Polymers and Plastics

Introduction to Polymers

Polymers are large molecules made up of long chains or networks of smaller molecules called monomers. Polymers can be natural or man-made i.e., synthetic. Natural polymers include hair, silk, proteins, rubber, cellulose, and DNA among others. Synthetic polymers include polyethylene, polypropylene and polyester among others.

Introduction to Plastics

Plastics are made up of synthetic or semi-synthetic polymers. Plastics to be molded, extruded or pressed into solid objects of various shapes by applying heat and pressure. Special properties of plastics such as low density, plasticity, low electrical conductivity, transparency, and toughness allows this material to be converted into a great variety of products. Polyethylene terephthalate (PET), polyethylene (polythene), polyvinyl chloride (PVC), polystyrene, and polymethyl methacrylate are some examples of plastics used in the production of goods used in daily life. Important engineering plastics are polytetrafluoroethylene (Teflon), polyacetal, polycarbonate, polyamide (trade name nylon), polyphenylene sulfide, polyetheretherketone and epoxy.

Difference Between Plastics and Polymers

The major distinction between polymer and plastics is that polymers are made of connected chains of individual particles or monomers and can be produced synthetically or biologically. Plastics are synthetic or semi-synthetic materials made up of lengthy polymer chains made of small, homogeneous molecules called monomers. So, essentially all plastics are polymers (but the reverse is not true).

Plastics and Polymers Testing

At every stage of the production process, material identification and characterization are crucial. The physical, mechanical, and chemical characteristics of a wide range of materials and products composed of plastic and its polymeric derivatives are specified, tested, and evaluated using plastics standards. These plastic standards such as ASTM standards enable plastic producers and end users to inspect and assess the quality and acceptance of their material or product in order to ensure safe use.