   Thermosets which are formed by ha heat                   important commercial source of natural
    process but are then set (like concrete) and             rubber (sometimes called Pará rubber) is
    cannot change shape by reheating. e.g.                   the tree Hevea brasiliensis. The only other
    melamine (kitchen worktops), Bakelite                    plant under cultivation as a commercial
    (black saucepan handles), polyester and                  rubber source is guayule.
    epoxy resins.                                           The main use of natural rubber is in
Some Common             Polymers      and    their
monomers                                                Explosives
  Name(s)                     Monomer                   It is a reactive substance that contains a great
  Polyethylene                ethylene                  amount of potential energy that can produce an
  Polyethylene                ethylene
                                                        explosion if released suddenly, usually
  Polypropylene               propylene
  Poly(vinyl chloride)        vinyl chloride            accompanied by the production of light, heat,
  Poly(vinylidene chloride)   vinylidene                sound, and pressure. An explosive charge is a
                              chloride                  measured quantity of explosive material. e.g.
  Polystyrene                 styrene                   TNT- trinitrotoluene, RDX- cyclonite, PETN-
  Polyacrylonitrile           acrylonitrile
  Polytetrafluoroethylene     tetrafluoroethylene       pentaerythritol tetranitrate, nitrocellulose,
  Poly(methyl methacrylate)   methyl                    nitroglycerin, etc.
  Poly(vinyl acetate)         vinyl acetate             Chemical explosive is a compound or mixture
  Polychloroprene             chloroprene               that releases chemical energy violently and
                                                        rapidly, creating heat and a shock wave
                                                        generated by a release of gases.
                                                        Dynamite is an explosive made by soaking an
   It is a natural or synthetic substance that is
                                                        inert (inactive or stable), absorbent substance
    significantly longer than it is wide.
                                                        with a mixture of (1) nitroglycerin or
   The strongest engineering materials often
                                                        ammonium nitrate, (2) a combustible
    incorporate fibers, for example carbon              substance (a substance with the ability to
    fiber and ultra-high-molecular-weight               burn), such as wood pulp, and (3) an antacid.
   Synthetic fibers can often be produced              Gunpowder is an explosive mixture of
    very cheaply and in large amounts                   charcoal, potassium nitrate, and sulfur often
    compared to natural fibers, but for                 used to propel bullets from guns and shells
    clothing natural fibers can give some               from cannons.
    benefits, such as comfort, over their
    synthetic counterparts.                             Nitroglycerine is an explosive liquid used to
                                                        make dynamite. Also used as a medicine to
Natural Rubber                                          dilate blood vessels.
   It is a high molecular weight polymeric             Nuclear explosive is a device that obtains its
    substance with viscoelastic properties.             explosive force from the release of nuclear
   It is obtained from the milky secretion             energy.
    (latex) of various plants, but the only
                                                        Trinitrotoluene (TNT) is a high explosive.