Volumetric effects in the degradation of dimethacrylate-based polymer/filler nanocomposites: A positron annihilation study

被引：10

作者：

Shpotyuk, Oleh ^{[1
,2
]}

Ingram, Adam ^{[3
]}

Shpotyuk, Yaroslav ^{[4
,5
]}

Filipecki, Jacek ^{[1
]}

Shpotyuk, Olha ^{[6
]}

机构：

[1] Jan Dlugosz Univ Czestochowa, Fac Sci & Technol, 13-15 Armii Krajowej Str, Czestochowa 42200, Poland

[2] Vlokh Inst Phys Opt, Dept Opt Glass & Ceram, 23 Dragomanov Str, Lvov 79005, Ukraine

[3] Opole Univ Technol, Dept Phys, 75 Ozimska Str, Opole 45370, Poland

[4] Univ Rzeszow, Inst Phys, 1 Pigonia Str, Rzeszow 35959, Poland

[5] Ivan Franko Natl Univ Lviv, Dept Sensor & Semicond Elect, 1 Univ Ska Str, Lvov 79000, Ukraine

[6] Danylo Halytsky Lviv Natl Med Univ, 69 Pekarska Str, Lvov 79010, Ukraine

来源：

POLYMER DEGRADATION AND STABILITY | 2020年 / 176卷

关键词：

Degradation; Polymer/filler nanocomposites; Volumetric effects; Positron annihilation lifetime spectroscopy; Photopolymerization; Physical ageing; Light curing; LIFETIME; SPECTROSCOPY; TEMPERATURE; POLYCARBONATE; IRRADIATION; DEPENDENCE; DEFECTS; GLASSES; SIZE;

D O I：

10.1016/j.polymdegradstab.2020.109150

中图分类号：

O63 [高分子化学（高聚物）];

学科分类号：

070305 ; 080501 ; 081704 ;

摘要：

The applicability of positron annihilation lifetime (PAL) spectroscopy to identify volumetric changes in nanostructured polymer/filler substances is first verified at the example of commercially available dimethacrylate-based dental restorative composites Charisma (R) (Heraeus Kulzer GmbH, Germany) affected to light-curing photopolymerization and one-year dry physical ageing. Principal channel governing PAL spectra in these nanocomposites is recognized as mixed positron-Ps trapping, where positronium Ps (i.e. bound positron-electron state) decay occurs in free-volume holes localized preferentially in polymer matrix, while free positron self-annihilation is character for interfacial voids at the surface of filler-particles assemblies in the filler and/or mixed filler-polymer environment. Methodological algorithm for experimental PAL spectra refinement referred to as the x3-x2-CDA (coupling decomposition algorithm) is validated for these nanocomposites, obeying changes in atomic-deficient structure due to direct conversion between positron-trapping and Ps-decaying sites. Straightforward parameterization of the reconstructed PAL spectra allows meaningful identification of free-volume entities responsible for nanostructurization-driven transformations. (C) 2020 Elsevier Ltd. All rights reserved.

引用

页数：10

共 39 条

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