Improved Color Stability Research Articles

A new radiochromic dosimeter film

By employing acid-sensitive leuco dyes in a chlorine-containing polymer matrix, a new radiochromic dosimeter film has been developed for gamma, electron beam, and ultraviolet radiation. These dosimeter films undergo a color change from colorless to royal blue, red fuchsia, or black, depending on dye selection, and have been characterized using a visible spectrophotometer over an absorbed dose range of 1 to 100 kGy. The primary features of the film are improved color stability before and after irradiation, whether stored in the dark or under artificial lights, and improved moisture resistance. The effects of absorbed dose, dose rate, and storage conditions on dosimeter performance are discussed. The dosimeter material may be produced as a free film or coated onto a transparent substrate and optionally backed with adhesive. Potential applications for these materials include gamma sterilization indicator films for food and medical products, electron beam dosimeters, and in-line radiation monitors for electron beam and ultraviolet processing.

石炭液化油の劣化と安定化 ＩＩＩ 石炭液化油の色相安定性と相溶性

Coloration and compatibility with commercial gas oil have been studied on raw coal-derived liquid and three kinds of hydrotreated oils. Following results have been obtained:(1) Irradiation of coal-derived liquid accelerated coloration significantly.(2) Oxidation of coal-derived liquid caused coloration. High boiling range fraction showed stronger coloration than low boiling range fraction.(3) The extent of coloration correlated well with the content of nitrogen in oils.(4) Hydrotreating of coal-derived liquid improved color stability.(5) The coal-derived liquid suppressed the oxidation of a-methylstyrene and reac-ted with galvinoxyl, the extent being more significant for liquid with higher nitrogen content.(6) Compatibility of raw coal-derived liquid with commercial gas oil was deterio-rated by oxidation.

Production d'un cidre rose stable

AbstractWe have optimized the efficiency of extraction of anthocyanin pigments from the pulp of Mclntosh apples, using a solution of tartaric acid and bisulfite at 55° C. The extracted and concentrated pigments were added to cider(apple-wine) and subjected to stability tests at different storage temperatures, light exposures, pH and various concentrations of added antioxidants such as ascorbic acid or bisulfite.Apple pigments were more stable when stored at low temperatures and in the dark; moreover a decreasing acid pH (5.0 to 1.0) favored a better stability. Addition of SO2 (50-300 mg/l) as an antioxidant did not result in a better stability (significant at p < 0.05) when compared to control samples. However, improvement in color stability up to 50 days was obtained with the addition of 200-300 mg/l of ascorbic acid.

EFFECT OF MICROWAVE BLANCHING ON THE COLOR AND COMPOSITION OF STRAWBERRY CONCENTRATE

ABSTRACTThe influence of native enzymes on the color and composition of strawberry juice and concentrate was investigated through analyses of juice and concentrate which had been made from microwave‐blanched and from unheated fruit. Changes in anthocyanin (ACN) pigment, leucoanthocyanins, flavanols, total phenolics, ascorbic acid, and dehydroascorbic acid were monitored during 8 wk storage at 20°C; Hunter color parameters, polymeric color, and browning were also measured. Blanching results in improved color stability and has a protective effect on ACN pigments, reactive phenolics, and ascorbic acid. Blanched strawberry concentrate browns slower than the control. Monomeric ACN pigment undergoes rapid degradation to form polymeric pigments which are resistant to bisulfite bleaching.

Light stabilization of flame retardant impact polystyrene

AbstractThis paper presents the results of a study onn the effectiveness of ultraviolet absorbers and light stabilizers in preventing the discoloration of flame retardant impact polystyrene. The deleterious effect of certain flame retardants, i.e., aromatic or aliphatic halogenated compounds, on the light stability of this polymer is shown. Light stabilizer systems resulting in substantially improved color stability during light exposure are presented. The beneficial effect df co‐additives, including antioxidants, acid acceptors, epoxies, phosphites, and thiosynergists, on light stability is also discussed.

Improved Colorimetric Determination for Furfural in Citrus Juices

Abstract An improved colorimetric method for furfural in citrus juices, which is based on the well known aniline-acetic acid reaction with furfural (Stenhouse reaction), is described. Addition of SnCl2 and HCl yielded higher intensity and improved color stability. The reagent giving the best results contained 1% SnCl2, 0.6N HCl, and 10% aniline in glacial acetic acid.

Diminishing Discoloration in Methacrylate Accelerator Systems

To improve color stability in methacrylate accelerator systems, a comparison was made of systems of chemical compounds used in the polymerization of methacrylate monomers at room temperature. This paper reports the tendency of these compounds to form discolored products.

Hexyl Acetate Improves Color Stability of Urethane Coatings

Hexyl Acetate Improves Color Stability of Urethane Coatings