INTRODUCTION
1 INTRODUCTION
1.1 HistoryThe combination of elements to form complex molecules
have triggered off the most intriguing and fascinating process
called life, the material basis for whose origin was a polymer.
This polymer, called protein, got synthesized in nature from simple
chemical compounds like methane, ammonia and carbon-dioxide.
Meanwhile, polymer had also appeared in their other natural forms
like wood, cotton, cellulose, starch. Starting in 1811, Henri
Bracannot did pioneering work in derivative cellulose compounds,
perhaps the earliest important work in polymer science. Despite
significant advances in synthesis and characterization of polymers,
a correct understanding of polymer molecular structure did not
emerge until the 1920s. Before that, scientists believed that
polymers were clusters of small molecules (called colloids),
without definite molecular weights, held together by an unknown
force, a concept known as association theory. In 1922, Hermann
Staudinger proposed that polymers consisted of long chains of atoms
held together by covalent bonds, an idea which did not gain wide
acceptance for over a decade and for which Staudinger was
ultimately awarded the noble prize. Most commercially important
polymers today are entirely synthetic and produced in high volume
on appropriately scaled organic synthetic techniques. Synthetic
polymers today find application nearly every industry and area of
life. Polymers are widely used as adhesives and lubricants, as well
as structural compounds for products from childrens toys to
aircraft.
1.2 MONOMERA monomer (from Greek mono one and mer part) is a
small molecule that may become chemically bonded to other monomers
to from a polymer. Monomer is the raw material for a basic
polymerization reaction. Synthetic large molecules are made by
joining together thousands of small molecular units known as
monomers. The process of joining molecules is called polymerization
and the number of these repeating units in the long molecules is
known as degree of polymerization.
1.3POLYMERThe word polymer is derived from the classical Greek
words poly meaning many and mer meaning parts. Simply stated, a
polymer is a long chain molecule that is composed of a large number
of repeating units of identical structure. They are complex and
giant molecules and are different from low molecular weight
compounds like, say, common salt. Polymers are different from
metals in the sense that their structure consists of very long
chain molecules.
1.4CLASSIFICATION OF POLYMERSa. Natural & Synthetic
polymerb. Organic & Inorganic polymerc. Thermoplastic &
Thermoset polymerd. Plastic, Elastomers, Fibers, & Liquid
resins.
HIERACHY OF POLYMER CLASSIFICATION
A characteristic feature of todays modern technology and market
oriented economy is the excessive and exponentially increasing
usage of polymer composites in all fields of industry. The reason
for this phenomenon can be explained by the favorable price/weight
ratio.
1.4.1NATURAL POLYMERNatural polymeric materials such as shellac,
amber, wool, silk and natural rubber have been used for centuries.
A variety of other natural polymers exist, such as cellulose, which
is the main constituent of wood and paper.
1.4.2SYNTHETIC POLYMERThe list of synthetic polymers includes
synthetic rubber, phenol formaldehyde resin (or Bakelite),
neoprene, nylon, polyvinyl chloride (PVC or vinyl), polystyrene,
polyethylene, polypropylene, polyacrylonitrile, PVB, silicone, and
many more.
1.4.3THERMOPLASTICSThermoplastics are prepared by addition
polymerization. They are straight chain are (or) slightly branched
polymers and various chains are held together by weak vanderwalls
forces of attraction. Thermoplastics can be softened on heating and
hardened on cooling. They are generally soluble in organic
solvents.ExamplePolyethylene, Polypropylene etc.,
1.4.4THERMOSET PLASTICSThermosetting plastics are prepared by
condensation polymerization. Various polymer chains are held
together by strong covalent bonds (called crosslinks).
Thermosetting plastics get harden on heating and once harden, they
cannot be softened again. They are insoluble in organic
solvents.ExampleBakelite, polyester etc.,
1.5POLYMERIZATIONPolymers are high molecular weight compounds
whose structures are made up of large number of simple repeating
units. The repeating units are usually obtained from low molecular
weight compounds referred to as monomers. The reaction by which
monomers are converted into polymers is known us
polymerization.
Example
Polymers which are synthesized from only one kind of monomer are
called Homopolymer. Polymers which prepared from more than one kind
of monomers are called Copolymers.
1.6EFFCTS OF STRUCTURE ON PROPERTIES OF POLYMERS
1.6.1STRENGTHThe strength of the polymer depends upon following
three factors Attractive force Slipping power Molecular weight
Attractive forcesStrength of linear or branched polymers exhibit
weak vanderwalls forces and its strength can be enhanced by
introducing polar groups like OH, -COOH, etc., Strength of cross
linked polymers exhibit strong covalent bond forces.
Molecular weightStrength of the polymers increased by increasing
their chain length or by increasing their molecular weight.
Slipping powerIt deals with movement of one molecule over the
another molecule.
Example Polyethylene has high slipping power which leads to
lower strength of the molecule. PVC has less slipping power due to
their restriction of movement by the presence of bulkier chlorine
groups, results in higher strength of the molecule.
1.6.2PHYSICAL STATES OF POLYMERS
Amorphous StateThe amorphous state of a polymer exhibits random
arrangement of a molecule which is easily get affected by external
heat and pressure. During processing, they undergo small volumetric
changes when melting or solidifying.
ExamplePolycarbonate, Polystyrene.
Crystalline StateA small region of macromolecules materials in
which portions of large molecules are arranged in regular way is
called crystalline. During processing, they tend to develop higher
strength in the direction of molecules. Since commercially perfect
crystalline polymers are not produced, they are identified
technically as semi crystalline.
ExamplePolypropylene, Polytetrafluoroethylene (TEFLON).
1.6.3EFFECT OF CHEMICAL RESISTANCE
The chemical group has its effect on the properties of polymer
in the form of polar and non-polar groups. Polar groups soluble
only in polar solvents whereas non polar groups soluble in
non-polar solvents. Polar groups are insoluble in non-polar
solvents.
1.6.4EFFECT OF GLASS TRANSITION TEMPERATURE (Tg)
Owing to the Brownian movement of the molecule, it get freezen
on cooling and it get unfroze on heating. As the temperature is
increased, the localized units (chain segments) within the long
chain first mobilized before the whole molecules starts moving. The
molecules start moving after that fixed position activating
Brownian movement.
The Brownian movement becomes progressively more vigorously and
molecules diffused all over randomly. Low molecular weight
substance in the condense state is called as,
i. The first without Brownian movement, but with long range
order when stress transfer phenomenon is possible (the state is
called solid) or segmental motion.
ii. The second with Brownian movement, without long range order
and with energy dissipation (the state is called liquid) or
molecular motion.
1.7POLYPROPYLENEPolypropylene (PP), also known as polypropene,
is a thermoplastic polymer used in a wide variety of applications
including packaging and labeling, textiles (e.g., ropes, thermal
underwear and carpets), stationery, plastic parts and reusable
containers of various types, laboratory equipment, loudspeakers,
automotive components, and polymer banknotes. An addition polymer
made from the monomer propylene, it is rugged and unusually
resistant to many chemical solvents, bases and acids.
Structural formula :
Molecular formula : C3H6 IUPAC name : Poly(propene) Other names
: Polypropylene, Polypropene, Polipropene 25 [USAN], Propene
polymers, Propylene polymers, 1-Propene Density : 0.91 to 1.23
g/cm3 (57 to 77 lb/ft3) Melting point : 176 C Specific Heat
Capacity : 1230 to 1900 J/kg-K Glass Transition Temperature : -20 C
(0 F) HDT (At 264 psi) : 90 C (190 F) HDT (At 66 psi) : 110 C (230
F) Thermal conductivity : 0.15 W/m-K Water absorption (After 24
hours) : 0.01 %
1.8FILLERSFillers are particles added to material (plastics,
composite material, concrete) to lower the consumption of more
expensive binder material or to better some properties of the
mixtured material. Worldwide more than 53 million tons of fillers
with a total sum of approximately 16 billion are used every year in
different application areas, such as paper, plastics, rubber,
paints, coatings, adhesives and sealants. As such, fillers,
produced by more than 700 companies, rank among the world's major
raw materials and are contained in a variety of goods for daily
consumer needs.
1.8.1CALCIUM CARBONATECalcium carbonate is formed by three main
elements are carbon, oxygen and calcium. It is a common substance
found in rocks in all parts of the world, and is the main component
of shells of marine organisms, snails, coal balls, pearls, and
eggshells. Calcium carbonate is the active ingredient in
agricultural lime, and is created when calcium ions in hard water
react with carbonate ions creating lime scale. It is commonly used
medicinally as a calcium supplement or as an antacid, but excessive
consumption can be hazardous.
Structural formula :
Molecular formula : CaCO3 IUPAC name : Calcium carbonate Other
names : Limestone, calcite, aragonite, chalk, marble, pearl, oyster
Molar mass : 100.0869 g/mol Appearance : Fine white powder, chalky
taste Odor : odorless Density : 2.711-2.83 g/cm3 Melting point :
1339 C Boiling point : Decomposes Flash point : 825 C Refractive
index : 1.59
1.8.2TITANIUM DIOXIDETitanium dioxide, also known as titanium
(IV) oxide or titania, is the naturally occurring oxide of
titanium, chemical formula TiO2. When used as a pigment, it is
called titanium white, Pigment White 6 (PW6), or CI 77891.
Generally it is sourced from ilmenite, rutile and anatase. It has a
wide range of applications, from paint to sunscreen to food
colouring.
Structural formula : Molecular formula : TiO2 IUPAC name :
Titanium dioxide Other names : Titania, Rutile, Anatase, Brookite
Molar mass : 79.866g/mol Appearance : White solid Odor : Odorless
Density : 4.23g/cm3 (Rutile), 3.78g/cm3 (Anatase) Melting point :
1,843 C Boiling point : 2,972C Solubility in water : Insoluble
Refractive index : 2.488 (anatase), 2.583 (brookite), 2.609
(rutile) Flash point : Non-flammable1.8.3ALUMINIUM
SILICATEAluminium silicate (or aluminum silicate) is a name
commonly applied to chemical compounds which are derived from
aluminium oxide, Al2O3 and silicon dioxide, SiO2 which may be
anhydrous or hydrated, naturally occurring as minerals or
synthetic. Aluminium silicate is a type of fibrous material made of
aluminium oxide and silicon dioxide, (such materials are also
called aluminosilicate fibers). These are glassy solid solutions
rather than chemical compounds. The compositions are often
described in terms of% weight of alumina, Al2O3 and silica, SiO2.
Temperature resistance increases as the% alumina increases. These
fibrous materials can be encountered as loose wool, blanket, felt,
paper or boards.
Structural formula :
Molecular formula : Al2SiO5 Molecular mass : 162.0456 g/mol
SCOPE OF THE WORK
2.1SCOPE OF THE WORKTo determine the mechanical and physical
properties of poly(propylene) filled with various types of
inorganic fillers. And compare the mechanical and physical
properties of filled poly(propylene) with various types of
inorganic fillers.13
