Open AccessPALS probing of photopolymerization shrinkage in densely packed acrylate-type dental restorative composites
Author(s) -
Olha Shpotyuk,
Adam Ingram,
O. Shpotyuk,
Andrii Miskiv,
Nina Smolar
Publication year - 2020
Publication title -
polimery w medycynie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.129
H-Index - 11
eISSN - 2451-2699
pISSN - 0370-0747
DOI - 10.17219/pim/118394
Subject(s) - materials science , composite material , photopolymer , polymerization , polymer , composite number , positron , acrylate , electron , nuclear physics , copolymer , physics
Using positron annihilation lifetime spectroscopy (PALS), microstructural changes in commercial dental restorative composites under light-curing polymerization were identified as a modification in mixed positron/Ps trapping, where the decay of positronium (Ps; the bound state of positrons and electrons) is caused by free-volume holes mainly in the polymer matrix, and positron trapping is defined by interfacial free-volume holes in a mixed filler-polymer environment. In loosely packed composites with a filler content of <70-75%, this process was related to the conversion of Ps-to-positron trapping.