Recent trends of the market and technology in fluoroelastomers are reviewed. Fluoroelastomers have been increasingly used in a variety of application fields such as chemical, automotive, electric, machinery and energy related industries as the most reliable elastometric material. These expanding applications have concurrently stimulated the technology of fluoroelastomers to develop and improve such elastomers as vinylidene fluoride-hexa fluoropropylene, tetrafluoroethylene-propylene, perfluorinated, fluorosilicone, phosphazene, etc. exhibiting still enhanced heat, chemical, oil, low temperature resistances, through creating new polymer, modifying the composition, or introducing new vulcanization recipe.
The surface plasma treatments for fluorine-containing materials are summarized. The plasma-solid interactions are divided into two groups : the interaction of fluorocarbon polymers such as polytetrafluoroethylene, poly (vinyl fluoride), and poly (vinylidene fluoride) (PVdF) with plasmas of O2, He, Ar, etc., and the interaction of hydrocarbon polymers such as polyethylene and polypropylene with plasmas of F2, CF4, etc.. Particularly, the fluorination of polymers due to the latter interaction and changes caused in the surface properties are described in detail. A difference in the reactivity of PVdF and ethylene-propylene copolymer (EPDM) with CF4 and Ar plasmas is clarified using XPS data.
A great number of analytical techniques have been developed taking advantage of the marked specialities of fluorine compounds. This article surveys the successful applications of fluorine compounds to the designing of analytical reagents, methods, and separation techniques in recent years. Brief comments are also made on their features in terms of the basic properties of fluorine compounds.
The importance of microbial behavior of halogen-containing compounds, which are hardly decomposed by microorganisms, has been recognized in living systems. Especially, in fluorine chemistry, considerable attention has been focused on the search for chiral synthetic tools for the preparation of fluorinated bioactive molecules. In this review, we wish to outline the possibility of microbial transformation of fluorinated compounds under stereocontrol.
The reaction of 1, 2-epithiooctane with t-butylamine in a glass ampoule gave 1- (N-t-butylamino) -2-octanethiol (1) and 1- (N-t-butylaminomethyl) heptyl 2-mercaptooctyl sulfide (2). The ratio of (1) / [(1) + (2)] was high at the initial stage of the reaction, and decreased as the reaction proceeded. Excess t-butylamine caused no significant increase in the total yield. The addition of a small amount of alcohol promoted the reaction in a similar manner to the reaction of 1, 2-epithiooctane with secondary amine. (1) was concluded to be produced by a nucleophilic attack of t-butylamine on the terminal methylene of the ring of 1, 2-epithiooctane, and (2) to result from the reaction of the mercapto group of (1) with 1, 2-epithiooctane.
The Triglyceride (TG) Committee of the Japan Oil Chemists' Society (JOCS) participated in a collaborative study by the International Union of Pure and Applied Chemistry (IUPAC) for TG analysis by gas-liquid chromatography (GLC) using six samples provided by IUPAC : lard, butter fat, soybean oil, hydrogenated soybean oil, groundnut oil, and anhydrated butter fat. This study, based on the total acyl carbon number, was conducted by fifteen organizations of nine countries. A summary of the results obtained will be reported in this journal at this issue. Our committee determined the major TG molecular species in the samples using field desorption mass spectrometry (FD-MS), high performance liquid chromatography (HPLC) and the GLC of the collaborative study. The major molecular species in TG of lard, groundnut oil, and soybean oil were found to be palmito-oleo-linolein, mono-oleo-di-linolein and/or mono-palmito-di-linolein and mono-oleo-di-linolein, respectively. GLC, FD-MS, and HPLC analyses were found to provide significant information by which the major molecular species of TG in naturally occuring fats and oils could be estimated.
A simple rapid method for determination of nickel in hydrogenated oil was investigated. Extraction of nickel with hydrochloric acid instead of asking prior to the atomic absorption spectro-photometry was found suitable for routine analyses. A trace amount of nickel in hydrogenated oil could be sufficiently recovered by the following procedure : 20g of the oil were dissolved in 50100ml of carbon tetrachloride and then extracted three times with 50ml of 0.5N hydrochloric acid solution. Analytical results for several hydrognated oils obtained by this method agreed well with those by the JOCS method. This method may possibly be applicable to margarine and shortening present in various emulsifiers.
Hardened palm oil was found to deteriorate with an abnormal increase in acid value (AV) during storage. Therefore, a study was carried out to determine the causes of this and how to prevent it. 1) The increase in AV of hardened palm oil depended on the degree of hardening and storage temperature. The increase was marked when the oil had an iodine value of 1030 and contained more elaidic acid than oleic acid. Also it was more marked during storage at 25°C than that at 15°C or 37°C. 2) The addition of lipophilic sucrose fatty acid ester (SE-1) or soybean lecithin was effective for the most part in preventing deterioration. However, no effects were observed by the addition of monoglyceride or polyoxyethylene sorbitan fatty acid ester. 3) Hardened palm oil without emulsifiers storage at 25°C showed a rough crystal surface with a pile of irregular crystal size under scanning electron microscope. The surface of palm oil samples emulsified with SE-1 or soybean lecithin was smooth.