Simultaneous Measurement of Polymerization Stress and Curing Kinetics for Photo-polymerized Composites with High Filler Contents
Zhengzhi Wang, Forrest A. Landis, Anthony A. Giuseppetti, Sheng Lin-Gibson, Martin Chiang
Objectives. Photopolymerized composites are used in a broad range of applications with their performance largely directed by reaction kinetics and contraction accompanying polymer-ization. The present study was to demonstrate an instrument capable of simultaneously collecting multiple kinetics parameters for a wide range of photopolymerizable systems: degree of conversion (DC), reaction exotherm, and polymerization stress (PS). Methods. Our system consisted of a cantilever beam-based instrument (tensometer) that has been optimized to capture a large range of stress generated by lightly-ﬁlled to highly-ﬁlled composites. The sample conﬁguration allows the tensometer to be coupled to a fast near infrared (NIR) spectrometer collecting spectra in transmission mode. Results. Using our instrument design, simultaneous measurements of PS and DC are per-formed, for the ﬁrst time, on a commercial composite with ≈80% (by mass) silica particle ﬁllers. The in situ NIR spectrometer collects more than 10 spectra per second, allowing for thorough characterization of reaction kinetics. With increased instrument sensitivity cou-pled with the ability to collect real time reaction kinetics information, we show that the external constraint imposed by the cantilever beam during polymerization could affect the rate of cure and ﬁnal degree of polymerization. Signiﬁcance. The present simultaneous measurement technique is expected to provide new insights into kinetics and property relationships for photopolymerized composites with high ﬁller content such as dental restorative composites.
, Landis, F.
, Giuseppetti, A.
, Lin-Gibson, S.
and Chiang, M.
Simultaneous Measurement of Polymerization Stress and Curing Kinetics for Photo-polymerized Composites with High Filler Contents, Composites Science and Technology, [online], https://doi.org/10.1016/j.dental.2014.09.006
(Accessed July 5, 2022)