2. Thermoplastics
Polymers soften or melt on heating are called
Thermoplastic Polymers
Characterized by liner chain molecules
Ex: Polyesterene , Polyethylene
3. Definition-Thermosetting Polymer
A thermosetting polymer is a prepolymer in a soft
solid or viscous state that changes irreversibly into
an infusible insoluble polymer network by curing.
Curing can be induced by action of heat or suitable
radiation or both .
A cured thermosetting polymer is called Thermostat
4. DIFFERENCES
Thermosets Thermoplastics
Resin Cost is low Resin Cost is High
Exhibits moderate
Shrinkage Is low
shrinkage
Exhibits good resistance Poor resistance to fluids
to fluids and solvents and solvents
Interlaminar fracture Interlaminar fracture
toughness is low toughness is high
5. DIFFERENCES
Thermosets Thermoplastics
Long processing cycles
Low processing cycle time
Poor Recycling Recyclability and
capabilities environmental protection
More difficult to repair
High reparability
ability
Good wetting and
Draping difficulties
adhesion to reinforcement
8. EPOXY
The term epoxy is a general
description of a family of polymers
which are based on molecules that
contain epoxide groups
An epoxide is a cyclic ether with three
ring atoms. This ring approximately
defines an equilateral triangle, which
makes it highly strained
An epoxide group is an oxirane
structure, a three-member ring with
one oxygen and two carbon atoms.
9. EPOXY
A polymer formed by reacting epoxide units is called a
polyepoxide or an epoxy.
Epoxy is a copolymer; that is, it is formed from two
different chemicals. These are referred to as the
"resin" or "compound" and the "hardener" or
"activator".
Epoxy, also known as PolyEpoxide, is a thermosetting
polymer formed from reaction of an Epoxide "resin"
with Polyamine "hardener".
.
10. EPOXY
Epoxies are polymerizable thermosetting resins
containing one or more epoxide groups curable by
reaction with amines, acids,amides, alcohols, phenols,
acid anhydrides, or mercaptans.
The polymers are available in a variety of viscosities
from liquid to solid.
11. EPOXY
The Common starting material :
Diglycidyl Ether of Bisphenol A(DGEBA) which
contain two epoxide groups , one at each end of the
molecule
12. EPOXY
Most common epoxy resins are produced from a
reaction between Epichlorohydrin and Bisphenol-A
The hardener consists of polyamine monomers, for
example Triethylene tetramine (TETA).
When these compounds are mixed, the amine
groups react with the epoxide groups to form a
covalent bond.
Each NH group can react with an epoxide group
from distinct prepolymer molecules, so that the
resulting polymer is heavily crosslinked, and is thus
rigid and strong
13. Manufacturing of Epoxy Resin
Diluents – Reduce the viscosity
Flexibility agents – make epoxy flexible
Other agents – Protection against UV
Curing agents – organic amino compounds
(To obtain cross linking by introducing chemicals
that react with the epoxy and hydroxyl groups
between adjacent chains )
14. EPOXY
Crosslinking :Stiffness, strengh increases but
toughness decreases
B-Stage:
An epoxy before it is fully cross linked is said to be in
stage B
In stage B , epoxy has characteristic tackiness
The curing reaction can be lowered by lowering the
reaction temperature
15. PROPERTIES OF EPOXY
Make an excellent matrix material because of their
versatility,
• Good handling characteristics,
• Low shrinkage,
• Excellent adhesive properties,
• Flame resistant,
• Good chemical resistance,
• Good mechanical properties including toughness,
• Offer considerable variety for formulating Prepreg
resins,
• Hot molding (cold molding rarely),
• High smoke emission,
• Curing temperature is 120-175°C (250-3500F), and
• No by-products formed during cure
16. EPOXY
Disadvantages :
Brittleness and reduction in the properties in the
presence of moisture
Slower processing time then polyester
More expensive then polyesters
17. EPOXY –Applications
Used in Aircraft Construction
Croyogenic applications
Epoxy-nylon, Epoxy-amide have good retention of both tensile
strength and elongation at cryogenic temperatures and are
usually the only materials that will work well at these
temperatures.
Bridge Structures :
Epoxy reinforced concrete
Carbon reinforced Epoxy Structures
Glass reinforced Epoxy Structures
19. POLYESTER (Thermosetting)
Polyester is a category of polymers which contain
the ester functional group in their main chain.
The term "polyester" as a specific material most
commonly refers to polyethylene terephthalate (PET)
Esters are chemical compounds consisting
of a carbonyl adjacent to an ether linkage
20. POLYESTER
A condensation reaction between the
GLYCOL ( Ethylene, Propylene, diethylene glycol)
+
Unsaturated Dibasic Acid
=
Linear Polyester
21. POLYESTER
PET(polyethylene terephthalate) is made from
Ethylene Glycol and Terephthalic Acid by splitting out
water molecules (-H from alcohol and -OH from acid.
The units are joined to make the ester group.
22. POLYESTER
A simple representation is -[A-B-A-B-A-B]-.
24. Polyester- Properties
Hard strong and extremely tough
High abrasion resistance
Low coefficient of friction
Good chemical resistance
Good surface appearance
Electrical properties are stable upto the rated
temperature limits
25. Polyester-Advantages
The relatively easy accessible raw materials.
The very well understood and described simple
chemical process of polyester synthesis.
The low toxicity level of all raw materials and side
products during polyester production and processing
26. Polyester-Advantages
The possibility to produce PET in a closed loop at
low emissions to the environment
The outstanding mechanical and chemical properties
of polyester
The recyclability
The wide variety of intermediate and final products
made of polyester.
28. POLYESTER – APPLICATIONS
It can also be made into textile fibers known as Dacron and accounts
for 50% of all fibers used to make clothing.
Blended with cotton, made into no-iron clothes.
Industrial polyester fibers, yarns and ropes are used in tyre
reinforcements, fabrics for conveyor belts, safety belts, coated fabrics
and plastic reinforcements
Polyesters are also used to make bottles, films, tarpaulin, canoes, liquid
crystal displays, holograms, filters, dielectric film for capacitors, film
insulation for wire and insulating tapes
30. Nylon Matrices
Nylon is a generic designation for a family of
synthetic polymers known generically as polyamides
Nylon is a thermoplastic, silky material, first used
commercially in a nylon-bristled toothbrush.
Nylon is made of repeating units linked by amide
bonds and is frequently referred to as polyamide
(PA)
31. NYLON
Chemically, nylon is formed by chains of amide
molecules. The chains are arranged parallel to each other,
attached by hydrogen bonds.
To make nylon's fibers strong, a polymerizing process
must occur that allows the molecules to combine without
retaining any water. In effect the process of making nylon
is a condensation reaction.
Nylon 6,6
32. NYLON –CHEMISTRY
Nylons are condensation copolymers formed by reacting
equal parts of a diamine and a dicarboxylic acid, so that
amides are formed at both ends of each monomer in a
process analogous to polypeptide biopolymers
A molecule of water is given off and the nylon is
formed. Its properties are determined by the R and R'
groups in the monomers
33. NYLON - Characteristics
Variation of luster: nylon has the ability to be very lustrous, semilustrous or
dull.
Durability: its high tenacity fibers are used for seatbelts, tire cords, ballistic
cloth and other uses.
High elongation
Excellent abrasion resistance
Highly resilient (nylon fabrics are heat-set)
Paved the way for easy-care garments
High resistance to insects, fungi, animals, as well as molds, mildew, rot and
many chemicals
Used in carpets and nylon stockings
Melts instead of burning
Used in many military applications
Good specific strength
Transparent to infrared light (−12dB)[3]
34. NYLON –PROPERTIES
Excellent material for machining
Tough, strong, and impact resistant material
Very low coefficient of friction
Abrasion resistant.
Excellent resistance (no attack) to Oils, Bases and
THF
Good resistance (no attack) to Solvents,
Formaldehyde and Alcohols
Limited resistance to Dilute Acids
Poor resistance (not recommended for use with)
Phenols, Alkalis, Iodine and Acids
35. NYLON – APPLICATIONS
Nylon is commonly used in the production of tire
cords, rope, belts, filter cloths, sports equipment and
bristles.
It is particularly useful when machined into bearings,
gears, rollers and thread guides.
Solid nylon is used for mechanical parts such as
machine screws, gears and other low- to medium-
stress components previously cast in metal.
36. NYLON – APPLICATIONS
Engineering-grade nylon is processed by extrusion,
casting, and injection molding.
Solid nylon is used in hair combs.
Type 6,6 Nylon 101 is the most common commercial
grade of nylon, and Nylon 6 is the most common
commercial grade of molded nylon
38. Polypropylene
Polypropylene is a plastic polymer, of the chemical
designation C3H6.
39. Polypropylene- Isotacti
c
Most commercial polypropylene is isotactic and has
an intermediate level of crystallinity between that of
low-density polyethylene (LDPE) and high- density
polyethylene (HDPE)
40. Polypropylene-Types
1. Homopolymer
2. Copolymer
3.Block Copolymer
PP is also used for plastics reinforced constructions. For
this typical application, it is possible to
use two different types of polypropylene.
PP sk is the traditional type polyether-backed but as
standard product, it exist also PP
copolymer polypropylene-backed:
PP-DWU-SK: Homopolymer, permanent-heat resistant,
grey, polyester-backed
PP-C-PK: Copolymer, permanent-heat resistant, grey,
polypropylene- backed
41. Those PP-C-PK sheets have a lot of advantage:
Allows excellent three-dimensional thermoforming
It is not necessary to finish the fabric at welding zones
Better adhesive properties than PP polyester backing
sheets
PP-EL is an electrically conductive homopolymer
polypropylene. This material is treated with
electrically conductive particles which discharge the
static. PP-EL has high surface resistivity and
is ideal for use in potentially explosive atmospheres.
PP-EL-S (special type) includes a flame-retardant
additive
42. Polypropylene-Manufacturing
It is manufactured from the propylene gas in the
presence of catalyst such as titanium chloride
Melt processing of polypropylene can be achieved
by extrusion and moulding
Common extrusion methods
A) Injection moulding
B) Blow moulding
C) Injection stretch moulding
43. Polypropylene-properties
Semi-rigid
Translucent
Good chemical resistance
Tough
Good fatigue resistance
Integral hinge property
Good heat resistance
44. Polypropylene-Applications
Since polypropylene is resistant to fatigue, most
plastic living hinges, such as those on flip-top
bottles, are made from this material
Polypropylene lid of a Tic Tacs box, with a living hinge and the resin
identification code under its flap
45. Polypropylene-Applications
Polypropylene is used in the manufacturing piping
systems; both ones concerned with high-purity and
ones designed for strength and rigidity.
Many plastic items for medical or laboratory use can
be made from polypropylene because it can
withstand the heat in an autoclave
Its heat resistance also enables it to be used as the
manufacturing material of consumer-grade kettles
46. Polypropylene – Applications
Food containers made from it will not melt in the
dishwasher, and do not melt during industrial hot
filling processes.
For this reason, most plastic tubs for dairy products
are polypropylene sealed with aluminum foil (both
heat-resistant materials)
Car batteries, wastebaskets, pharmacy prescription
bottles, cooler containers, dishes are often made of
polypropylene
47. Polypropylene
Polypropylene, highly colorfast, is widely used in
manufacturing carpets, rugs and mats to be used at
home.[17]
Polypropylene is widely used in ropes, distinctive
because they are light enough to float in water
Polypropylene is also used as an alternative to polyvinyl
chloride (PVC) as insulation for electrical cables for LSZH
cable in low-ventilation environments, primarily tunnels.
This is because it emits less smoke and no toxic
halogens, which may lead to production of acid in high-
temperature conditions.
48. Polypropylene-Polyester
For equal mass and construction, polypropylene
rope is similar in strength to polyester rope.
Polypropylene costs less than most other synthetic
fibers.
49. Polypropylene- Applications
Used for plastic moldings, wherein it is injected into a
mold while molten, forming complex shapes at
relatively low cost and high volume; examples
include bottle tops, bottles, and fittings.
It can also be produced in sheet form, widely used
for the production of stationery folders, packaging,
and storage boxes.
The wide color range, durability, low cost, and
resistance to dirt make it ideal as a protective cover
for papers and other materials.
50. Polypropylene
Polypropylene is a major polymer used in
nonwovens, with over 50% usedfor diapers or
sanitary products where it is treated to absorb water
(hydrophilic) rather than naturally repelling water
(hydrophobic).
polypropylene yarn is the lightest fibre of all synthetic
and natural fibers. Final users gain more comfort
because the garments are lighter.
