Plastic Materials & Essential Separation Techniques

Plastic Materials: Organic Polymers & Classification

Plastic materials are organic polymers. According to their physical properties or their use, polymers can be classified into:

• Plastics: Polymerization Reactions & Types

  Plastics are produced by polymerization reactions. Some common plastics produced by addition polymerization include polyethylene, polypropylene, polyvinyl acetate, polystyrene, and acrylics.

  • Polyethylene: Used in the manufacture of bags, plastic containers, bottles, and toys.
  • Polystyrene: Used for the elaboration of foam for packaging, thermal insulation, and toys.
  • Condensation Polymerization: A process that forms the polymer and water as another product.

• Resins: Versatile Polymers & Applications

  These are polymers such as polyvinyl chloride (PVC) and polymethylmethacrylate. PVC is used in gutters, floors, and toys. Polymethylmethacrylate, also known as Plexiglas, is used in contact lenses and optical window film.

• Rubber: Elastic Polymers & Industrial Uses

  Elastic polymers such as natural rubber and synthetic rubber. Natural rubber, when vulcanized, is used in the manufacture of tires. Synthetic rubber (e.g., polyurethane) is used in the soles of sneakers and sporting goods.

• Fibers: Strong Polymer Yarns & Types

  Polymers can form resistant yarns. Examples include:

  • Natural Fibers: Silk, wool, cotton.
  • Synthetic Fibers: Polyester, rayon, polyamide, nylon.

• Technopolymers: Advanced Plastics & Properties

  A type of plastic material with enhanced physical and mechanical characteristics, including polycarbonate, acetal resins, polysulfone, and polymethylpentene.

Material Separation Techniques

• Filtering: Separating Solids from Liquids

  Separation of a solid component from a liquid in a heterogeneous mixture. Filter paper is used, where the solid is retained, and the filtrate passes through, free of solid particles.

• Decanting: Settling Solids & Immiscible Liquids

  Separating a solid from a liquid in a heterogeneous mixture by allowing the mixture to stand. It is also used to separate two or more liquids of different densities.

• Screening: Separating Solids by Particle Size

  Separates two solids whose particles are of various sizes by passing the mixture through a special sieve. The larger particles will be retained on the sieve.

• Magnetization: Separating Magnetic Solids

  Used when one component of a solid mixture possesses magnetic properties. A magnet is used to attract and retain the magnetic particles, separating them from the non-magnetic components.

• Simple Distillation: Purifying Liquids & Solids

  Separates a solid component from a liquid, or two liquids with different boiling points, in a homogeneous mixture. To do this, the mixture is heated until the liquid evaporates and the solid remains in the container. In the case of mixing two liquids, the liquid with the lower boiling point will evaporate first. Simple distillation equipment allows the evaporated liquid to cool and condense before being received in liquid form in a beaker.