Effects of peel angle on peel force of adhesive tape from soft adherend

In the case of the peeling of adhesive tapes from soft adherends, the contributions of the compressive force at the adhered portion as well as the larger deformation of adherend have essential roles in determining the peeling properties. In this paper, the peel force of an adhesive tape from a soft adherend has been measured to understand the peeling mechanism, which is greatly affected by the peel angle. A commercially available pressure-sensitive adhesive was used as the tape, and a cross-linked polydimethylsiloxane (PDMS) was used as the soft adherend. The purpose of this study is to clarify the effects of the peel angle on the peel behavior of this system at room temperature under different material specifications and different experimental conditions. The factors that affect the peel force of the PDMS adherend included the degree of cross-linking in PDMS, the thickness of PDMS, peel angle, and peel velocity. Two characteristic peel patterns were observed, which depended on the material specifications and different experimental conditions. The peel mechanism was discussed in terms of the deformation of the adherend.     

Synthesis of pH Sensitive Organic-Inorganic Polymer Hybrids

Summary The synthesis of pH sensitive organic-inorganic polymer hybrids from poly(2-hydroxyethyl methacrylate) derivatives and alkoxysilane is described. To a reaction mixture of poly(2-hydroxyethyl methacrylate) derivatives, tetramethoxysilane, 2,7-bis(carboxyethyl)-4- or 5-carboxyfluorescein (BCECF) as a fluorescent probe, and ten equivalents of HCl aqueous solution in methyl ethyl ketone / propanol (7/3, v/v) were added. The resulting mixture was kept stirring at room temperature for 1 h and was heated at 40 °C for 2 weeks. The changes of the pH were estimated as changes in the fluorescence intensity with the pH sensitive fluorescence probe BCECF trapped within the obtained polymer hybrid. Consequently, the pH value was found to be proportionate to the fluorescence intensity.     

EXTRACTION OF HEAVY METAL IONS WITH 3-[(DIOCTYLAMINO)METHYL]ALIZARIN

3-[(Dioctylamino)methyl]alizarin (C₈AL), which is endowed with high solubility in nonpolar organic solvents through introduction of dioctylaminomethyl group into the alizarin nucleus was studied for extracting heavy metal ions such as Cu(II), Zn(II), Cd(II), Co(II), Mn(II), and Ni(II), from aqueous solution.Cu(II) was most readily extracted into chlorobenzene at low pH and thus was separated from other metal ions. The metal ions stabilized in alkaline solution in the presence of water-soluble chelating agents were found to be extracted by this, alizarin-type extraction agent into chlorobenzene with the assistance by lipophilic quaternary ammonium salt, Capriquat? (methyltrioctylammonium chloride, Q^?C1^?).The proton dissociation process of CRAL was studied, and the mechanism of these metal extractions was discussed.The separation of Cu(II) and Ni(II) from the mixture with other divalent metal ions was also studied.     

Kinetics of the thermo-oxidative and thermal cracking reactions of Athabasca bitumen

The thermo-oxidative and thermal cracking reactions of Athabasca bitumen were examined qualitatively and quantitatively using differential thermal analysis (DTA). Reaction kinetics of low temperature oxidation (LTO) and high temperature cracking (HTC) were determined. The rate of the LTO reaction was found to be first order with respect to oxygen concentration. The activation energy and the Arrhenius pre-exponential factor were 64 MJ kg^?1 mol^?1 and 10^5.4 s^?1, respectively. The effects of atmosphere, pressure, heating rate and support material on the thermal reactions of bitumen were studied. In general, it was found that partial pressures of oxygen > 10% O₂ favoured exothermic oxidation reactions. High pressure increased the rates of LTO and HTC as well as the exothermicity of these reactions. A major contribution of this study to thermal in-situ processes is that heating rate can be used effectively to control the extent of low temperature oxidation and hence fuel availability during in-situ combustion. Low linear heating rates (2.8 °C min^?1) favoured low temperature oxidative addition and fission reactions. The reaction products readily formed coke and combusted upon heating. High linear heating rates (24.5 °C min ^?1) led to rapid oxidation reactions in the high temperature zone; the high temperature and the energy released during oxidation appeared to promote combustion. Finally, when sand was used as the support material there appeared to be a catalytic effect in both LTO and HTC reactions.     

Synthesis of through-space conjugated polymers containing the pseudo-<Emphasis Type="Italic">ortho</Emphasis>-linked [2.2]paracyclophane moiety

New through-space conjugated polymers comprising the pseudo-ortho-linked [2.2]paracyclophane moiety were synthesized by the Sonogashira coupling reaction. All the synthesized polymers were soluble in common organic solvents and could form thin films. The UV–vis absorption spectra of the synthesized polymers revealed an extension of the conjugation length owing to the through-space interactions. The polymers exhibited a blue-light emission in both solution and film states.     

Through-space conjugated polymer containing [2.2]paracyclophane and dithiafulvene units in the main chain

A new through-space conjugated polymer containing alternate [2.2]paracyclophane and dithiafulvene units was synthesized by cycloaddition polymerization of aldothioketene derived from 4,16-diethynyl[2.2]paracyclophane. The obtained polymer was soluble in common organic solvents and could form thin films. UV–vis absorption spectrum of the polymer revealed that its conjugation length increased due to the through-space interaction of the [2.2]paracyclophane units. The polymer formed a charge transfer (CT) complex with 7,7,8,8-tetracyanoquinodimethane (TCNQ) in DMSO.     

Development of high performance,waterborne coatings. Part I: Emulsification of epoxy resin

A new manufacturing process of high performance, waterborne coatings for can coating applications is developed, which includes emulsification of an epoxy resin with or without its hardener by incorporation of an acrylic resin. It becomes possible by this new process to emulsify a variety of resins with minimum effects of the surfactant acrylic resin. Thus, latitude to design formulations is widened and the performance of epoxy resin and its hardener can be fully developed.