Re: I wish to form short lengths of braided polypropylene rope into rings.

Bob,
    There is an adhesive called NBond that should do the work. One of the 
suppliers is 

Nbond Adhesives International. Their address is

6607 Condor Run
Littleton, Colorado
USA 80125 
+1.303.948.5434 Phone
+1.303.972.0018 Fax

This adhesive is a two-part thermoset polymeric adhesive and is especially 
suited to permanently bond materials like polypropylene, polyethylene, 
wood, paper etc. It cures at room temperature. For further information 
look at 
 http://www.nbond.com/techdata.html

They have some details on the adhesive. Hope this helps.