Is the search for a poly glue over?
From 3M
Two-part epoxies have evolved over three dis- 
Among the most recent advances in acrylic tech- 
nology are 3M Scotch-Weld Structural Plastic Ad- 
hesives DP-8005 and DP-8010. These readily bond 
polypropylene, TPOs, and other difficult-to-bond 
low surface energy plastics. They provide high 
shear and peel strengths while reducing the 
surface preparation time and cost of traditional adhesives. 
at:
http://www.pressreleasefinder.com/prdoc ... rticle.pdf
Unfortunately it looks like the small quantity tubes from Granger etc require a $40 applicator.See:
http://tinyurl.com/b6yqj
But also checkout  
3M(TM) Scotch-Grip(TM) Plastic Adhesive 4693, 
It has immediate bond strength, long tack range and contact bond properties. It exhibits outstanding bond strength to metals and many plastics, including polypropylene, polyethylene and high-impact polystyrene. Good resistance to water and aging.   
4693H is a thicker version available in tubes at:
https://rshughes.com/products/021200_30088.html
I've ordered a tube and will post results later.[/i]