caps and pvc?

From:  rpittman-at-juno-dot-com [SMTP:rpittman-at-juno-dot-com]
Sent:  Tuesday, April 14, 1998 9:32 AM
To:  tesla-at-stic-dot-net
Subject:  Re: caps and pvc?

>Polyethylene is a low loss plastic, PVC is high loss plastic.

Ok being a science teacher I have to ask, What is it that makes something
high loss and other things low loss?  Crystal structure, molecular make
up,  does the chlorine cause the loss?  Cause polyethylene is just a
bunch of c=c and H right, while the poly vinyl chloride is a vinyl
molecule with some chlorine?  I am sure this is over simplified but just
curious.  Thanks for the help.