Michael Tolinski provides an excerpt from the 2015 second edition of his book Additives for Polyolefins, available from Elsevier.
Polyolefins such as polyethylene and polypropylene could be credited with having sustainable characteristics of various kinds, in comparison to those of alternative materials that might be used for similar products. Although associated with waste and littering in the public discourse, their production, use, and end of life do have some positive “green” aspects:
Polyethylene and polypropylene are based on relatively simple molecules, and the energy used in their production is relatively low compared to other polymers.
- Polyolefins, especially when compounded to be durable using additives, offer energy and material savings in use.
- Polyolefin polymers are non-toxic and relatively inert and durable.
- Polyolefins’ durability and thermoplastic nature also mean that they are among the most-recycled plastics.
Taking a broad view of the concept of “sustainability,” we might describe a “sustainable” plastic additive or reinforcement simply as an additive that helps a polyolefin (or any polymer-based material) meet one or more of the above goals more effectively and efficiently. But it's a worthwhile exercise to look for a deeper conceptual framework with which to talk about additives specifically.
One framework to consider is the “Principles of Green Chemistry,” developed in the 1990s by P.T. Anastas and J.C. Warner for their book Green Chemistry: Theory and Practice. Although their twelve principles were formulated mainly for the chemical industry, some of them are helpful when discussing additives and sustainability .
These principles should be read keeping ideas in mind about the additive's production, its use in the plastic product, and its end-of-life influence on the polyolefin plastic. Here are a few principles that can be made relevant to polyolefin additives:
This article appeared in the Jan/Feb issue of Reinforced Plastics.