Optically transparent bio‐based polyamides with microcellular foaming properties derived from renewable difunctional aminoamides

Crystal nucleating agent Bis (3, 4- dimethylbenzylidene) sorbitol (DMDBS) was used to tune the melt strength and microcellular foaming properties of isotactic polypropylene (iPP) in this study. Rheological testing results reveal that the introduction of DMDBS could enhance the storage modulus and complex viscosity of iPP, obviously increase its crystallization onset temperature, compared to its counterparts without DMDBS. The addition of DMDBS could also significantly increase the cell nucleating ability of iPP, due to its large surface, cooperating with a thermal history control treatment. Quite fine microcellular iPP/DMDBS foams were fabricated with relatively small average cell sizes of nano to several micrometers, and cell densities up to 1011∼1012 cells/cm3, using the synergy effect of DMDBS and iPP’s melt self-enhancement. Under a comparatively low re-saturation pressure of 8 to 12 MPa, ideal microcellular foams could be generated, at a temperature zone of 158 to 162°C, which is slightly below to iPP’s original pellets nominal melting point.

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Dislocations, Ordering and Antiferromagnetic Domains in MnO

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100069600 ◽

1970 ◽

Vol 28 ◽

pp. 522-523

Author(s):

D. J. Barber ◽

R. G. Evans

Keyword(s):

Electron Diffraction ◽

Single Crystal ◽

Optical Microscopy ◽

Defect Chemistry ◽

Magnetic Structures ◽

Optically Transparent ◽

Magnetic Features ◽

Antiferromagnetic Domains

Manganese (II) oxide, MnO, in common with CoO, NiO and FeO, possesses the NaCl structure and shows antiferromagnetism below its Neel point, Tn∼ 122 K. However, the defect chemistry of the four oxides is different and the magnetic structures are not identical. The non-stoichiometry in MnO2 small (∼2%) and below the Tn the spins lie in (111) planes. Previous work reported observations of magnetic features in CoO and NiO. The aim of our work was to find explanations for certain resonance results on antiferromagnetic MnO.Foils of single crystal MnO were prepared from shaped discs by dissolution in a mixture of HCl and HNO3. Optical microscopy revealed that the etch-pitted foils contained cruciform-shaped precipitates, often thick and proud of the surface but red-colored when optically transparent (MnO is green). Electron diffraction and probe microanalysis indicated that the precipitates were Mn2O3, in contrast with recent findings of Co3O4 in CoO.

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Functional surfaces produced by foam coating

TAPPI Journal ◽

10.32964/tj15.8.515 ◽

2016 ◽

Vol 15 (8) ◽

pp. 515-521 ◽

Cited By ~ 1

Author(s):

EIJA KENTTÄ ◽

HANNA KOSKELA ◽

SARA PAUNONEN ◽

KARITA KINNUNEN-RAUDASKOSKI ◽

TUOMO HJELT

Keyword(s):

Life Time ◽

Silica Coating ◽

Foaming Properties ◽

Coated Paper ◽

Paper Properties ◽

Foaming Agent ◽

Foaming Agents ◽

Size Stability ◽

Stability Measurement ◽

Standard Paper

This paper reports experiments on silica coating formulations that are suitable for application as a thin pigment layer with foam coating technique on a paper web. To understand the foaming properties of nanosilica dispersions, the critical micelle concentration, foam half-life time, and foam bubble size stability were determined with three different foaming agents. The results indicate that the bubble stability measurement is a useful characterization method for foam coating purposes. Pilot foam coating trials were done and the effects of the chosen foaming agents were studied on the properties of the nanosilica-coated paper. The surface hydrophilicity of silica coated paper was related not only to silica pigment, but also to the chemical nature of the foaming agent. Standard paper properties were not affected by the thin silica coating.

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