Engineering360: "How to recycle polymer waste"

Essentially what we were doing 50 years ago in Zambia when every little counted.

What is REALLY needed to properly recycle polymers is to use the ones from bio-organic sources like corn stalks, hemp, lobster shells, seaweed (and etc) and STOP using petro-chemicals. Even when recycled or in the recycling process, petro-chemical polymers produce very environmentally destructive compounds.

Technically correct but economically and thermodynamically negative (need more energy to do than the amount saved)

Comment 2 follows common assumption that plastics in environment are harmful, a popular image that ignores their nontoxicity. The image is fed by fear of miracle-denying science in general and chemistry in particular, and is not going away.

A bio-source is OK if it does the same job (e.g., sugar-based polyethylene), but requires inputs of energy, water and land to grow, harvest and process into plastics, and dispose of ag waste.

Making less of everything (not just plastics) is ecologically useful, but culturally disrupting. Look at the effects of COVID-19 if you need proof.

More research is clearly warranted. In the meantime, while we are stuck with these materials (plastics are cheap to buy but very costly in the long-run [including all the energy spent mitigating their long-term effects]), we ought to work harder to reduce the use of plastics. While we're doling more research on petro-plastic replacement materials we ought to employ non-petro-plastic options, i.e. returning to more paper and waxpaper use. Albeit these "old-school" methods are less ideal and more expensive on the front end, they are less costly on the backend. We get to through mass market use (yes, including regulation - it IS a public health issue), phase out the plastics, or at least greatly (more than 75%?) reduce their use.

Just sayin

Yes, I KNOW some waxpaper uses petro-parafin, AND I submit feasible (tho again, pricier on the front-end but less costly on the eternal back end) biological/renewable replacements for petro-parafin are availble. Even if it takes a while to phase in a petro-parafin replacement, waxpaper has lot less petrochemicals than the plastic wrap or plastic bad it is replacing.

Renewable doesn't mean renewed, just as recyclable (which all plastics are) doesn't mean recycled. And recycling isn't necessarily enviro-positive until we know the energy inputs and what the new end-use is. The weight of wax (petrosourced) is more than the .0005" thickness of polyethylene that is on cartons, paper cups, and many other uses, and the PE doesn't crack or pinhole. It takes energy to make paper, too, and even in renewably-managed forests, it takes people and energy to grow and harvest and process the trees successfully. I suspect that PE does its job with lower environmental impact than anything else eligible.

However, that doesn't matter to the critics of plastics. There are technical counter-arguments, and no commercially important polymer is biologically toxic (the long chains resemble fats, and nylons are like proteins, except less reactive). But this is avoided and resented by the part of most all people that needs belief in impossibles (magic, theater, make-believe). Anything natural is usually predictable, even poisons, but plastics are synthesized by people. FDA or not, its us we distrust.

We also follow popular images, and "plastics = bad" is one of them. Belonging to anti-plasticism" makes us feel better, especially if we don't give up their benefits: wire insulation including power transmission, ag irrigation pipe, surgeon's sutures and medical PPE, light computer housing and mice, fishing line, fuel saved because cars and planes are lighter and homes better insulated, all synthetic textiles (nylon is plastic), nonburning Christmas trees, Velcro and all clear adhesive tape, the boxes that keep COVID vaccine super-cold as needed, other boxes that postal workers can handle and stack (1.55 lb HDPE), contact lenses, microwavable trays for takeout meals, toothbrush handles and bristles ....

But, like I said before, it doesn't matter. We learn absolute unexplained authority as babies, and the need for logic is learned later, as little/as much as necessary. We have a built-in fear of judgment as it might contradict what we want to believe. I don't expect to change this, but would like some of us techies at least to see it.

I don't have the time to go down your defeatist rabbit hole right now. I suspect tho, you are mistaken with your facts in the first paragraph and the next three paragraphs are ad-hominem sophistry.

I'll come back and give you some empirical what-for later.