Zinc‐based compounds as smoke suppressant agents for an aerospace epoxy matrix

Smoke is considered to be the main hazard of fires involving epoxy resins but its production depends on many variables, principally the chemical character and the burning rate of the polymer plus the availability of oxygen. The work reported aimed to study the smoke suppressant effect and flammability performance of zinc‐based compounds (FR system) in epoxy matrix composites used in the aerospace and aeronautical industry. The flammability performance of neat and FR‐loaded systems was screened using microcombustion calorimetry, while smoke generation, in terms of carbon monoxide (CO) and carbon dioxide (CO₂) production, was analysed under dynamic conditions using cone calorimetry. Final results indicate that the dispersion of zinc borate and zinc hydroxystannate (ZHS) into epoxy matrices leads to a significant variation in flame retardant properties reducing both total heat release by about 25 and 30%, respectively, and heat release capacity by about 30 and 50%, respectively. The system containing ZHS shows an enhancement in all smoke suppressant properties; both tin compounds (zinc stannate (ZS) and ZHS) give a reduction of CO₂/CO ratio from 41 to 25 for ZS and from 41 to 36 for ZHS compared to neat matrix. Copyright © 2010 Society of Chemical Industry     

Laser repairing surface crack of Ni-based superalloy components

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｃａｓｔｎｉｃｋｅｌ ｂａｓｅｓｕｐｅｒａｌｌｏｙｉｓｔｈｅｍａｊｏｒｍａ ｔｅｒｉａｌｕｓｅｄｆｏｒｈｉｇｈｔｅｍｐｅｒａｔｕｒｅｃｏｍｐｏｎｅｎｔｓｏｆｔｈｅａｉｒｔｕｒｂｉｎｅｅｎｇｉｎｅ ,ｓｕｃｈａｓｖａｎｅ ,ｔｕｒｂｉｎｅｔｒａｙ ,ｃｏｍｂｕｓ ｔｏｒ.Ｕｓｕａｌｌｙｔｈｅｒｅａｒｅｍｏｒｅｔｈａｎｏｎｅｔｈｏｕｓａｎｄｏｆｖａｎｅｓｉｎａｔｕｒｂｉｎｅ ,ｓｏａｌａｒｇｅａｍｏｕｎｔｏｆｓｕｃｈｋｉｎｄｏｆｍａｔｅｒｉａｌｍｕｓｔｂｅｎｅｅｄｅｄ .Ｔｈｅｖ…     

ORDERING TRANSITIONS IN LIQUID CRYSTALS PERMIT IMAGING OF SPATIAL AND TEMPORAL PATTERNS FORMED BY PROTEINS PENETRATING INTO LIPID-LADEN INTERFACES

Recent studies have reported that full monolayers of L-α-dilaurylphosphatidylcholine (L-DLPC) and D-α-dipalmitoylphosphatidylcholine (D-DPPC) formed at interfaces between thermotropic liquid crystals (LCs) and aqueous phases lead to homeotropic (perpendicular) orientations of nematic LCs and that specific binding of proteins to these interfaces (such as phospholipase A ₂ binding to D-DPPC) can trigger orientational ordering transitions in the liquid crystals. We report on the nonspecific interactions of proteins with aqueous-LC interfaces decorated with partial monolayer coverage of L-DLPC. Whereas nonspecific interactions of four proteins (cytochrome c, bovine serum albumin, immunoglobulins, and neutravidin) do not perturb the ordering of the LC when a full monolayer of L-DLPC is assembled at the aqueous-LC interface, we observe patterned orientational transitions in the LC that reflect penetration of proteins into the interface of the LC with partial monolayer coverage of L-DLPC. The spatial patterns formed by the proteins and lipids at the interface are surprisingly complex, and in some cases the protein domains are found to compartmentalize lipid within the interfaces. These results suggest that phospholipid-decorated interfaces between thermotropic liquid crystals and aqueous phases offer the basis of a simple and versatile tool to study the spatial organization and dynamics of protein networks formed at mobile, lipid-decorated interfaces.     

In‐line optical techniques to characterize the polymer extrusion

In the past 15 years our research group has been creating new optical devices to characterize in real time the extrusion process. These detectors are made of a slit‐die fitted at the extruder exit from where the molten polymer flows, with a pair of transparent windows that allows a light beam to pass orthogonally through the molten flow. Following the reduction of the transmitted light intensity one is able to quantify the turbidity, which is a function of the type, concentration and particle size and shape of the second phase present in the flow. By evaluating the scattering pattern of a laser beam (LALLS) it is possible to get information upon the morphology of the molten polymeric system in real time during the extrusion. With the interposition of a pair of crossed polarizers in the optical beam, rheo‐polarimetry, it is possible to evaluate quantitatively the flow birefringence, which is a function of the degree of the polymer matrix orientation. POLYM. ENG. SCI., 54:386–395, 2014. © 2013 Society of Plastics Engineers     

Electrochemical and structural characterization of copper recycled from anodes of spent Li-ion batteries

In this study, the charge efficiency, nucleation growth, and morphology of electrodeposited copper from spent Li-batteries were studied. The charge efficiency for these deposits shows a maximum value of 99.41%, under a charge density of 5.0 C cm^?2. Studies with the SEM technique at pH 2.0 show well-formed nuclei. At pH 4.5, the deposits take the form of dendrites. XRD analysis shows that, in both cases, a Cu₂O structure is present, but with a large amount at pH 4.5, evidenced by peaks of [002] and [110] directions.     

Peel Adhesion of Poly(Vinyl Chloride) to Nitrile Rubbers

In addition to molecular interaction and physical entanglement of the molecular chains across the interface in poly (vinyl chloride)-nitrile rubber joints, at high temperatures and long contact times interfacial chemical bonds may be formed which seem to couple the two adherends thereby resulting in cohesive failure of the rubber matrix on peeling. This is verified by performing the peel tests at high temperatures, low peel rates and under swollen conditions. Infrared spectroscopic studies of the PVC/NBR blend reveal the formation of chemical bonds at the contact temperatures studied. The peel fracture energy is found to depend on the acrylonitrile content and presence of carboxylic content in the NBR, and the presence of stabilizer and plasticizer in the PVC phase, in addition to the molding and testing conditions.     

Are high resolution resistometric methods really useful for the early detection of electromigration damage?

In this paper the use of High Resolution Resistometric Techniques for early detection of electromigration strength of Al---Cu/TiN/Ti stripes is analyzed. Two lots of 4 μm wide lines were tested obtaining largely different lifetimes. When comparing the early resistance changes, at a first sight a similar behaviour was detected in the two lots. However, a more accurate inspection of the resistance evolution revealed the presence of two distinct and subsequent stages. Significant differences were detected during the first stage only, lasting a few hours. If confirmed by extensive experiments, this result could open new perspectives for the early detection of the metal quality.     

脉冲吹灰器在催化裂化装置余热锅炉上的应用

本文针对中国石油哈尔滨石化公司三催化装置CO余热锅炉存在的各换热面积灰严重的问题,介绍了脉冲吹灰装置应用后的实际效果,并对吹灰器使用过程中存在的部分问题提出了建议。