**3.1 On the basis of source**


*Natural polymers*: Natural polymers or herbal polymers obtained from nature mean they are obtained from plants and animals. If they are obtained from plant then they are known as "herbal polymers" (**Table 1**).

Example: starch, protein, cellulose.

*Semisynthetic polymer*: These polymers are prepared by chemical process in which natural polymers are used as raw material. Example: silicones, cellulose derivatives.

*Synthetic polymers*: These are pure synthetic material and are prepared by chemical process called polymerization.

Example: polyethylene, synthetic rubbers, nylon, etc.

#### *Natural Polymers as Potential Antiaging Constituents DOI: http://dx.doi.org/10.5772/intechopen.80808*


#### **Table 1.**

*Natural polymers along with their source and properties.* 

## **3.2 On the basis of structure**


*Linear polymers*: In this, monomers are arranged in a straight-line chain. Example: PVC.

*Branched polymers*: In this, there is also a long straight chain, but small monomer chains are attached to this large straight chain.

Example: low density polymers.

 *Cross-linked polymers*: These types of polymers look like a network in which polymeric chains are cross linked with each other [2–6].
