polymer structure

Question 1

those derived from plants and animals

Answer 1

naturally occurring polymers

Question 2

organic materials are__________________

Answer 2

hydrocarbon

Question 3

composed of hydrogen and carbon

Answer 3

hydrocarbon

Question 4

intermolecular bond of polymers

Answer 4

covalent

Question 5

exists when each of the two bonding atoms contributes one electron

Answer 5

covalent

Question 6

Molecules that have double and triple covalent bonds

Answer 6

unsaturated

Question 7

weak hydrogen and van der Waals bonds exist between molecules, and thus these hydrocarbons have relatively low melting and boiling points

Answer 7

paraffine

Question 8

hydrocarbon with the same composition by different atomic arrangement

Answer 8

isomers

Question 9

physical properties of hydrocarbon are independent to its isomer state

Answer 9

false (depend)

Question 10

they are referred to as, macromolecules

Answer 10

polymer molecules

Question 11

it is the backbone of carbon chain polymer

Answer 11

carbon atoms

Question 12

carbon chain polymer is composed of entities called _______________

Answer 12

repeat units

Question 13

it is sometimes called mer

Answer 13

repeat units

Question 14

originates from the Greek word meros, which means “part”

Answer 14

mer

Question 15

small molecule from which a polymer is synthesized

Answer 15

Monomer

Question 16

Have the trade name teflon, belong to the family of polymers called fluorocarbon

Answer 16

Polytetrafluoroethelyne

Question 17

Slight variant of ethylene, in which one of the hydrogen atom is replaced by Cl

Answer 17

Vinyl chloride monomer

Question 18

When all of the repeating units along a chain are of the same type

Answer 18

Homopolymer

Question 19

Chains may be composed of two or more different repeat units

Answer 19

Copolymer

Question 20

monomers have an active bond that may react to form two covalent bonds with other monomers forming a two-dimensional chainlike molecular structure

Answer 20

Bifunctional

Question 21

number of bonds that a given monomer can form

Answer 21

Functionality

Question 22

Molecular weight of is often express as

Answer 22

Number average
Weight average

Question 23

obtained by dividing the chains into a series of size ranges and then determining the number fraction of chains within each size range

Answer 23

Number - average molecular weight

Question 24

based on the weight fraction of molecules within the various size ranges

Answer 24

Weight - average molecular weight

Question 25

alternate way of expressing average chain size of a polymer

Answer 25

Degree of polymerization

Question 26

Single chain bonds are capable of rotating and bending in three dimensions

Answer 26

True

Question 27

occur when the chains assume twisted, coiled, and kinked shapes or contours as a consequence of chain bond rotations

Answer 27

Molecular entanglements

Question 28

Rotational flexibility is independent on repeat unit structure and chemistry

Answer 28

False (dependent)

Question 29

introduction of a bulky or large side group of atoms restricts rotational movement

Answer 29

True

Question 30

those in which the repeat units are joined together end to end in single chains

Answer 30

Linear polymers

Question 31

Polymers may be synthesized in which side-branch chains are connected to the main ones

Answer 31

Branched polymers

Question 32

adjacent linear chains are joined one to another at various positions by covalent bonds

Answer 32

Crosslinked chain

Question 33

Multifunctional monomers forming three or more active covalent bonds make three-dimensional networks

Answer 33

Network polymers

Question 34

situation in which atoms are linked together in the same order (head-to-tail) but differ in their spatial arrangement

Answer 34

Stereoisomerism

Question 35

all of the R groups are situated on the same side of the chain

Answer 35

Isotactic configuration

Question 36

R groups alternate sides of the chain

Answer 36

Syndiotactic configuration

Question 37

random positioning of R group

Answer 37

Atactic configuration

Question 38

chain configurations, or geometrical isomers, are not possible within repeat units having a double bond between chain carbon atoms

Answer 38

False (possible)

Question 39

Trans-polyisoprene, sometimes called ____________, has properties that are distinctly different from natural rubber as a result of this configurational alteration

Answer 39

gutta percha

Question 40

soften when heated (and eventually liquefy) and harden when cooled

Answer 40

Thermoplastics

Question 41

results when a molten thermoplastic polymer is raised to too high a temperature

Answer 41

Irreversible degradation

Question 42

are generally harder and stronger than thermoplastics and have better dimensional stability

Answer 42

Thermoset

Question 43

two different units are randomly dispersed along the chain

Answer 43

Random copolymer

Question 44

two repeat units alternate chain positions

Answer 44

Alternating copolymer

Question 45

identical repeat units are clustered in blocks along the chain

Answer 45

Block copolymer

Question 46

homopolymer side branches of one type may be grafted to homopolymer main chains that are composed of a different repeat unit

Answer 46

Graft copolymer

Question 47

common random copolymer from which automobile tires are made

Answer 47

Styrene - butadiene rubber

Question 48

composed of acrylonitrile and butadiene

Answer 48

Nitrile rubber

Question 49

block copolymer that consists of alternating blocks of styrene and butadiene

Answer 49

Impact - modified polystyrene

Question 50

packing of molecular chains to produce an ordered atomic array

Answer 50

Polymer crystallinity

Question 51

Folds occuring at the faces

Answer 51

Chain-folded model

Question 52

grow to be roughly spherical in shape

Answer 52

Spherulite

Question 53

considered to be the polymer analogue of grains in polycrystalline metals and ceramics

Answer 53

Spherulite

Question 54

expressed using a modified form of Fick’s first law

Answer 54

Permeation flow rate