Preparation and electrochemical characterization of Ti-based amorphous metallic glass with high strength

Ti-based amorphous metallic glasses have excellent mechanical, physical, and chemical properties, which is an important development direction and research hotspot of metal composite reinforcement. As a stable, simple, efficient, and large-scale preparation technology of metallic powders, the gas atomization process provides an effective way of preparing amorphous metallic glasses. In this study, the controllable fabrication of a Ti-based amorphous powder, with high efficiency, has been realized by using gas atomization. The scanning electron microscope, energy-dispersive spectrometer, and X-ray diffraction are used to analyze surface morphology, element distribution, and phase structure, respectively. A microhardness tester is used to measure the mechanical property. An electrochemical workstation is used to characterize corrosion behavior. The results show that as-prepared microparticles are more uniform and exhibit good amorphous characteristics. The mechanical test shows that the hardness of amorphous powder is significantly increased as compared with that before preparation, which has the prospect of being an important part of engineering reinforced materials. Further electrochemical measurement shows that the corrosion resistance of the as-prepared sample is also significantly improved. This study has laid a solid foundation for expanding applications of Ti-based metallic glasses, especially in heavy-duty and corrosive domains.     

PET熔体长距离输送影响因素探讨

介绍了PET熔体长距离输送工艺流程,重点分析易对PET熔体输送带来不利影响的因素,如熔体压力降、停留时间、管道粗糙度、焊缝品质等,并针对熔体输送的不利因素,提出了相应的解决方案,对熔体直纺设计、实践提供必要的参考。     

Random poly(ε‐caprolactone‐L‐alanine) by direct melt copolymerization

A series of random polyesteramides (PEAs) with a range of molar composition from 90/10 to 50/50 were synthesized by direct melt polycondensation of ε‐caprolactone and l ‐alanine. Their structure was fully characterized by Fourier transform IR and NMR spectroscopy. The resulting copolymers are completely amorphous with the exception of PEA‐90/10 which possesses a semicrystalline structure. These PEAs present increasing glass transition temperatures at increasing l ‐alanine contents and exhibit fairly good thermal stability with 10% mass loss temperatures reaching 315 °C. © 2020 Society of Industrial Chemistry     

流变仪在覆铜板工序中的应用

本文简要叙述利用流变仪对覆铜箔层压板生产工序中的胶液和半固化片参数进行控制,从而更好地保证胶液和 半固化片性状的一致性,以有利于控制板材流胶和品质。     

水煤浆燃烧技术及其发展

分析了水煤浆雾化燃烧的技术状况、应用方向和存在问题，介绍了水煤浆流化—悬浮高效洁净燃烧新技术及其优点，结合实践应用情况，分析了发展水煤浆流化—悬浮燃烧技术的意义和应用前景。     

PP－g－AA的制备和表征

用熔融接枝方法制备了聚丙烯－ｇ－丙烯酸（ＰＰ－ｇ－ＡＡ）。用光电子能谱，广角Ｘ射线衍射，红外光谱和化学滴定方法对接枝物进行了定性和定量表征。讨论了单体和引发剂浓度对接枝率的影响，确定了用红外光谱法测定接枝物含量的经验公式     

固相缩聚共聚酯的熔融行为和结晶速率研究

通过固相缩聚合成了两种不同结构的高分子量共聚酯，研究了样品的熔融行为和结晶速率。研究发现，共聚酯的熔融峰随着固相聚合温度和时间的变化而与纯ＰＥＴ有明显的差别，共聚酯泊结晶速率与慢于纯ＰＥＴ的结晶速率。     

纺丝组件漏浆原因分析

通过对纺丝组件工艺对比调试,分析了纺丝组件消耗材料对纺丝组件漏浆的影响,指出了纺丝组件漏浆的主要影响因素。     

Synthesis and characterisation of copolyesters from poly(ethylene terephthalate) and poly(hexamethylene terephthalate)

Copolyesters containing poly(ethylene terephthalate) and poly(hexamethylene terephthalate) (PHT) were prepared by a melt condensation reaction. The copolymers were characterised by infrared spectroscopy and intrinsic viscosity measurements. The density of the copolyesters decreased with increasing percentage of PHT segments in the backbone. Glass transition temperatures (T_g). melting points (T_m) and crystallisation temperatures (T_c) were determined by differential scanning calorimetry. An increase in the percentage of PHT resulted in decrease in T_g, T_m and T_c. The as-prepared copolyesters were crystalline in nature and no exotherm indicative of cold crystallisation was observed. The relative thermal stability of the polymers was evaluated by dynamic thermogravimetry in a nitrogen atmosphere. An increase in percentage of PHT resulted in a decrease in initial decomposition temperature. The rate of crystallisation of the copolymers was studied by small angle light scattering. An increase in percentage of PHT resulted in an increase in the rate of crystallisation.     

熔融-固相缩聚法中固相聚合对聚乳酸合成的影响

以L 乳酸单体为原料 ,熔融 -固相缩聚法合成了聚乳酸 ,重点研究了固相聚合的工艺条件。结果表明 ,绝对压力 60Pa ,氯化亚锡为催化剂 ,分段控温 ,可使聚乳酸的粘均分子量提高到固相聚合反应前的 5 3倍。通过对固相聚合产物的结晶度和熔点的分析 ,探讨了固相聚合的机理。