A polymer is a high-molecular-weight organic compound, natural or man-made,
consisting of many repeating simpler chemical units or molecules called
Examples of natural polymers are proteins (polymer of amino acids) and
cellulose (polymer of sugar molecules).
An example of synthetic polymer is PVC (a polymer of vinyl chloride).
Polymer chain structure of one of the simplest and most common
Source: University of Florida
Cellulose - PVC - Protein