Polymers Flashcards
macromolecules
high molecular weight org compounds having colloidal size
Polymerization
process of combination of 2 or more monomer units of the same or diff types with or without the elimination of smaller units to form a high molecular weight compound
functionality
no. of bonding sites in a monomer
2 mechanisms of polymerisation
addition
condensation
degree of polymerisation
no. of repeating units in a chain of polymer
homopolymers
consist of 1 kind of repeating unit throughout the whole backbone strand
copolymer
consist of more than one type of repeating monomer units
3 types of linear polymer
1) isotactic: side group monomers are all on the same side of the chain
2) syndiotactic: side grp monomers are alternate on diff sides of the chain
3) atactic: positioned randomly on one side or other
polymer architecture
linear
branched
cross linked
network
Acrylonitrile butadiene styrene copolymer
graft copolymer, consist of 3 monomer systems, that can be tailored to yield a good balance of props
properties of ABS
1) hard, tough, rigid, resistant to stretch and impact
2) excellent heat and chem resistance
3) flammable with high smoke generation
applns of ABS
automative parts, building parts, housewares etc
kevlar
registered trademark name of aromatic polyamide synthetic fiber
properties of kevlar
1) 5 times stronger than steel
2) extremely light weight
3) very high chem R
4) doesnt corrode and it absorbs vibrn easily
5) very high tensile strength
6) high structural rigidity
7) flame resistant, self extinguishable
8) maintains strength and resilience down to cryogenic temps
application of kevlar
1) industrial equip
2) military equipment
3) sports equip
4) personal safety equipment
