I know little of chemistry, but I would assume this wouldn't work where longevity was needed, especially in moist environments, since there are plenty of bacteria that will happily break down the types of bonds in carbohydrates.
Protective coating could be a good approach for some things, typically of intermediate lifespan.
Protective coatings are becoming used more and more extensively in many fields, and they can produce astonishing results.
That said, with applications for sugar-based structures, the slightest flaw, scratch, cut, or perforation becomes a barn door through which bacteria can drive their metaphorical horses and carriage.
But for temporary applications such as packaging, a sugar-based material with a thin coating (maybe plastic, maybe another material) to preserve it for a short life, but allow it to biodegrade or compost could be excellent. For example, I find it particularly ironic that when the garden is out of season, I go to the grocery store only to find "organic triple washed" greens packaged in permanent plastic clamshells that will last for years. Sure, it does the job of getting the greens to us, but then it is making the problem worse.
Probably unrelated, but here's a neat video about the problems with resin coated rebar: https://youtu.be/xVDy84rR5Z8
TLDW: in practice, it's worse than leaving it bare! Probably unrelated because it's rebar degradation is ionic, so it can concentrate, where decomposition from microorganisms is surely related to the actual surface area.
Bacteria famously can’t break down cellulose—wet or dry—, a structure made of glucose monomers. It took fungus hundreds of millions of years of evolution to develop the ability to break down cellulose.
See firmicutes [1] and bacteroidetes: cellulomonas, thermobifida, clostridium. Bacteria also experienced those hundreds of millions of years. In fact, there's some cellulose melting bacteria in your gut right now! ;)
But, you are right that it's not just bacteria [2].
That isn't an issue here. Structural polysaccharides, such as the cellulose used in this case, can be engineered to be extremely durable while remaining biodegradable. In cases where extreme longetivity is required (i.e. decades, centuries, universal heat death, etc.), biodegradable materials were never an option to begin with.
I'm not sure I understand. You seem to be restating what I said. These are not appropriate for longevity, and will biodegrade. Could you help me understand what I'm missing here?
What if that’s exactly the point — it’s a material not designed for longevity? I mean I hate disposal plastic as much as anyone who’s seen a turtle with a straw stuck up its nose, but paper straws really don’t work more than 3 min.
To keep conveniences like my iced caramel frappalattechino we need a fast biodegradable, but like 3 hours degradable not 3 min degradable.
No idea if this is that, but “artificial shapes made of sugars like cellulose but not quite cellulose” sounds like you might be able to design something good that isn’t a forever chemical.
Remember SunChips? They made a “this multi-layer plastic snack bag can actually biodegrade AND keep our snack grease from leaking out on the shelf” chip bag. But they killed it because every crinkle sounded like a gun so people hated it. We still haven’t figured out those kinds of materials that work well.
3 hour biodegradable is too fast. The material has to go somewhere. If it breaks up before it can be collected it's going to make a mess and cause buildups of whatever can feed off the carbs you're spreading everywhere.
Only around 36% of plastic is used for packaging. My comment was a direct response to the grandparent comment. If “for packaging” were included, I would have agreed. Replacing only plastic used for packaging will leave us dependent on oil.
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[ 144 ms ] story [ 1034 ms ] threadProtective coatings are becoming used more and more extensively in many fields, and they can produce astonishing results.
That said, with applications for sugar-based structures, the slightest flaw, scratch, cut, or perforation becomes a barn door through which bacteria can drive their metaphorical horses and carriage.
But for temporary applications such as packaging, a sugar-based material with a thin coating (maybe plastic, maybe another material) to preserve it for a short life, but allow it to biodegrade or compost could be excellent. For example, I find it particularly ironic that when the garden is out of season, I go to the grocery store only to find "organic triple washed" greens packaged in permanent plastic clamshells that will last for years. Sure, it does the job of getting the greens to us, but then it is making the problem worse.
What I was thinking of is similar to wax coated paper cups.
See firmicutes [1] and bacteroidetes: cellulomonas, thermobifida, clostridium. Bacteria also experienced those hundreds of millions of years. In fact, there's some cellulose melting bacteria in your gut right now! ;)
But, you are right that it's not just bacteria [2].
[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4143619
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9277587
To keep conveniences like my iced caramel frappalattechino we need a fast biodegradable, but like 3 hours degradable not 3 min degradable.
No idea if this is that, but “artificial shapes made of sugars like cellulose but not quite cellulose” sounds like you might be able to design something good that isn’t a forever chemical.
Remember SunChips? They made a “this multi-layer plastic snack bag can actually biodegrade AND keep our snack grease from leaking out on the shelf” chip bag. But they killed it because every crinkle sounded like a gun so people hated it. We still haven’t figured out those kinds of materials that work well.