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At the request of the US EPA Oil Program Center, the National Exposure Research Laboratory's Ecosystems Research Division (ERD) in Athens is developing an oil spill model that focuses on fate and transport of oil components under various response scenarios. A database of prototype oils for use in models is necessary. This multiple component composition data, however, is not typically available because of complexity of oil composition and the impossibility of immediate characterization in the event of a spill. Thus the creation of a database containing both physical property and chemical composition data for a number of common oils at various weathering percentages is highly desirable. The data set must be based upon fractionation of the oils into groups of compounds with similar structures and properties and further must reflect the changes to the oil over the course of the spill. Since 1984, the Emergencies Science and Technology Division (ESTD) of Environment Canada (EC) has developed a database on various physical and chemical properties of crude oils and petroleum products. Through many years endeavour, the database now contains information of hundreds of oils from all over the world. In 2002, funded by the US EPA and EC, the ESTD and ERD completed the cooperative project “Development of a Composition Database for Selected Multicomponent Oils,” to characterize ten prototype crude oils and refined petroleum products. The present work, Oil Composition and Property Database for Oil Spill Modeling, is a logical extension of the 2002 project. Nine new crude oils in common use and with potential to be spilled in the US waters were selected for inclusion in the model database. Comprehensive physical property measurement and chemical composition characterization have been performed for these oils at four weathered stages of each oil. This project provides the most complete and comprehensive database for the selected oils to date. The new composition data has been integrated into the existing US EPA and EC oil properties database. The results are made available to the public on the world wide web.

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SynopsisA rapid method for determining the molecular weight distribution of polymers has been the aim of polymer chemists for a long time. The method presented here requires less tban two hours, including dissolution of the polymer. It is an exteneion of a photoelectric turbidimetric technique presented by Taylor and Tung in 1961. The equipment has been completely redesigned and presently consists of a copper block containing a turbidity cell, optical system and attendant electronic circuitry for measuring relative changes in turbidity of polymer solutions aa a function of temperature. An X-Y recorder is used t o plot turbidity versus temperature. A parameter determined from the plot is correlated with a meaaure of molecular weight distribution determined on known samples for each type polymer by another means. Baaed on this correlation unknown samples may be analyzed. The instrument is eaay t o operate and has shown excellent stability over a two year period. Polymers studied by this technique include ethylene-propylene copolymer (EPR), polypropylene, polyethylene, and butyl, however, the only results to be reported here are those on ethylene-propylene copolymer.

10 min., the addition of methanol produced a soft, translucent precipitate which on further washing with methanol gave an opaque and somewhat harder material. This was dried in a vacuum oven to give a Soy0 yield of a white solid soluble in water as well as in methylene chloride. In water the polymer had an inherent viscosity (In qrel/c at 0.5% concentration) a t 30°C. of 0.33. In methylene chloride the inherent viscosity was 0.69.The polymer became molten on a hot bar at around 280°C., and showed excellent thermal and oxidative stability up to this temperature. Films which were drawable could bc cast from methylene chloride solution.Trcatrnent of p-dioxene with 0.25y0 azobisisobutyronitrile as a potential initiator a t 56OC. for 49 hr. gave no polymer. The monomer thus behaved as a typical vinyl ether, polymerizing readily by a cationic but by not a free radical mechanism.