Positronium lifetime measurements and the thermal degradative behaviour of polyvinyl chloride

Abstract Investigations of the effect of the excitation light wavelength on the intensity distribution in the fluorescence band of 1,4-diphenyl-1,3-butadiene (DPB) in poly(vinyl alcohol) films (PVA) at 296 and 87 K for samples before and after heating to 423 K, and fluorescence lifetime measurements have shown that trans-trans and cis-trans conformers are responsible for the emission of fluorescence. The fluorescence properties of the DPB sample in PVA heated to 423 K were found to be similar to those of DBP in polyvinyl chloride and polyvinyl formal at 296 K.

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Positronium lifetime measurements in micro- and mesoporous ferrisilicates

Radiation Physics and Chemistry ◽

10.1016/j.radphyschem.2017.05.012 ◽

2017 ◽

Vol 139 ◽

pp. 49-54

Author(s):

Trần Quốc Dũng ◽

Károly Lázár

Keyword(s):

Lifetime Measurements ◽

Positronium Lifetime

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Effect of Hydrophilicity of the Sidechains on the Amorphous Structure of Polypropylene Derivatives Studied by Positronium Lifetime Measurements

Materials Science Forum ◽

10.4028/www.scientific.net/msf.733.159 ◽

2012 ◽

Vol 733 ◽

pp. 159-162 ◽

Cited By ~ 1

Author(s):

K. Ito ◽

Hideaki Hagihara ◽

Yoshinori Kobayashi

Keyword(s):

Mechanical Property ◽

Significant Contribution ◽

Amorphous Region ◽

Amorphous Structure ◽

Segmental Motion ◽

Interchain Interaction ◽

Lifetime Measurements ◽

Positron Annihilation Lifetime ◽

Positronium Lifetime ◽

Free Volume Hole

Polypropylene (PP) derivatives, prepared with different α-olefin comonomers of hexane and hexenol, were investigated using the positron annihilation lifetime technique. The free-volume hole sizes for the present polymers were quantified from the long-lived ortho-positronium (o-Ps) lifetimes. In contrast to the case of nonpolar, introduction of the polar hexenol into PP reduced the o-Ps lifetimes and the hole sizes derived from them. This indicates that the interchain interaction due to the hydrogen bonds in the amorphous region is much stronger than the enhancement of the segmental motion due to the butyl long branch. A comparison of the o-Ps lifetimes with the corresponding tensile strength suggested significant contribution of the subnanostructure in the amorphous region to the mechanical property.

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A Replica Technique for the Inside Surfaces of Small Diameter Pipes and Tubes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010006177x ◽

1967 ◽

Vol 25 ◽

pp. 352-353

Author(s):

T. G. Gregory

Keyword(s):

Polyvinyl Chloride ◽

Small Diameter ◽

Replica Technique ◽

Tube Size ◽

Inside Diameter ◽

Complete Inspection ◽

Operating Limits

A nondestructive replica technique permitting complete inspection of bore surfaces having an inside diameter from 0.050 inch to 0.500 inch is described. Replicas are thermally formed on the outside surface of plastic tubing inflated in the bore of the sample being studied. This technique provides a new medium for inspection of bores that are too small or otherwise beyond the operating limits of conventional inspection methods.Bore replicas may be prepared by sliding a length of plastic tubing completely through the bore to be studied as shown in Figure 1. Polyvinyl chloride tubing suitable for this replica process is commercially available in sizes from 0.037- to 0.500-inch diameter. A tube size slightly smaller than the bore to be replicated should be used to facilitate insertion of the plastic replica blank into the bore.

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