Is the plastic coating on the vinyl itself peeling? Is the awning Carefree or Dometic?
If is on the vinyl itself, you can use a product called VLP (Vinyl Liquid Patch) to touch it up. Duct tape might gum up the works when rolled in. VLP, once dry, is a really good fix.
22 Year Air Force Civil Engineer, Retired.. Generator Tech at Grand Forks AFB, Part time RV Tech and Parts Manager at a Jayco Exclusive RV Dealership