PLASTIC

1 – INTRODUCTION

  Plastics had already been known in the American labs by 1860. The first plastic used was celluloid (cellulose nitrate), industrialized in 1864, solving the lack of ivory in the USA in 1870, despite, the celluloid had a bad start for the plastics.
  Although it replaced some materials and even solved some manufacturing problems, it had a bad start, because, created a discredit in the usage of this kind of material, because the celluloid didn’t have stability, decomposing itself easily when it was exposed to light or heat, besides being highly inflammable.
  The first chemist to develop deeper researches about the polymerization and condensation (process employed during the plastic fabrication), was a Belgian Leo Hendrik Baekelend (1863-1944), making viable a method of reactions of controlled polymerization, through this condensation process, Baekelend developed the first plastic resin, being industrialized in 1909 and having wide application by that time, being used until today. Such resin “Baquelite” received this name because of his inventor.

2 – THE DISCOVERY OF DIFFERENT PLASTICS, FOR DIFFERENT USAGES

  The success in the fabrication and usage in wide scale of Baquelite, encouraged other researchers, starting new systematic investigations about plastics, resulting in a very important number of discoveries.
  The beginning of the industrialization of the first plastics took place in the following years:

- Celluloid – 1864
- Baquelite – 1909
- Silicone – 1930
- Acrylic (PMMA) – 1932
- Polystyrene (PS) – 1933
- Polyamide (PA) – 1935
- Polyethylene (PE) – 1939
- Vinyla-Polycloret (PVC) – 1940
- Acrylonitryle-Butadyene-Styrene (ABS) – 1946
- Teflon (PTFE) – 1948
- Polycarbonate (PC) – 1958
- Polypropylene (PP) – 1959
- Polyacetal (POM) – 1960

3 – BY THE WAY, WHAT IS THE MEANING OF PLASTIC?

  Plastic is every material which has the property of maintaining specific shapes by the action of an outside sturdiness.
  Specifically about the plastic resins, the outside sturdiness means temperature and pressure, influenced by the velocity and the translocation courses of the merged body, besides the pre-specific functions to any kind of plastic.

4 – WHAT IS THE SOURCE OF PLASTIC?

    During millions and millions of years, organic materials (plants, animals, trees, etc), were buried by natural changes over the planet. As the time went by, such materials were slowly decomposed originating petroleum.
  Based of this fact, the petroleum is the source of the fabrication of several  kinds of plastic materials in the market today.

5 – OBTAINMENT

   After its extraction, the petroleum is conducted to a distillation tower where it will be processed.
  At this time, the distillation tower through pre-defined temperatures, separates the chemical substances which the petroleum consists of, according to its volatility (ability to evaporate, when it is subject to an outside specific force, which in this case is the heat).
  During the distillation process, primarily gases which have a unique chemical element are released. After that the monomers are released, which are the hydrocarbons (chemical structure based on carbon and hydrogen).
  After the obtainment of the monomers, the distillation of the petroleum continues, obtaining other products in this sequence: blue gasoline, kerosene, regular gasoline, diesel e bitumen.
  The monomers  may be obtained either in the gas form or in fluid form, and since it is a hydrocarbon, it’s considered a simple chemical compound. Some monomers are: ethylene, propylene, styrene, amide, carbonate, among others.
  The monomer is guided to the interior of a reactor, where through specific temperatures and pressures, will be subject to a polymerization (process which permits the multiplication of monomers millions times in a row, achieving macromolecules).
  It is important to explain that who starts the polymerization reaction is a catalyst placed in the interior of the reactor along with a monomer, being necessary specific temperatures, pressures, and catalyst to have a polymerization reaction and achieve the desired kind of plastic resin.

6 – FROM THE PETROLEUM TO THE FINAL PRODUCT

   This is the summarization of the process:

• Petroleum extracted,
• Monomer acquired from the distillation tower,
• Polymer (plastic resin), acquired from the polymerization process,
• Transformation process (injection, blast, extrusion), from the desired product.

7 – FINAL CONSIDERATIONS

  The manufacturer of plastic resins developed and perfected a huge number of materials, with extremely diversified characteristics and properties, aiming to a achieve a wide area of manufactures. With a growing tendency to replace other materials (iron, steel, wood, rubber, glass, etc) to plastic, and with more simplified production systems, there is a tendency on this segment leading to a promising future, enabling all the plastic organizations to achieve successfully their objectives.
  A classical example, is the manufacture of automobiles; if we compare the vehicle manufactured in the 30’s and another after the turn of the century, we are able to see the number of items which were replaced by plastic items, aiming to develop new technologies, quality and cost.
  To assure even more this tendency, plastics from different sources besides petroleum have already been developed, aiming a 100% biodegradable plastic, keeping its properties, technical characteristics, transformation processes and competitive cost.

8 - BIBLIOGRAPHICAL REFERENCES

BILLMEYER, Fred W - TEXTBOOK OF POLYMER SCIENCE - PUBLISHING HOUSE JOHN WILEY, 2 EDITION, 1970.

STREPIKHEVEV, A; OEREVITSKAYA, V; SLONINDK, G - A FIRST COURSE IN POLYMER CHEMISTRY - PUBLISHING HOUSE MIR - 1 EDITION, 1992.

TANGER, A - PHYSICAL CHEMISTRY OF POLYMERS - PUBLISHING HOUSE MIR - 2 EDITION, 1972.

ALBUQUERQUE, JORGE A. C.  - O PLÁSTICO NA PRÁTICA - PUBLISHING HOUSE SAGRA LUZZATTO, 2 EDITION, 1999.

SORS, LASZIO; BARDOCZ, LARSZIO; RADNOTI, ISTVAN - PLÁSTICOS, MOLDES E MATRIZES - PUBLISHING HOUSE HEMUS, 1 EDITION, 1995.

Brochures, technical catalogs and student´s researches from the Plastic technical course by "SENAI - MARIO AMATO", NÚCLEO DE TECNOLOGIA DE PLÁSTICO "FREDERICO JACOB", from SÃO BERNARDO DO CAMPO/SP - BRAZIL.