Types of Plastics and Classification of Plastics

Types of Plastics

Polyethylene (PE): Has a wide range of applications and is very cheap.
Polypropylene (PP): One of the most widely used plastics. Used in the automotive supply industry, garden furniture, etc.
Polystyrene (PS): Used in packaging, electronics, plastic parts of white goods, etc.
Polyethylene terephthalate (PETE): The name “PET bottle” comes from this material.
Polyamide (PA) (Nylon): Used in fiber, toothbrush bristles, fishing line, etc.
Polyester: Widely used in textiles.
Polyvinyl chloride (PVC): Used in the manufacturing of pipes, profiles, etc.
Polycarbonate (PC): Used in the manufacturing of CDs, eyeglasses, etc.
Acrylonitrile butadiene styrene (ABS): Widely used in the plastic components of electronic devices.
Polyvinylidene chloride (PVDC) (Saran): Used in food packaging.
Polytetrafluoroethylene (PTFE) (Teflon material): Used for heat resistance, cooking pans, etc.
Polyurethane: Used as insulation foam.
Bakelite
Polylactic acid

Types of Plastic by Chemical Composition

1. Phenolics (Phenol, Cresol – Formaldehyde)
2. Amine plastics (carbamide melamine, aniline, formaldehyde)
3. Amide plastics, sulfamide plastics
4. Alkyd plastics, polyester
5. Ethylene plastics, polyethylene and its derivatives
6. Vinyl plastics, polyvinyl chloride, polystyrene
7. Vinylidene plastics, acrylic plastics
8. Cellulosic compounds, cellulose and its derivatives
9. Silicone plastics
10. Hard rubber plastics, rubber derivatives

Types of Plastic by Chemical Reaction

1. Polycondensation: Condensation,

a chemical reaction in which water or another substance is separated out during a reaction between two separate molecules. If this is followed by a polymerization reaction as described in item 2, large molecular assemblies (complexes) called polycondensates form. Phenolics, amine plastics, and polyester fall into this group.

Polymerization

Polymerization is the process by which many small molecules gather together into a single molecular chain. In this way, new polymer materials with new properties are produced without releasing any substance other than the plastic itself. Polyethylene, polyethylene derivatives, vinylidene plastics, acrylic plastics, etc. fall into this group. Polymerization can be shown as the opposite, reversible process of condensation.

Types of Plastic by Molecular Structure

What distinguishes plastics from other materials is that their mechanical properties depend more on their molecular structure than on their chemical composition; as a rule, then, the structure formed by adjacent molecules has a great deal to do with mechanical properties. Because of this, despite fundamental differences in chemical composition, plastics with an identical molecular structure are used in the same applications. Plastics can be divided according to their molecular structure as follows:

1. Polymers with a linear (chain-shaped) molecular structure:

Individual molecules are not bonded to one another. This is the typical structure of thermoplastics.

2. Polymers with a three-dimensional network molecular structure

Here, the molecular groups that make up the structure are three-dimensional due to cross-links between the molecular chains in every direction. This type of structure defines the plastics that can harden (thermosets).

3. Elastomers (Vulcanized Rubbers)

Here we find molecular chains joined by bridges formed from some vulcanizing substance (for example, sulfur). In vulcanized rubber, this is the typical appearance of thread-like molecules linked by sulfur bridges. Vulcanized rubbers are flexible.

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