Boiling point - Polymers never boil. The number 80 is arbitrary. I've seen no reference that set a standard number for this. In the example below, chains of sufficient length to give a minimum performance for some mechanical property in the yellow-green zone are called polymers. Solubility Most polymers are insoluble in water.
Some polymers can be soluble in strong organic solvents.
Polymer nonsolubility is an advantage for a finished product. However, it may present a tiresome problem for the engineer who is trying to manufacture a product. Tensile strength - Tensile strength measures how difficult it is to break a substance when stress is applied to pull it apart. Tensile strength generally increases with molecular weight. An Instron grips a sample and pulls it apart.