Adhesive interphase analyses of isotactic polypropylene and cyanoacrylate with cobalt complex primers

Abstract

The modification of surface properties of isotactic polypropylene (it.PP) has attracted much attention in fundamental science and industrial applications. Primer treatment is a promising methods that is employed to overcome the poor adhesive property of it.PP. In this study, we examined the primer effect of the cobalt complexes, cobalt (II) acetylacetonate Co(acac)2 and cobalt (III) acetylacetonate Co(acac)3, from the perspectives of adhesive strength, curing process, surface structure, affinity between substrate and adhesive, morphology and interfacial thickness.The results obtained explain the increased adhesive strength between an isotactic polypropylene substrate and a cyanoacrylate adhesive. In particular, the interfacial regions were evaluated as "interphase" by nano-Raman scattering microscopy and transmission electron microscope-energydispersive X-ray spectroscopy. The region is expanded by applying Co(acac)2 primer as the adhesive strength increased. The Co(acac)2 primer caused the increased adhesive property with the enhancement of molecular interaction, chemical affinity, and mutual diffusion.

Analyses of the Adhesion Interphase of Isotactic Polypropylene Using Hot-Melt Polyolefin Adhesives

“…These results suggested the correlation between T-peel strengths and interphase thicknesses. We have previously reported on the dependence of T-peel strength on interphase thickness and primer treatment . In this work, as the similar relation between T-peel strengths and interphase thicknesses without any primer treatment was observed, we suspected that the morphology and molecular behavior in the interphase region would have a large effect on their adhesive properties.…”

“…The adhesive properties were decided by various factors including surface roughness of the adhered substrates, difference of surface free energies between substrates and adhesives, mechanical properties of adhesives and substrates, and adhesion interfacial structure. We also have previously reported on the correlation between adhesive strength and interfacial thickness of the isotactic polypropylene ( it .PP)/cyanoacrylate ester instant adhesives using a confocal Raman scattering microspectroscope . It is clarified that the primer treatment to it .PP substrates with cobalt complex primers provided a larger adhesive strength as well as a larger thickness of interfacial regions.…”

“…The boundary region between different materials is called as interface or interphase. − The former, “interface”, is used when the boundary can be considered as a two-dimensional plane. On the contrary, the latter, “interphase”, regard the boundary as a three-dimensional layer.…”

“…Recent drastic developments of the instruments for interfacial analyses and inspection have revealed not only the structure and properties of the interphase but also molecular behaviors of the polymer chains at the interphase. There are various candidates of instruments for the precise analyses of the interphase, for example, transmission electron microscope (TEM), ,− atomic force microscope (AFM), − confocal Raman scattering microspectroscope, ,,− AFM-infrared spectroscope (AFM-IR), − sum frequency generation (SFG) vibrational spectroscope, − X-ray photoelectron spectroscope (XPS), − neutron reflectometer (NR), − X-ray absorption fine structure (XAFS) measurement, , Rutherford scattering measurements, − and so on. These advanced analysis technologies provide the information at the interphase including nanostructure, molecular orientation, distribution, and chemical bond states.…”

Development of ternary-component mixed-matrix membranes for advanced gas separations

“…The result showed that the synthesized samples were mostly irregular, with a particle size of less than 100 nm. For the case of Co(acac) 3 , the observation with SEM was not possible due to its magnetic nature as reported in previous work [95]. The porosity properties of SNW-1 nanoparticles were measured using N 2 physisorption at 77 K. In general, the SNW-1 sample demonstrates a property typical of microporous materials with type 1 isotherms, where high N 2 sorption was observed in a low-pressure region (Figure 4-4(a)).…”