Impacts of impregnation with Timbercare Aqua on the red and yellow color tone of some woods and varnishes

This study has been performed for determining the effects of impregnation with Timbercare Aqua (Tc) on the red and yellow color tone of some woods and varnishes. For this purpose, the test samples prepared from Oriental beech, European oak, Scotch pine, Oriental spruce, and Uludag fir woods, which met the requirements of ASTM D 358, was impregnated with Tc according to ASTM D 1413 and producer's definition. After impregnation, wood surfaces have been coated by Sayerlack parquet varnish (Sp), Sayerlack interior varnish (Si), and Sayerlack exterior varnish (Se) varnishes in accordance with the ASTM D 3023 standards. According to ASTM D 2244, the red and yellow color tone of samples after varnishing process was determined. As a result, the value of red color tone was the highest in Oriental beech (15.21) and the lowest in Uludag fir (5.38). For the wood material, impregnation material, and varnish interaction, the red color tone value was the highest in Oriental beech + Tc + Sp (18.43) and the lowest in Uludag fir + Tc + Si (3.92). The value of the yellow color tone was the highest in pine (34.45) and the lowest in Oriental beech (26.50). For the wood material, impregnation material, and varnish interaction, the yellow color tone value was the highest in Oriental spruce + Tc + Sp (42.12) and the lowest in Oriental beech + Tc + Si (21.47). This effect may be due to the impacts of impregnation chemical on wood extractives and color pigments in varnish. Accordingly, it should be taken into care for applications where the red and yellow color tone value is important. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

New procedure to calculate the Hansen solubility parameters of polymers

The simplest experimental method to determine the Hansen solubility parameters (HSPs) for a polymer is to evaluate whether or not it dissolves in selected solvents. Those solvents dissolving the polymer will have HSPs closer to those of the polymer than those that do not. A computer program or graphical method can then be used to find the HSP for the polymer. In this work, an improved method for calculating the HSP of polymers, based on the Nelder–Mead optimization algorithm, is presented. The results of this program fit the data very well. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 31–36, 2007     

Acid-catalyzed moisture-curing polyurea/polysiloxane ceramer coatings

The para-toluene sulfonic acid (p-TSA) was used to catalyze the moisture curing of an organic/inorganic hybrid coating system. The organic phase was based on the isocyanurate of 1,6-hexamethylene of diisocyanate (HDI). The inorganic phase was based on the prepolymerized oligomers of tetraethyl orthosilicate (TEOS). An alkoxysilane-functionalized HDI isocyanate was added into the coating formulation to aid in phase miscibility. The general coating and tensile properties were evaluated as a function of the acid catalyst concentration. In addition, the films were analyzed using differential scanning calorimetry (DSC) and dynamical mechanical thermal analysis (DMTA). The results indicated that the acid catalyst enhanced the adhesive properties of the hybrid coatings. The addition of the acid catalyst increased the changed crosslink density of films and decreased the crystallinity of the organic phase.     

Study of oxidation after monoacrylate grafting on polyethylene

BACKGROUND: The surface properties of high‐density polyethylene and linear low‐density polyethylene were modified by grafting urethane monoacrylate monomer under UV irradiation. This graft polymerization was carried out on native substrates and on substrates pre‐treated by wet oxidation, for different oxidation times. RESULTS: As the urethane monacrylate layer is crosslinked, its grafting efficiency was checked by dissolving the polyethylene substrates in hot toluene. Grafting was evidenced by Fourier transform infrared spectroscopy of the obtained residues, which showed that both the characteristic urethane acrylate (3350 cm^?1) and polyethylene (2920, 730 and 720 cm^?1) bands were observable for any polyethylene oxidation time. For an oxidation time longer than 10 hours, acrylate grafting was homogeneous and the grafted surface was smooth with a roughness of less than 10 nm. In addition, X‐ray photoelectron spectroscopy analysis of the residues revealed that O/C had an average value of 0.19, which is lower than the value corresponding to pure acrylate (0.42), whereas N/C had an average value of 0.068, also lower than that of pure acrylate (0.09), thus confirming the grafting. CONCLUSION: A urethane monoacrylate layer was grafted on native and oxidized polyethylene films. For highly oxidized films, the grafted surfaces are smooth and homogeneous. Copyright © 2008 Society of Chemical Industry     

Interface optimization for poly silicon/tungsten gates

Novel dual work function (DWF) based transistors featuring low gate resistances are presented. The process discussed enables extremely fast array timings easily and is thus key to fulfilling the performance requirements for high performance DRAM chips. The key enabler of the advanced gate integration scheme and its properties is the understanding of tuning the interface contact resistance. The objective of this work was to systematically investigate the role of the interface between poly-Si and metal of DRAM gate structures focused on electrical data. Contact resistance values, speed and elemental analysis information summarize the main findings of the gate development and furthermore the stable control of the very thin film stack in high volume production.     

涂料涂装中的常见事故及安全预防

闸述了涂装涂料常见事故的原因、预防措施、解决办法及涂装施工现场的安全应急预案。     

PSt／PBA胶乳型互穿聚合物网络性质的研究

用乳液聚合技术制备了ＰＳｔ／ＰＢＡ胶乳型互穿聚合物网络，着重讨论了乳化剂、引发剂、交联剂及加料方式对其性能的影响。     

A quantitative study of blister growth on lacquered food cans by scanning acoustic microscopy

Scanning acoustic microscopy was used to image blistering of samples from food cans, internally coated with an epoxy-modified polyester lacquer, during exposure to aerated brine. Results were subjected to quantitative image analysis and have been discussed in the light of different models of blistering. The samples were taken from the side wall of the can, which had been formed by the draw-redraw process from pre-lacquered electro-chrome-coated steel sheet, thus providing insights into the effects of lacquer deformation.     

The Influence of the Laser Energy on the Thermal Diffusivity Evaluation of TBC by Laser Flash

Laser Flash is considered the standard technique for measuring the thermal diffusivity of solids. The interaction between TBC and the laser energy is studied because very low thermal effusivity and thermal diffusivity of TBC can produce very high temperature increase on the surface and temperature gradient within the sample. In such a case, microstructural modifications of TBC can be generated. In this work, such phenomena are studied experimentally on free standing TBC samples.     

Cyclic and Isothermal Oxidation at 1,100 °C of a CVD Aluminised Directionally Solidified Ni Superalloy

CVD aluminide coatings deposited on a Directionally Solidified (DS) substrate were oxidized at 1,100 °C up to 240 h under isothermal and cyclic oxidation conditions to study the growth mechanisms of the oxide scales and the possible degradation of the coatings. The specimens were investigated using light and scanning electron (SEM) microscopy, energy-dispersive spectrometry (EDS) and X-Ray Diffraction (XRD). The results indicate that the coatings provide a much greater beneficial effect under isothermal conditions than upon cycling. The cycled specimens undergo oxide-scale spallation and increased roughening, which can derive from growth and thermal stresses as well as from the NiAl → Ni₃Al phase transformation associated with Al depletion. Under isothermal conditions, typical oxide scales formed with the appearance of some rumples. However, the origin of rumpling is uncertain from these experimental results.