Lesson 1, 2: History, Molecular Origin Flashcards
Macromolecule (long molecules) built of small covalently bonded units called monomers
Polymer
Monomers in greek word is ___ means ____
“mer”, part
Small units repeated throughout the macromolecule chain
Monomers
The macromolecules are bonded together by ___ or ___
weak Van der Waals and hydrogen (secondary bonds), or additional covalent cross-links
Most polymers are ___ and formed from ___
Organic, hydrocarbon molecules
Each C atoms has ___ electrons that participate in covalent bonding, each H has ___ bonding electron
4, 1
A single covalent bond exists when ____
Each of the 2 bonding atoms contribute one electron
Double and triple bonds between 2 carbon atoms
Involve the sharing of 2 and 3 pairs of electrons
Molecules that have double, and triple covalent bonds are termed
Unsaturated
Unsaturated means
Each carbon us not bonded to maximum (4) other atoms
For saturated hydrocarbon
All bonds are single ones, and no new atoms may be joined w/o the removal of others
Molecule that combines with other mol of the same/different type to form polymer
Monomer
Oligomer is
Low molecular weight polymer, contains atleast 2 monomer units
Oligomer of polyethylene
Hexatriacontane
Specifies the length of polymer molecule
Degree of polymerization
In DOP, n means
Number of repeating units strung together in the polymer chain (mol)
A ___ degree of polymerization is normally reqd for a matl to develop useful properties
High
Dimensionless quantity given by the sum of the atomic weights in the mol formula
Molecular weight
Relation between DOP and MW of the same macromolecule is…
M=(DP)Mo
Mo= formula weight of the repeating units
Classification of Polymers
Based on origin
Based on polymer structure
Based on polymerization mechanism
According to thermal processing behavior
Based on preparative technique
Classification of polymer Based on origin
Natural vs synthetic polymers
Wood, rubber, cotton, leather, wool, silk, protein, enzymes, starches, cellulose is an example of
Natural polymers
Fibers , elastomers, plastics, adhesives
Synthetic polymers
Classification based on polymer structure
A. Linear, Branched or cross-linked, network vs functionality
B. AMORPHOUS OR CRYSTALLINE
C. HOMOPOLYMER OR COPOLYMER
D. FIBERS, PLASTICS, OR ELASTOMERS
Interlinking capacity, or the number of sites it has available for bonding with other mol under specific pply conditions
Functionality
A molecules can be classified as ___, ___, and ___ depending on whether it has one, two, or greater thwn two sites available
Monofunctional, bifunctional, and polyfunctional
Repeat units are joined together end to end in single chains.
Linear polymers
These long chain are flexible and can be flexible mass spaghetti
Linear polymers
Common examples of LP
PE, PVC, PS, and Polyamides
___ are generally more rigid
Linear polymers
Branched polymers
Have side chains or branches growing out from the main chain
The side chains or
branches are made of the same repeating units as the
main polymer chains (T or F)
T
In ___ adjacent linear
chains are joined one to another at
various positions by covalent bonds
crosslinked polymers
✓Crosslinks tend to be ___ in
nature
permanent
✓Common examples of Cross-linked polymers
Bakelite,
melamine, epoxies, bulk molding
compounds, rubber, and various
adhesives
✓Multifunctional monomers forming
three or more active covalent bonds
make three dimensional networks
and are termed
Network polymers
✓These materials have distinctive
mechanical and thermal properties
network polymers
Network polymers that have distinctive
mechanical and thermal properties
epoxies, polyurethanes, and
phenol-formaldehyde
material
exhibits organized and tightly packed molecular
chains
Crystalline polymers
have good strength &
wear, and good chemical resistance, but they typically lack in impact resistance
crystalline polymer
✓Examples of crystalline polymers include
polyethylene, polyacrylonitrile, poly(ethylene
terephthalate), and polytetrafluoroethylene.
polymers that have no
crystalline regions and no uniformly packed molecules.
✓Amorphous polymers
Amorphous polymers are polymers that are
composed of amorphous regions where molecules
are ____ arranged.
randomly
✓Natural rubber latex and styrene-butadiene rubber
(SBR are hood examples of
amorphous polymers
✓The ____ is a measure of the degree of order or
orientation in a crystal
degree of crystallinity
The DOC ranges from 0 to 100%, where 0% represents
an ____, and 100% represents a perfectly ____.
amorphous material, crystalline
material
✓When all of the repeating units along a chain are of
the same type, the resulting polymer is
Homopolymer
✓The purpose of homopolymers is ____
to produce a
polymer that has increased mechanical properties.
These enhanced mechanical properties in homopolymer include
_____
tensile strength, stiffness, impact resistance, and
short-term creep resistance.
✓The types of homopolymers include
polyvinyl
chloride, polyethylene, polypropylene,
polycarbonate, polyester, nylon 6, nylon 11,
polytetrafluoroethylene, and styrene.
A ___ is a polymer made up of more
than one type of monomer unit.
copolymer
polymerizing
two or more types of monomer together in
a process
Copolymerization
Copolymers produced in copolymerization are
sometimes also referred to as
biopolymers
✓The purpose of creating a copolymer is ____
to
manufacture a polymer with more desirable
properties.
typically experience
a lower crystallinity, higher glass transition temperature, and improved solubility.
Copolymers
In structure of polymers, Representing two different mers by A and B, what is this
ABBABBBAABBAABAAABBA
random copolymer
There are three other copolymer structures
alternating, block, and graft copolymer structures
In the ____, the two mers alternate in a regular fashion along the polymer chain
ABABABABABAB
alternating copolymer
____ is a linear polymer with one or more long uninterrupted sequences of each mer in the chain -AAAAAAAAAABBBBBBBBBB
block copolymer
A ____ is a branched copolymer with a backbone of one type of mer and
one or more side chains of another mer :
AAAAAAAAAA
B
B
B
B
graft copolymer
linear polymers with high
symmetry and high intermolecular forces that result usually from the presence of polar groups.
Fibers
characterized by high modulus, high tensile strength, and moderate extensibilities
Fibers
Examples of fibers are
Polyester, Nylon, Spandex, Kevlar, Rayon, Acetate, Acrylic, Lastex, Polypropylene
molecules with irregular structure, weak intermolecular attractive forces, and very flexible polymer chains.
Elastomers
✓____ are polymers that have viscosity and elasticity and therefore are known as ____.
Elastomers; viscoelasticity
inherit the unique property of
regaining their original shape and
size after being significantly stretched.
Elastomers
Examples of elastomers
rubber, polyurethanes, polybutadiene
Examples of elastomers are
rubber, polyurethanes, polybutadiene
A ____ is a polymer, typically modified with
additives, which can be molded or
shaped under reasonable conditions of pressure and temperature.
plastic material
7 types of plastics
PET, HDPE, LDPE, PVC, PP, PS, Others
CLASSIFICATION BASED ON POLYMERIZATION MECHANISM
CONDENSATION POLYMERS
ADDITION POLYMERS
_____ are formed from a series of reactions, often of condensation type, in which any two species can react at any time leading to a larger molecule.
Condensation polymers
_____ form of a step-growth
polymerization where smaller
molecules or monomers react with
each other to form larger structural
units (usually polymers) while
releasing by-products such as water or methanol molecule. The by-
products are normally referred to as _______.
Condensation polymers; condensate
In condensation polymers, the reaction can occur between any two growing polymer molecules and can be represented by
P_m + P_n 《》P_(m+n) + W
Several _____ include nylon, kevlar, polyester, Bakelite, Melamine, polycarbonates, polyurethanes,
epoxies.
synthetic condensation polymers
_____ are produced by reactions in which monomers are added one after another to a rapidly growing chain
Addition polymers
✓Examples of addition polymers are
polystyrene, polyethylene,
polyacrylonitrile, polymethyl methacrylate, and polyvinyl chloride.
Addition polymers can be schematically represented as
P_n + M 《》P_(n+1)
CLASSIFICATION OF POLYMERS ACCORDING TO THERMAL PROCESSING BEHAVIOR
THERMOPLASTICS
THERMOSETS
✓Plastics that soften when heated and
become firm again when cooled. This is
the more popular type of plastic because
the heating and cooling may be repeated and the ___ may be reformed.
thermoplastic
Most linear polymers and those having some branched structures with flexible chains are ___
thermoplastic
✓Examples of common _____ include polyethylene, polystyrene, poly(ethylene terephthalate), and poly(vinyl chloride), polypropylene, polycarbonate, nylon, Teflon.
thermoplastic polymers
These are plastics that soften when heated and can be molded but harden permanently. They will decompose when reheated.
THERMOSETS
Thermosets usually exist initially as liquids called _____; they can be shaped into desired forms by the application of heat and pressure but are incapable of undergoing repeated cycles of softening and hardening
prepolymers
Principal examples of thermosets include
epoxy, phenol-formaldehyde resins, and unsaturated polyesters.
An example of thermoset which is used in toasters, handles for pots and pans, dishes, electrical outlets
and billiard balls.
Bakelite
A ___ is a polymer that is irreversibly hardened by heat
Thermosetting plastic of thermoset
✓In _____, only the monomer (and possibly catalyst and initiator, but no solvent) is fed into the reactor. The monomer undergoes polymerization, at the end of which a solid mass is removed as the _____.
bulk polymerization; polymer product
✓Example of polymers that can be produced by bulk polymerization are
polyvinyl chloride (PVC), polyethylene (PE), Polypropylene (PP), Polyethylene terephthalate (PET), Polystyrene (PS), Polyvinylidene chloride (PVDC),
Polytetrafluoroethylene (PTFE).
_____ involves polymerization of a
monomer in a solvent in
which both the monomer
(reactant) and polymer
(product) are soluble.
Solution polymerization
It is used in the production of
polyacrylonitrile, polyacrylic
acid, polyacrylamide,
polyvinyl alcohol,
polybutadiene.
Solution polymerization
_____ refers to polymerization in an aqueous medium with the monomer as the dispersed phase.
Consequently, the polymer resulting from such a system forms a solid dispersed phase.
Suspension polymerization
✓Several commercially important vinyl copolymers are manufactured using ____, including polystyrene (general purpose, expandable and
high impact), polymethyl methacrylate, polyvinyl acetate, styrene–acrylonitrile (SAN)
copolymers, acrylonitrile–butadiene–styrene
(ABS) copolymers, and polyvinyl chloride (PVC).
suspension polymerization
____ is similar to suspension polymerization, but the initiator is located in the aqueous phase (continuous phase) in contrast to the monomer (dispersed phase) in suspension polymerization.
Emulsion polymerization
BULK PROPERTIES OF POLYMERS
TENSILE STRENGTH
YOUNG’S MODULUS OF ELASTICITY
TRANSPORT PROPERTIES
PURE COMPONENT PHASE BEHAVIOR (MELTING POINT, GLASS TRANSITION)
The _____ of a material
quantifies how much stress the
material will endure before failing.
tensile strength
_____ increases with polymer chain length.
Tensile strength
quantifies the
elasticity of the polymer.
Young’s Modulus
defined as the ratio of rate of
change of stress to strain
Young’s Modulus
____ such as diffusivity relate to how rapidly
molecules move through the polymer matrix.
Transport properties
very important in many applications of polymers for films
and membranes.
Transport properties
PURE COMPONENT PHASE BEHAVIOR are
Melting pt, glass transition
The _____ when applied to polymers suggests not a solid-liquid phase transition but a transition from a crystalline or semi-crystalline phase to a solid amorphous phase.
melting point
___ is a crucial physical
parameter for polymer manufacturing, processing, and use.
glass-transition temperature (Tg)
Below ____, molecular motions are _____, and polymers are ____.
glass-transition temperature (Tg)
frozen
brittle and glassy
Above ____, molecular motions are ___, and polymers are _____
Tg, activated, rubbery and viscous.
A __ is a substance composed of macromolecules.
polymer
molecule of high relative molecular mass, the structure of which essentially comprises the multiple repetition of units derived, actually or conceptually, from molecules of low relative molecular mass.
macromolecules
polymer stems from the Greek roots
poly (many) and meros (part).
Polymer designates a molecule made up by the repetition of some simpler unit called a ___.
mer
long-chain molecule that is composed of a large number of
repeating units of identical structure.
Polymer
___ prepared by joining a large number of small molecules called
___.
Polymers, monomers
Polymer have MW of
More than 5000
1833 in historical devt of polymers
Jons Jacob Berzelius ( poly + meros )
1920 in hist devt of polymers
Modern definition by Hermann Staudinger IUPAC
definition
Year where the Horners Company of London recorded the use of horn and tortoiseshell as the predominant early natural plastic.
1284
British explorers discovered the Ancient Mayan civilization in
Central America. The Mayans are assumed to be among the first to find an application for polymers, as their children were found playing with balls made from local rubber trees.
1500s
In ___, _____ (1766-1843) uses rubber gum for making waterproof garments
1823, Charles Macintosh
In ____, ____ (1795-1871) identified a compound extracted from
wood which he named cellulose.
1838, Anselme Payen
In ____, ____ (1789- 1856) discovered polystyrene.
1839, Eduard Simon
In ____, ____ (1800-1860) discovered vulcanization by combining ____ and heating it to ____
1839, Charles Goodyear, natural rubber with sulfur, 270°F
Goodyear patents the vulcanization of rubber
1844
In ___, ___ (1799-1868) synthesized nitrocellulose (nitrated cellulose)
1846, Christian Friedrich Schonbein
In __, ___ (1813-1890) patents the first thermoplastic , _____, made by adding plasticizer to nitrocellulose
1856 - Alexander Parkes, (Parkesine)
In ____, the Hyatt brothers (John Wesley and Isaiah) in America produced ____ from ___. This was unstable and subsequently led to the development of ___.
1868, celluloid, cellulose nitrate mixed with camphor, cellulose acetate
In ___, ___ (1846-1896) was the one of the first people to create
polyvinyl chloride (PVC).
1872, Eugen Baumann
1892, ____ was developed by ___
Viscose silk (rayon), Cross and Bevan
In ___ , ____ produced phenol-formaldehyde, the first truly synthetic plastic, Bakelite. Cast with pigments to resemble onyx, jade,
marble, and amber, it has come to be known as ____
1907, Leo Baekeland, phenolic resin
In ___, ____ discovered polyvinyl acetate and patented the
manufacturing process for PVC.
1912 - Fritz Klatte
_____ discovered how to make sheets and adhesives from poly(vinyl chloride)-and the “vinyl age” began.
1926 - B. F. Goodrich
In ____, ____, the first transparent sticky tape invented in US by 3M
Company
1930 - ‘Scotch’ tape
In ____, the first industrially practical ____ synthesis was discovered (again by accident) by _____ at the Imperial Chemical Industries (ICI) works in Northwich, England.
1933, polyethylene, Eric Fawcett and Reginald Gibson
In 1933, _____ were developed.
Melamine formaldehyde resins
In ___, Wallace Carothers, working for DuPont invented ____. DuPont named this product ____.
1935, polyhexamethylene-
adipamide, nylon
Wallace Carothers – Father of ____
Synthetic Polymer Science
In ____, the Wulff Brothers in Germany produced ____
1936, commercially viable polystyrene
In ___, ___ patented polyurethane.
1937, Otto Bayer
In ___, ___ working for DuPont, accidentally discovered _____, tramarked Teflon.
1938, Roy Plunkett, polytetra fluroethylene (PTFE)
In ____, Polyethylene terephthalate (PET), a saturated polyester patented by ____
1941, John Rex Whinfield and James Tennant Dickson.
In year ____ - Textiles, Fashion, Toys, Domestic uses (____ first appearance)
1950s, polyethylene bag
In year ___ – color and design of polymers
1960s and 70s
In what year the Polyethylene terephthalate beverage bottles introduced
1973
In year ____ - High performance plastics
1980s and 90s
In ___ , first ____ was introduced
into UK.
1980, Blue HDPE pressure pipes for potable water
____ Nanotechnology, Airbus A380, iPod
2000 to 2010
In ____ , Nanotechnology applied to polymer and composite
applications
2000s
______ - Scientists at Rice University, Texas have created a new super polymer material that can stop a ___ bullet and seal the hole behind it
Bullet Proof Polymer ,9mm
Developed by the University of Sheffield to mimic ___, a for use in trauma situations where blood is needed quickly
Plastics Blood, haemoglobin
A polymer solar cell that can produce electricity from sunlight by the ____ provides a lightweight, disposable and
inexpensive alternative to traditional solar panels
Plastic Solar Cells, photovoltaic effect
Medical grade and implantable biomaterials such as ____ will be used in neurological applications to help control epilepsy, Parkinson’s disease and brain trauma
Implantable Polymers, PEEK
Space Flights Lightweight carbon composite materials will be
crucial in the realization of sub- orbital tourist spaceflights.
Commercial
Body Parts using plastic materials such as PMMA car parts can be printed at home and doctors can produce replica livers or kidneys for transplant patients.
3D Printed
Organic light-emitting diodes are placed on plastic foil to create electronic devices with flexible displays.
Flexible Plastic Screens
In the future all driverless vehicles will be almost entirely constructed from plastic parts due to the light weighting properties they provide.
Driverless Cars
During the height of COVID-19, plastics companies were called upon to deliver over 50,000 bottles of hand sanitizer per week to the NHS
COVID-19
IMPORTANCE OF POLYMER ENGINEERING IN THE CHEMICAL
ENGINEERING CAREER
- Select the right material and the production process for an
application. - Assess product liability.
- Develop and automate production techniques.
- Design for recyclability.
- Solve problems.
- Challenge and replace traditional materials.
___ was a tragic space shuttle mission occured on ____
The Challenger; Jan 28, 1986
The Challenger was a tragic space shuttle mission that occurred on
January 28, 1986, during the launch of the ____ at the Kennedy Space Center.
Space Shuttle Challenger STS-26
The space shuttle disaster, Challenger, was caused by
an explosion in one of the O-
ring seals, which allowed hot gas to escape into the external fuel tank and cause an explosion.
The Challenger disaster apparently resulted from _____
not choosing quite the right rubber seal for the fuel system. The O-ring seal became rigid and lost its resilience/pliability at low temperatures and resulted in fuel seepage. The hot pressurized gas went to the external fuel tank and cause and explosion
When considering new materials, assess:
Availability
properties
Processability
suitability/functionality, even under extreme conditions
aesthetics and history of the product
environmental impact and health and safety
