Utility of Plastics
Plastics are excellent materials with unique and very useful properties. You can produce just about anything you can imagine using plastics.
Solid, lightweight plastics help us live happier lives while still leading to sustainability in a variety of ways, all of which are based on plastics’ ability to help us do more for less.
Plastics contribute to environmental protection by eliminating waste, decreasing greenhouse gas emissions, and conserving electricity at home, work, and on the road. Plastic packaging allows consumers to transport more goods with fewer packaging content, extending the shelf life of fresh foods and drinks and reducing both food and packaging waste.
Characteristics of Plastics
History Of Plastics:
1. Before Plastics—Age of the Natural Resins
- Rubber—Tough elastic substance (light cream or dark amber
colored) from the milky juice (sap) of rubber tree
- Ebonite—Hard black rubber; natural rubber + sulfur
- Gutta-Percha—Dark brown substance like natural rubber
- Shellac—dark-brown material from lac insects
2. Bakelite—The First True Synthetic Plastics
- Leo Hendrik Baekeland invented Bakelite from coal
- Bakelite helped make 20th century “The Age of Electricity”
|Year||Type of plastics||Note|
|1872||Celluloid (Hyatt, USA)||Semi-synthetic|
|1910||Phenolic resin, “Bakelite” (Baekeland, USA)||From coal|
|1931||Polymethyl methacrylate (PMMA) (Rohm and Haas, Ger-many)||From coal|
|1935||Polyvinyl chloride (PVC) (IG Farben, Germany)||From coal|
|1935||Polystyrene (IG Farben, Germany)||From oil|
|1938||Nylon 6 (IG Farben, Germany)|
|1939||Nylon 66 (DuPont, USA)||From coal|
|1939||High-pressure low-density polyethylene (LDPE) (ICI, Eng-land)|
|1953||Polyethylene terephthalate (PET) (DuPont, USA)|
|1953||Low-pressure high-density polyethylene (HDPE) (Montecatini, Italy)||Ziegler catalyst|
|1955||Medium-pressure high-density polyethylene (HDPE) (Phillips, USA)||Phillips catalyst|
|1957||Low-pressure high-density polyethylene (HDPE) (Hoechst, Germany)||Ziegler catalyst|
|1959||Polypropylene (Montecatini, Italy)|
|1977||Linear low-density polyethylene (LLDPE) (UCC, USA)|
|1991||Metallocene very-low-density polyethylene (VLDPE) (Exxon, USA)||Metallocene cata-lyst|
4. Concept of High Molecular Weight Compounds & Polymers
- Herman Staudinger, German chemist, proposed a new theory that several thousands of reactive units bonded together in chains and form giant molecules to make up cellulose and rubber
- In 1920, Staudinger proposed calling such materials: high molecular weight compounds, macromolecules, or polymers.
5. Nylon—The First Tailor-Made Plastics
- 1931 – Fiber 66 was produced, later called Nylon 66 in 1938
6. What Really Is Plastic?
A plastic is a synthetic or man-made material that resembles natural resins used in trees and other plants in several respects. Polymers are described as “any of various complex organic compounds formed by polymerization, capable of being shaped, extruded, cast into various shapes and films, or drawn into filaments and used as textile fibres” according to Webster’s Dictionary.