Raw material of tyre:

1. Rubber (Natural rubber or blend of natural rubber and synthetic rubber)

2. Filler (Carbon black)

3. Plasticisers (Oils)

4. Activators (Zinc oxide and stearic acid)

5. Anti oxidant

6. Curatives (Sulphur)

You can go through the following links: http://www.madehow.com/Volume-1/Tire.html

https://www.youtube.com/watch?v=bflliMKnEUA

And so many literature and videos are also available in internet.

Coming to the 2nd part of your question: Yes rubber can be melted. Simply you can run the rubber sample in DSC, you will get definite onset melting and melting peak temperature for each rubber.

DSC?

Differential Scanning Calorimetry (DSC), it is a analytical technique to measure the thermal property of the sample during phase transition.