In message , K
writes
Jeff Layman writes
JennyC wrote:
"shazzbat" wrote in message
...

"Jeff Layman" wrote in message
...
JennyC wrote:
Came across this by accident :

http://www.zerowaste.co.nz/default,163.sm

http://www.sci-scotland.org.uk/greenhouse.html

:~))

Interesting, but I believe that PET is not particularly stable
under UV light. It would probably not be too long before the
greenhouse disintegrated.

I line my GH with plastic bubble wrap, and that lasts several years
before disintegrating. I'd imagine the bottles would last longer,
being thicker.... Jenny

Bubble wrap is polythene. Bottles are Polyethylene Terephthalate.
Completely different things, despite the somewhat similar names.

Polythene = polyethylene. So how different? - can you point me to an
url with the chemical structure of both?

(Not doubting you, just curious).

Polythene (polyethylene) is an addition polymer of ethylene i.e. (C2H4)n

PET (polyethylene terephthalate) is a condensation copolymer of
terephthalic acid and ethylene glycol, i.e. (COO.C6H6.COO.C2H4)n

http://en.wikipedia.org/wiki/Polythene
http://en.wikipedia.org/wiki/Polyethylene_terephthalate
--
Stewart Robert Hinsley