CHEM 4214 Lecture Notes - Lecture 2: Benzyl Group, Repeat Unit, Opata Language
Document Summary
Structural isomerism: identical set of atoms with different structures; different categories of structural isomerism: positional isomerism ex: -> semi-crystalline structure: calling it semi b/c almost never have all transsome part will be amorphous. Tmelt for trans = 65 c for cis, goes through glass transition (when lower t, solidifies, but still amorphous) has rubbery structure, like tires: can open just one of the double bonds. 1 and 4 are the carbons to which we link monomers. Chem4212 polymers page 4 isotactic syndiotactic: random copolymer, alternating copolymer. ---ababababababababababababab---------- these above 2 are not that useful b/c disordered: block copolymers di-block aabb this helps combine material properties of both monomers can also make tri-block: aabbaa, graft block polymer. M = nm0 n = degree of polymerization. M0 = molecular weight of repeat unit e. g. polyethylene n = 10,000. M = n*28 g/mol = 280,000 g/mol end effects are negligible when we have such high degree of polymerization.
