Additives and polymers can be made from corn

July lYY7

processing gives better plasticising, says Axon, with an automatic screen changer providing continuous filtering of impurities. Contact: Axon AB Plastics Machinery, S-265 39 korp, Sweden; tel: +46-42 570 80; fax: - 46-42 54152

NEW TECHNOLOGY Low-cost anti-shrinkage additive is claimed An inexpensive ‘one pot’ process for making a chemical additive which will help prevent shrinkage of hard polymers is claimed by the US National Institute of Standards and Technology (NIST). The additive is a special monomer (described as a ‘Spiro orthocarbonate’) which expands as it hardens. The first intended application is for polymer compounds for dental fillings, where the NIST researchers have produced composites of conventional dental monomers with the new additive, which exhibit very low shrinkage and good mechanical strength. It is suggested that the new monomers may also be usefir for making more reliable adhesive coatings and microelectronics packages. I bntact: Jeffrey Stansbury, A143 Polymer Bla’g, NIST Gaithersburg, MD 20899-0001, IJSA; tel: tmI-301 975 6790

Additives and polymers can be made from corn A new process to convert corn into a costefficient source of commercial chemicals, including additives and polymers, has been developed by researchers at the Argonne and other US Department of Energy (DOE) laboratories. The DOE group has signed a $7 million agreement with the Pennsylvania speciality chemicals company Applied CarboChemicals, to develop and commercialize the process. Promising to reduce reliance on oil while expanding markets for domestic agriculture (and also significantly reducing costs and 01997

Elsevicr Science

Additives@

Polymrrs

generation of waste) the process makes succinic acid as a first stage, by fermentation of glucose sugar from corn, and then separates and purifies the acid, finally converting it chemically to 1,2-butanediol, tetrahydrofuran, N-methyl pyrrolidone and other chemicals, as bases for a wide assortment of products. The feedstocks produced can be used to make solvents and plastics, for fibres, inks, paints and food additives. Existing markets for these chemicals in the USA are estimated to run to nearly 450 000 tonnes, valued at over $1.3 billion. Researchers at Argonne have applied genetic techniques to mutate a bacterium which normally produces only small amounts of succinic acid to make a new organism which produces greater amounts. An efficient process for purifjring the acid from the mixture of materials found in fermentation booths has also been developed. Contact: Evelyn Brown, oflice of Public 4fi .fairs, Argonne National Laboratory, 9700 South Cass Avenue, Argonne Ii, 60439, [JSA; tel: 4~f-630 252 55iO

TECHNICAL

BRIEFS

Solvents and plasticizers in thermotropic LCPs Thermotropic liquid crystalline polymers (TLCPs) with low temperature transitions (a few degrees above ambient) are the subject of much interest, since they combine the liquid crystallinity of rigid polymers with the mechanical properties of flexible chains, and are applicable to many technologies. Recent research in Canada (reported in Polymer) studied the effect of solvent and of small molecule plasticizers on the rheology and morphology of a main chain TLCP with a low melting transition. The research shows that the relative molecular conformations of polymer and plasticizer

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