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I always found it interesting that the plastics we think of - nylon, polyethylene, Teflon, etc. - are man-made and that there are actually naturally occurring p
by eggy 3y ago
I always found it interesting that the plastics we think of - nylon, polyethylene, Teflon, etc. - are man-made and that there are actually naturally occurring plastics, or polymers such as pectin, cellulose, silk, and wool.
The shapes, opacity, and colors of man-made objects made of plastic were what I always thought of, not pectin or wool, or our own protein and DNA in our bodies. The synthetic vs. natural dichotomy or phrasing made that seem non-intuitive.
I am not saying microplastics or polymers are not harmful. It just makes me think of it as less of an alien molecule or structure because it's man-made when I became aware of what polymer, or plastic, actually meant. I am also hoping that maybe there is less of concern to worry, but not that they are not doing harm.
I am old enough to remember milk delivered in glass bottles, paper bags, and wax paper liquid containers before plastic took over. Even soda was in glass bottles. All of my children were breast fed and raised with glassware and steel utensils. I buy the wax paper containers of milk and juices, so who knows what's in those?
Even the article mentions they don't know accumulation levels yet, and what does microplastics and nanoparticles in the 4.2 million to 1.2 billion particles respectively plastic shed per square centimeter mean in terms of molarity in a liter of blood and does it accumulate and keep building up? A lot of unanswered questions and another thing to add to the dread pile.
- im3w1l 3y agoPectin, ceullose, silk and wool. All of those will be degraded when left out. Man-made plastics will not. That's why we love them and that's why we fear them.
- adrian_b 3y agoStrictly speaking, plastics are only the polymers that can be used to make things by plastic deformation. There are two kind of plastics, thermoplastics, which are heated until they become soft and then molded in the desired form. Besides the thermoplastic polymers, this kind of behavior is also exhibited by metals and glasses. The second kind of plastics are the thermoset polymers, which are first made in a soft form, then molded in the desired form, and then they are hardened by various methods, e.g. by baking. Besides the thermoset polymers, this kind of behavior is also exhibited by ceramics and cements. So while the plastics are polymers, many polymers are not plastics. Most polymers that are made by the living beings are not plastics. Those that have a linear structure suitable for thermoplastics are degraded by heat, so they cannot be heated enough to become soft. Those that have a cross-linked structure like thermosets are already hardened and they cannot be reverted to a soft state. So substances like wool, silk, leather, wood are not plastics, even if they are polymers. One of the few natural plastics is beeswax, which has been used for many millennia as a thermoplastic material. Other examples are various kinds of pitch or resin extracted from plants, or bitumen.
- eggy 3y agoThanks for the clear explanation on polymers and plastics. Very interesting. Bitumen is pretty nasty!