓣型双组分纺黏水刺技术作为一种先进的非织造加工工艺,代表着当今世界非织造技术发展的一个重要方向,具有良好的市场前景.     

Effects of drawing process on crimp formation-ability of side-by-side bicomponent filament yarns produced from recycled,fiber-grade and bottle-grade PET

In this study, side-by-side bicomponent filaments from recycled poly(ethylene) terephthalate (R-PET) from post-consumer bottles, fiber-grade PET (FG-PET) and bottle-grade PET (BG-PET) successfully were extruded. The bicomponent fibers in the forms of FG/R, BG/R and FG/BG were produced in a spinning machine and drawn by a thermal drawing process to improve their mechanical properties using draw ratios between ‘2.5 and 2.8’. The effects of conditions on the fiber structure, physical properties and crimp formation of resultant fibers were evaluated. The birefringence, shrinkage and mechanical properties, such as tensile strength and tensile modulus, increased and elongation at break decreased for the drawn fibers, and this was attributed to the fiber orientation. Distinct crimp formation was observed from drawn bicomponent fibers after thermal treatment. There were significant birefringence and shrinkage difference between two components in drawn bicomponent fibers caused to severe crimp formation.     

纺粘法生产新方法的发展趋势

概括的介绍了纺粘法的四种最新生产技术 ,及纺粘法生产方法的发展趋势     

Some investigations on the fiber formation by utilizing a side-by-side bicomponent electrospinning approach

Simultaneous electrospinning of two polymer solutions in a side-by-side fashion is conducted for two bicomponent polymer systems—poly (vinyl chloride)/segmented polyurethane (PVC/Estane^®) and poly(vinyl chloride)/poly(vinylidiene fluoride) (PVC/PVDF). The new experimental device is described and suitable process conditions to electrospin bicomponent fibers are described. Field emission scanning electron microscopy and energy dispersive spectroscopy were utilized to interpret the results regarding local structure and chemical composition, respectively.