Making Polymers/Renewable Block Copolymers

monomer

a small molecule.

polymer

long-chain molecule made up of repeated pattern of monomers

types of polymerization

Condensation, chain addition, and cross link

condensation polymerization

two monomers react to form a larger unit while a small molecule (water or HCl) is eliminated

chain addition

- involves a vinyl-type monomer

- products of it have simple hydrocarbon backbones

- empirical formula of product is identical to its monomer

initiation

an initiator forms a reactive species(radicals)

propagation

radicals react with monomer to begin chain addition process

stages of chain addition

Initiation, propagation, and termination

termination

When two individual chains react together in which no new radical is made

monomers and initiator amounts

- Increasing amount of monomers = longer chains - Increasing amount of initiator = more, but shorter chains

Homopolymer

has the same monomer unit making up the polymer chain

block copolymer

has two different monomer units that alternation and make up the polymer chain

lactones

undergo transesterification polymerization

annealing

melts the polymer and removes excess solvent

repeat units (n)

(mol monomer)/(mol initiator)

theoretical molecular mass (Mn)

(MW initiator) +(n*MW monomer)

end groups of the homopolymers

Act as initiators for the polymerization of a second monomer

thermoplastics

can be molded by heating about the melting temp. of the hard poly(L-lactide blocks)