Utilizing minerals and materials with negative properties

Minerals & Metallurgical Processing , 2010, Vol. 27, No. 1, pp. 1-7

Douglas, G.W.; Schnabel, S.; Kjerengtroen, L.; Kellar, J.J.

The need for dimensionally stable filled polymer composites has spurred the quest for materials that possess a negative coefficient of thermal expansion (CTE). Finding minerals and materials with a negative CTE large enough to counteract the substantial CTE found in polymers proves challenging. Much research has been performed over the last decade to uncover various materials that possess this unusual behavior. A list of materials that have demonstrated negative properties are discussed, as well as the experimental use of one such material (ZrW₂O₈), in a polymer matrix composite. Other negative properties, such as negative Poisson’s ratio and negative stiffness, are also examined.