Polymers Flashcards
(20 cards)
What are the repeating units of addition polymers?
Alkenes
What are the two types of polyethylene?
LDPE and HDPE
What are the properties of LDPE?
Highly branched, flexible and transparent, used in sandwich bags
What are the properties of HDPE?
Straight chain, packs well, stronger, more rigid, less transparent, used in milk containers
What are the two isomers of polyisoprene?
trans-polyisoprene (gold ball) and cis-polyisoprene (natural rubber)
What is vulcanization?
Cross-linking natural rubber (cis-polyisoprene) with sulfer to produce tire rubber
What is the repeating unit of PVC?
CH2=CHCl
What is the repeating unit of teflon?
CF2=CF2
What is the repeating unit of polystyrene?
Styrene or ethyl acrylate
What is the repeating unit of PMMA?
Methyl methacrylate found in plexiglass
What are the three classes of condensation polymers covered in class?
Polyesters, polyamides, and polycarbonates
What is another name for polyamides?
Nylons
How is a polyester formed?
Dialcohol + dicarboxylic acid = polyester + n moles of water
How is a polyamide formed?
Dicarboxylic acid + diamine = polyamide + n moles of water
How are nylons named?
Nylon-a,b where a is the number of carbon atoms in the diamine and b is the number of carbon atoms in the diacid
What are some common polyamides?
Nylon-6,6 and Kevlar
What is a common polyester?
Polyethylene terephthalate
What is Lexan and how is it formed?
A polycarbonate formed by the rxn between the disodium salt of bisphenol A and phosgene
How do you calculate the molar mass of a polymer?
nMo
What is the glass transition temperature?
The temperature at which a polymer becomes soft and flexible before melting
