聚丙烯抗静电改性的研究进展

综述了近年来国内外提高PP抗静电性能方法的研究进展,包括抗静电剂涂敷法、抗静电剂内加法、导电材料添加法、抗静电剂复合法。最后展望了PP抗静电改性的发展趋势。     

邢钢降低冶金粉灰CaO平均极差的生产实践

邢钢白灰车间日供烧结工序最大粉灰量约为400t,是烧结工序最主要的粉灰供户。担负着为烧结提供优质熔剂的重任。自产冶金粉灰质量的好坏将直接制约烧结生产,影响烧结矿碱度的稳定和固体燃料的消耗,进而影响高炉的顺行程度,最终影响高炉的生铁成本和质量。针对冶金粉灰CaO极差波动较大,制定了改进措施,并取得了显著的效果。     

毒重石作水泥混合材的研究

结合毒重石质量优、易加工、生产成本低及吸收X射线、γ射线等特点,制备了以普通硅酸盐水泥熟料为主要原料,毒重石作水泥混合材,辅以适量石膏的水硬性胶凝材料。考察了毒重石掺量对水泥标准稠度用水量、凝结时间、安定性、不同龄期机械强度以及辐射屏蔽能力的影响。结果表明：毒重石对普通硅酸盐水泥熟料具有一定的缓凝作用;毒重石本身参与水化的能力很差,在水泥中基本上是作为非活性掺和材料,主要起填料的作用;毒重石水泥具有一定的辐射屏蔽能力,且随着毒重石掺量的增加,水泥的屏蔽效果增强。     

Effects of lithium perchlorate on poly(ethylene oxide) spherulite morphology and spherulite growth kinetics

Effects of lithium perchlorate (LiClO₄) on the crystallization behaviors of poly(ethylene oxide) (PEO) were investigated by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), and polarized optical microscopy (POM) in PEO/LiClO₄ system. DSC results indicate that there are nucleation effects of LiClO₄ on the crystallization of PEO. But, on the other hand, the coordination of lithium ion with the oxygen ether atoms of PEO can obviously reduce the crystallinity and spherulite growth rate of PEO. This contrary effect of LiClO₄ on the crystallization of PEO in PEO/LiClO₄ complexes system was analyzed and discussed in detail. The Laurizen–Hoffman theory was used to describe the Li‐coordinated crystallization kinetics of PEO spherulite. It showed that the nucleation constant (K_g) and folding surface free energy (σ_e) decreased with increasing LiClO₄ contents, and the energy necessary for the transport of segments across the liquid–solid interface (ΔE) increased on increasing the contents of LiClO₄. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis and Characterization of Poly[bis(ethyl salicylate)phosphazenes] and Poly[bis(ethyl salicylate diethylamino)phosphazenes] and Their Hydrolytic Degradation

The polydichlorophosphazenes were synthesized from hexachlorocyclotriphosphazenes by ring opening polymerization in the presence of AlCl₃ as a catalyst. Poly[bis(ethyl salicylate)phosphazenes] (PESP) and poly[bis(ethyl salicylate diethylamino)phosphazenes] (PESDEAP) were synthesized via macromolecular substitution reactions using ethyl salicylate and (or) diethylamine as side groups. The synthesis results were proved by nuclear magnetic resonance (¹H NMR, and ³¹P NMR) and gel permeation chromatography. In addition, the hydrolytic degradation of PESP and PESDEAP was investigated at constant temperature in neutral medium.     

低温甲醇洗系统贫富甲醇换热器泄漏原因分析及处理

介绍了晋煤天溪煤制油分公司低温甲醇洗系统贫富甲醇换热器的泄漏情况。分析了贫富甲醇换热器泄漏初期生产运行指标的异常现象和造成泄漏的原因,认为泄漏是不同物质对设备的腐蚀、冲刷造成的,并针对泄漏的具体情况,提出了不同的检修处理措施:管束泄漏量低于10%时,可采用焊接锲形堵头将泄漏列管两端进行封堵;管束泄漏量高于10%时,如换热器设计余量足,可将封头内部隔板取出,短接进出口;将换热管材质由10#钢换为06Cr19Ni10不锈钢。     

Free-standing one-dimensional plasmonic nanostructures

The field of plasmonics has become one of the most interesting and active research areas in nanotechnology, enabling numerous fundamental studies and applications. The ability to tailor the size, shape, and environment of metal nanostructures is the key component for controlling the plasmonic properties of individual or aggregated nanostructures. In this feature article, a category of chemically nanofabricated, unique free-standing one-dimensional (1D) plasmonic nanostructures has been summarized. The dispersible plasmonic nanostructures were obtained in high yield with control over gap size and feature size. This ability was exploited to tune the emerging plasmonic properties overcoming the difficulties of other methods to do so, leading to applications in analytical detection, biological sensing, and nanoelectronics.     

VAE／PVAc高固含量低粘度复合乳胶粘合剂

采用VAE为种子,半连续乳液聚合法制备VAE／PVAc复合乳液。用DSC和TEM分析结果表明在第二阶段聚合过程中,一次性加入乳化剂可获得大、小粒子共存在复合乳液,这种粒径分布有利于高固含量、低粘度乳液的制备。同时通过实验系统地考察了固含量、乳化剂、保护胶体和单体进料速度对乳液聚合的影响。采用这种以加宽粒径分布为目的的优化聚合工艺,制备出了一种稳定性好、粘接速度快且粘接力强的木材用高固含量低粘度白乳胶。     

祛蒜味牙膏的配方研究

通过选取儿茶酸、植酸钠等祛蒜味的有效成分和其他所需的原料,对祛蒜味牙膏的配方进行正交实验,利用模糊数学的方法对祛蒜味的有效性进行综合评价分析,选取出祛蒜味牙膏的合理配方。     

In situ reaction and solid solution induced hardening in (Ti,Zr)B2-(Zr,Ti)C composites

(Ti,Zr)B₂ - (Zr,Ti)C ceramics were synthesized by reactive hot-pressing and solid solution coupling effect using ZrB₂ and TiC powders as starting materials. Effects of sintering temperature on phase relations, microstructure and mechanical properties were reported. The equimolar ZrB₂ and TiC reactants ensured a complete in situ reaction to form (Ti,Zr)B₂ and (Zr,Ti)C solid solutions. The (Ti,Zr)B₂ - (Zr,Ti)C composite sintered at 1750°C was fully densified, and exhibited a high hardness of 29.1 GPa due to fine-grain hardening and solid solution hardening. The optimized comprehensive mechanical properties such as a hardness of 27.9 GPa, a strength of 705 MPa and an indentation fracture toughness of 5.3 MPa m^1/2 were achieved in (Ti,Zr)B₂ - (Zr,Ti)C composites sintered at 1800°C for 1 hour.