C5h6 reacts with itself to form c10h12 according to the following process

When carbon compounds react with themselves to form a larger molecule the process is called polymerization. Specifically addition polymerization. sometimes molecules containing containing carbon to carbon double bonds can join together to form longer chains. The double bond is broken and the electrons in it join to neighboring molecules. 

Muscle fiber i think that i right

Polyethylene is a strong synthetic polymer that can be used to make toys and bottles. polyethylene is a plastic material called thermoplastic. one very useful property of thermoplastic is that when it is heated it turns into liquid, which can be molded into desired shape and size. also the material do not dissolve at room temperature.