PLASTIC-2

What are Plastics?

Plastics are a material that is made up mainly of macromolecules, that can be made fluid by the action of heating and pressurizing, and that can be processed into end products with any useful shape you want to make.

Classification of Plastics

Plastics can be classified into:

1. Thermoplastics and Thermo sets
2. Amorphous Thermoplastics and Crystalline Thermoplastics
3. Commodity Plastics and Engineering Plastics

Thermoplastics Vs Thermo sets

Thermoplastics Elastomer

• TPE – thermoplastic elastomer
• Resemble rubber at room temperature
• Can be melt-processed like other thermoplastics
• Become elastic like rubber when cooled

Amorphous Thermoplastics Vs. Crystalline Thermoplastics

Thermo sets Classifications

Commodity Plastics Vs Engineering Plastics

PLASTIC

Plastics are excellent materials with unique and very useful properties. You can produce just about anything you can imagine using plastics.

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”

3. Industrialization of Major Plastics

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