Elastomeres are "defined" as:
"linear-chain polymers with widely spaced cross-links attaching each molecule to its neighbours"
Now I found sentences (talking about glass transition):
"This means that at room temperature the secondary bonds are melted and the molecules can slide relative to each other with ease. Were it not for the cross-links, the material would be a viscous liquid, but the cross-links give it a degree of mechanical stability."
So, what exactly are these bonds that melt? and which ones do not? An example would be nice. Chemistry is not my strongest field so be rigorous.
The quotations are from cellular solids by gibson and ashby.