Skip to main content

Plastic Pipes.

Plastic Pipes.

  • Plastic pipes are tubular sections or hollow pipes/cylinders made of plastics.
  • They are usually but not necessarily of circular cross-section.
  • The plastic pipes are used to convey substances that can flow such as liquids and gases (fluids), slurries, powder and small mass of solids.
    Slurries.
  • They are used as hollow pipes.
  • Hollow pipes are stiffer than solid pipes.
  • A common example of plastic pipe is polyvinyl chloride (PVC) pipes made from combination of plastic and vinyl chloride.
    Polyvinyl chloride pipes.
  • PVC pipes are durable, hard to damage and long-lasting.
  • They do not rust, rot or wear overtime.
  • Thus, these pipes are used in water system, underground wiring and sewer lines.
  • The monomer used in production of PVC is vinyl chloride.
    Polyvinyl chloride formation.
  • The polyvinyl chloride is produce by heating a water-emulsion of vinyl chloride in the presence of benzoyl peroxide or hydrogen peroxide in an autoclave under pressure. Next
    Autoclave.

Comments

Popular posts from this blog

Determination of molecular weight by osmotic pressure method

Determination of molecular weight by osmotic pressure method. Osmotic pressure method is also called membrane osmometry. This method is widely used to determine the number average molecular weight of polymers. This method is based on the phenomenon of osmosis. If a pure solvent is separated from a solution through a semipermeable membrane, due to concentration (chemical potential) difference between the solvent and solution, the solvent will flow into the solution through semipermeable membrane. The pressure applied on the solution to completely stop the flow of solvent into it through semipermeable membrane is called osmotic pressure. The theory of osmotic pressure also applies to a solution of polymers. Ordinary solution obeys Van't Hoff equation i.e π=cRT/M Where π is osmotic pressure, c  is concentration in mass per unit volume, R is gas constant, T is temperature and M is molar mass. The polymer solution are non ideal. Taking into account their deviation and us...

Polylactic acid/PLA.

Polylactic acid/PLA. Polylactic acid is a biodegradable thermoplastic polymer . Polylactic acid is obtained from lactic acid monomer. Polylactic acid. Polylactic acid is stable to UV radiation. Polylactic acid has good resistance to moisture. Polylactic acid has good elasticity. Polylactic acid is an aliphatic polyester . It can be used as a food packaging polymer. Polylactic acid is suitable for textile fibre applications such as shirts, carpets, sportswear etc. Polylactic acid is used in implants and medical devices (screws, sutures etc). Polylactic acid is suitable for use in floor mats. Uses of Polylactic acid. Questions on Polylactic acid/PLA; Q1) What is Polylactic acid? Ans) Polylactic acid is a biodegradable thermoplastic polymer. Q2) What is the monomer of Polylactic acid? Ans) Polylactic acid is obtained from lactic acid monomer. Q3) Write some properties of Polylactic acid? Ans) Some properties of Polylactic acid are given below; ...

Polytetrafluoroethylene (PTFE) or teflon

Polytetrafluoroethylene (PTFE) Polytetrafluoroethylene (trade name- Teflon), was accidentally discovered by Roy Plunkett (a Dupont chemist). This is a polymer which has repeating chains of -(-CF₂-CF₂-)- in it. It is an addition polymer of tetrafluoroethylene (CF₂= CF₂). It is obtained by heating tetrafloroethylene in a presence of catalyst at high pressure. Polytetrafluoroethylene. Polytetrafluoroethylene is produced by the free radical mechanism. It is resistant to many chemicals. It is weather and UV resistant. It is non sticky. It appears to be quite slippery. It has outstanding performance at extreme temperatures. It is used as a non-stick coating for cooking pans and utensils. Teflon is also used in curling irons and straighteners. Teflon is also coated on the iron to quicken the heating up process. Teflon is also used as artificial limb and body parts. Teflon tape or plumber's tape is a polytetrafluoroethylene film tape commonly used in plumbing. Teflon...