Types of plastic

The most plastic are made from petroleum, although natural gas and coal are used partly,
Naphtha, naphtha is a group of various liquid hydrocarbon intermediate oil refining products
used primarily as feedstocks for producing a high octane gasoline component via the catalytic
reforming process. Naphtha is also used in the petrochemical industry for producing olefins in
steam crackers and in the chemical industry for solvent applications.Then naphtha is decomposed thermally into monomers, which are converted into polymer by
polymerization, polymerization means a chain reaction the monomer to bond together to from a long chain of the molecules become high molecular compounds Plastic Classification Generally plastic can classified as shown below

Thermoplastic
A thermoplastic is a material that is plastic or deformable, melts to a liquid when heated and
freezes to a brittle, glassy state when cooled sufficiently. Most thermoplastics are high
molecular weight polymers whose chains associate through weak van der Waals forces
(polyethylene); stronger dipole-dipole interactions and hydrogen bonding (nylon); or even
stacking of aromatic rings (polystyrene). Thermoplastic polymers differ from thermosetting
polymers (Bakelite; vulcanized rubber) which once formed and cured, can never be remelted and remolded.
Many thermoplastic materials are addition polymersList kind of thermoplastics
• Acrylonitrile butadiene styrene (ABS)
• Acrylic
• Celluloid
• Cellulose acetate
• Ethylene-Vinyl Acetate (EVA)
• Ethylene vinyl alcohol (EVAL)
• Fluoroplastics (PTFEs, including FEP, PFA, CTFE, ECTFE, ETFE)
• Ionomers
• Kydex, a trademarked acrylic/PVC alloy
• Liquid Crystal Polymer (LCP)
• Polyacetal (POM or Acetal)
• Polyacrylates (Acrylic)
• Polyacrylonitrile (PAN or Acrylonitrile)
• Polyamide (PA or Nylon)
• Polyamide-imide (PAI)
• Polyaryletherketone (PAEK or Ketone)
• Polybutadiene (PBD)
• Polybutylene (PB)
• Polybutylene terephthalate (PBT)
• Polyethylene terephthalate (PET)
• Polycyclohexylene dimethylene terephthalate (PCT)
• Polycarbonate (PC)
• Polyhydroxyalkanoates (PHAs)
• Polyketone (PK)
• Polyester
• Polyethylene (PE)
• Polyetheretherketone (PEEK)
• Polyetherimide (PEI)
• Polyethersulfone (PES)- see Polysulfone
• Polyethylenechlorinates (PEC)
• Polyimide (PI)
• Polylactic acid (PLA)
• Polymethylpentene (PMP)
• Polyphenylene oxide (PPO)
• Polyphenylene sulfide (PPS)
• Polyphthalamide (PPA)
• Polypropylene (PP)
• Polystyrene (PS)
• Polysulfone (PSU)
• Polyvinyl chloride (PVC)
• Polyvinylidene chloride (PVDC)
• Spectralon

Thermosetting
plastics are polymer materials that cure, through the addition of energy, to a stronger form. The energy may be in the form of heat (generally above 200 degrees Celsius), through a chemical reaction (two-part epoxy, for example), or irradiation.Thermoset materials are usually liquid, powder, or malleable prior to curing, and designed to be
molded into their final form, or used as adhesives.The curing process transforms the resin into a plastic or rubber by a cross-linking process.
Energy and/or catalysts are added that cause the molecular chains to react at chemically active
sites (unsaturated or epoxy sites, for example), linking into a rigid, 3-D structure. The cross
-linking process forms a molecule with a larger molecular weight, resulting in a material with a
higher melting point. During the reaction, when the molecular weight has increased to a point so
that the melting point is higher than the surrounding ambient temperature, the material forms
into a solid material. Subsequent uncontrolled reheating of the material results in reaching the
decomposition temperature before the melting point is obtained. A thermo set material cannot be melted and re-shaped after it is cured.Thermo set materials are generally stronger than thermoplastic materials due to this 3-D network of bonds, and are also better suited to high-temperature applications up to the decomposition temperature of the material. They do not lend themselves to recycling like thermoplastics, which can be melted and re-molded.

Crystalline plastic
Some molecules of linear molecule compound can gather regulary, this type of plastic called the
crystalline plastic, not all the molecules crystallized, and the ratio of crystalline depend on
cooling condition, pre heating and others, sample of this type plastic are :
• Polyacetal resin (POM)
• Polymide resin (PA)
• Polypropylene resin (PP)

Armorphous plastic
Unlike crystalline plastic, the molecules of these plastic cannot gather regulary,this plastic
which is not crystalline, generally transmits light and has low solvent resistance sample of
this type plastic are :
• All the thermosetting plastic
• acrylic resin (PMMA)
• polystyrene (PS)

Polymer
A polymer is a substance composed of molecules with large molecular mass consisting of repeating structural units, or monomers, connected by covalent chemical bonds. its compounds obtained by polmerization, they are the base of plastics, if they are mixed with fillers, stabilizers they mixtures became moldable plasticspolimer can divide into-A homopolymer molecule is derived from a single monomer species, such as polyethylene or polymethylmethacrylate.-A copolymer molecule is derived from two or more monomer species, such as ethylene-vinyl
acetate or DNA. Depending on the arrangement of the individual monomers, a copolymer molecule may be classified by terms such as alternating, random, or statistical.

Manomer
is a small molecule that may become chemically bonded to other monomers from which polymers can be made, its a raw material of polymer this process also known as polymerization. a molecule of any of a class of compounds from polimer, mostly organic, that can react with other molecules of the same or other compound to form very large molecules, or polymers. The essential feature of a monomer is polyfunctionality, the capacity to form chemical bonds to at least two other monomer molecules Examples of monomers are hydrocarbons such as the alkene and arene homologous series. Here hydrocarbon monomers such as phenylethene and ethene form polymers used as plastics like poly(phenylethene) (commonly known as polystyrene) and poly(ethene) (commonly known as polyethylene
or polythene). Other commercially important monomers include acrylic monomers such as acrylic acid, methyl methacrylate, and acrylamide

Copolymer
a polymer consisting of two or more different monomers, The structural units derived from the different monomers may be present in regular alternation or in random order, Commercially relevant copolymers include ABS plastic, SBR, styrene-isoprene-styrene (SIS) and ethylene-vinyl acetate.

Homopolymer
A polymer formed from a single monomer, an example is polyethylene, formed by polymerization of ethylene A homopolymer is constructed of identical monomers or macromolecules consisting of a single type of building unit, his is in contrast to a copolymer where the polymer contains at least two monomers. It is frequently referred to simply as a polymer