Posted tagged ‘low density polyethylene’

PLASTIC

August 23, 2011

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

01-Plastics-food-containers-durable plastic products-plastic boxes

Characteristics of Plastics

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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”

01-Reaction to produce plastics-plastic formation-industrial plastic manufacturing-plastic production methods3. 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