A review of small molecule diffusion in polyolefins

The transport of small molecules in polyolefins is a subject of both technical and commercial importance. It is technically important because the factors, such as morphology and molecular interactions, that control diffusion are not well determined. Also, the existing theory of diffusion, based on macroscopic parameters,7 It is commercially important because the use of polyolefins in applications such as wire coatings, barrier layers and structures is extremely widespread. Failure of such applications can impact the lifetime of large amounts of capital investment. Examples such as wire and cable, landfill liners and automotive components all have expected lifetimes. Previous research indicates that loss of stabilizers may be the major factor in failures and that previous estimates of the loss mechanisms have been inaccurate due to a lack of basic knowledge about the transport properties of polyolefins. This review attempts to cover the previous work on transport in polyolefins and to correlate the results where possible.