Izvorni znanstveni članak
A Study of Residual Benzoyl Peroxide in Poly (methyl methacrylate) Resins by Gas Chromatography
Ante Omrčen
; Nova bolnica Zagreb, Zagreb, Hrvatska
Vjekoslav Jerolimov
; Stomatološki fakultet Sveučilišta u Zagrebu, Zagreb, Hrvatska
Anđa Alajbeg
; INA - razvoj i istraživanje Zagreb, Hrvatska
Sažetak
The aim of this study was to assess differences in the findings of residual benzoyl peroxide and the value of gas chromatography in the quantification of residual benzoyl peroxide in poly (methyl methacrylate) resins. Acrylate preparations obtained by heat polymerization o f four poly (methyl methacrylates), i.e. Futur aery I
2000 (Schuetz-Dental), Poli-Dent K-30S (Polident), Stelon LP (Galenika) and Biocryl-R (Galenika), were used in the study. All the four materials were polymerized by three different procedures of polymerization: a) short-term, 30 min at 70°C and 30 min at 100°C; b) medium-term, 2 h at 70°C and 1 h at 100°C; and c) longterm, 7 hat 70°C and 3 h atl00°C. All the three procedures of polymerization
were performed in an automated KaVo, type EWL- 5518 device for polymerization (Leutkirch, Germany). The preparations were crushed into fragments and dissolved in methylene chloride. The amount o f residual benzoyl peroxide was determined by gas chromatography on a Pye Unicam 304 instrument (Cambridge, UK). Results o f the study o f residual benzoyl peroxide in polymerisates showed the values to be on a steady decline from the short-term to the long-term procedure. No statistically significant differences were observed either in the findings of residual benzoyl peroxide among the four different preparations or among the three polymerization procedures employed. Due to its reactivity, gas chromathography failed to be proved as a reliable procedure for quantitative determination o f benzoyl peroxide.Comparison o f the results of this study with those obtained by some of the so-called »cold« methods (e.g., infrared spectrophotometry or ultraviolet spectrophotometry) might produce interesting information.
Ključne riječi
residual benzoyl peroxide; heat-polymerizing acrylates; gas chromatography
Hrčak ID:
100552
URI
Datum izdavanja:
15.12.1993.
Posjeta: 1.584 *