The Collaborative International Dictionary of English v.0.48:

Vulcanize \Vul"can*ize\, v. t. [imp. & p. p. Vulcanized; p.
   pr. & vb. n. Vulcanizing.]
   To change the properties of, as caoutchouc, or India rubber,
   by the process of vulcanization.
   [1913 Webster]

   Vulcanized fiber, paper, paper pulp, or other fiber,
      chemically treated, as with metallic chlorides, so as to
      form a substance resembling ebonite in texture, hardness,
      etc. --Knight.

   Vulcanized rubber, India rubber, vulcanized.
      [1913 Webster]

WordNet (r) 3.0 (2006):

vulcanized
    adj 1: (used of rubber) treated by a chemical or physical
           process to improve its properties (hardness and strength
           and odor and elasticity) [syn: cured, vulcanized,
           vulcanised]