Sciencemadness Discussion Board

PET vs. HDPE bottles

mycotheologist - 16-4-2012 at 07:30

I have the urge to look for the recycling code on every plastic container I come across and I've noticed that clear, transparent plastic bottles:

are always made of PET whereas HDPE bottles/containers are never fully transparent but instead look like this:

would I be right in assuming its impossible or impractical to make clear, translucent HDPE containers, whereas it can be done with PET? As a chemistry hobbyist, I'm a big fan of HDPE due to its chemical resistance and so far, I've found no uses for PET. I read that PET is highly impermeable to CO2 which makes it ideal for storing carbonated drinks but does it have any advantages over HDPE for the home chemist?

Hexavalent - 16-4-2012 at 09:07

Not relevant to the topic, but Nicodem I think this thread was more suited where it was . . .just MO:)

bbartlog - 16-4-2012 at 09:21

For storage, I don't believe so. But as feedstock, sure: you can depolymerize the PET. There's a decent post about it in Prepublication.

Morgan - 16-4-2012 at 17:32

One thing I don't like about HDPE is that it yellows over time moreso if exposed to sunlight. LDPE doesn't do that. I have some thick-walled 4 liter bottles I bought, 6 of each. They are shaped like the ones here with the blue liquid.
http://www.usplastic.com/catalog/item.aspx?itemid=23612