Wikimedia
Wikipedia: Rubber
Wikipedia provides detailed information on rubber, a hydrocarbon polymer. Includes information on the composition and uses of rubber.
Other
Rubber Manufacturers Association: Rubber Fa Qs
A quick overview of the developments of vulcanized rubber and synthetic rubber.
NSTATE
People of Connecticut: Charles Goodyear
At this site you can read about Charles Goodyear. This man invented the vulcanization of rubber in 1844.
National Inventors Hall of Fame
National Inventors Hall of Fame: Charles Goodyear
Charles Goodyear made improvements in India-rubber fabrics which eventually lead to the formation of tires. The National Inventors Hall of Fame website contains a short biography about this inventor.
Other
Rubber Stichting: Engineering With Natural Rubber
High level discussion of engineering-related formulas of rubber engineering.