Chem (Polymers) Flashcards
Molecular compound that can be distinguished
by a high molar mass, ranging into thousands
and even millions of masses and they are made
up of many repeating units.
POLYMER
The root ‘mer’ means ____, and poly means _____. Taken together, the
word polymer can be deconstructed as _____
units, many = many units
Typically, ‘mer’ is referred to as a
_______
monomer
This is a type of polymer that have been around since life itself began
Natural Polymer (cellulose, starch, dna, natural rubber)
were first developed in the
early 20th century, and these polymers
remarkably transformed our world as different
materials can be created with properties that are
ideal for different applications. Examples are
nylon, polyethylene, polyester, teflon, and epoxy.
Synthetic Polymers
It is the starting material for
many synthetic polymers in plastics,
pharmaceuticals, fabrics, and other carbon-
based products.
Crude oil
If a polymer is made up of only type of monomer
(e.g. polyethylene), then it is known as
________
homopolymer Homopolymer
The molecules in polymers are gigantic and
because of their size they are often referred to as
?
macromolecules
The backbone of each of a
carbon- chain polymer is a string of carbon atoms
and within each molecule, the atoms are bound
together by ________
covalent interatomic bonds
It is a stable molecule with two carbon
atoms connected by a double bond. It
is made by the reaction of multiple _______ molecules in the presence of a catalyst.
Ethylene
Molecular weight and shape of a polymer is not
the only basis of its physical characteristics, the
difference in the structure of the molecular chains
must also be considered.
Polyner Structure
_____________ are those in which the repeat
units are joined together end to end in single
chains. These long chains are flexible where each
circle represents a unit.
• There may be extensive Van der Waals and
hydrogen bonding between the chains.
Linear Polymers
The chain packing efficiency is reduced with the
formation of side branches, which results in a
lowering of the polymer density.
Branched Polymer
• Adjacent linear chains are joined one to another
at various positions by covalent bonds.
Cross-linked polymer
The process of crosslinking is achieved either
during ___________ or by a __________.
Synthesis or nonreversible chemical reaction
Multifunctional monomers forming three or
more active covalent bonds; a polymer that js highly cross-linked
Network Polymer
• Properties: transparent, strong, shatter resistant.
Impervious to acids and atmospheric gases. Most
costly of the six.
• Uses: soft-drink bottles, clear food containers,
beverage glasses, fleece fabrics, carpet yarns,
fiber-fill insulation.
Polyethylene Terephthalate (PETE)
Properties: similar to LDPE but more rigid,
tougher, and slightly more dense.
• Uses: opaque milk, juice, detergents, and
shampoo bottles. Also used in buckets, crates,
and fencing materials
Polyethylene (PE)
• Properties: Variable. Rigid if not softened with a
plasticizer. Clear and shiny, but often pigmented.
Resistant to most chemicals, including oils, acids,
and bases.
• Uses: Rigid: plumbing pipe, house siding, charge
cards, and hotel room keys. Softened: garden
hoses, waterproof boots, shower curtains, and iv
tubing.
Polyvinyl Chloride (PVC)
• Properties: translucent if not pigmented. Soft and
flexible. Unreactive to acids and bases. Strong
and tough.
• Uses: bags, films, sheets, bubble wrap, toys, wire
insulation.
Polyethylene (PE)
• Properties: opaque, very tough, good
weatherability. Has high melting point. Resistant
to oils.
• Uses: bottle caps. Yogurt, cream, and margarine
containers. Carpeting, casual furniture, luggage.
Polypropylene (PP)
• Properties: crystal form is transparent,
sparkling, somewhat brittle. Expandable form is
lightweight. Both forms are rigid and degrades in
many organic solvents.
• Uses: crystal form: food wrap, cd cases,
transparent cups. Expandable form: foam cups,
insulated containers, food packaging trays, and
egg cartons.
Polystyrene (PS)
Polymers with very long chains has extremely
____________ but during
_____________ process, not all polymer chains
will grow to the same length.
large molecular weights, polymerization
an alternative
way of expressing average chain size of a polymer.
DP represents the average number of repeat
units in a chain and it is related to the number-
average molecular weight of the polymer.
Degree of Polymerization
