Experiment 17
Polymers
By Kaiyi Hall
3/7/16
Dr. Liskin
Background
Polymers are macromolecules built from smaller molecular subunits, called monomers. Synthetic polymers can be classified into two main types according to the mechanism by which they synthetically grow from monomer to polymer: chain-growth polymers and step-growth polymers. This classification scheme is an update from historical nomenclature, in which polymers were classified by whether there existed a byproduct of the polymerization reaction (condensation polymerization) or not (addition polymerization). In a step-growth reaction, the growing polymer chains (of any molecular length) may react with each other to form longer polymer chains. The monomer or dimer may react in just the same way as a polymer containing hundreds of monomer units. In chain-growth polymerization, however, only monomers may react with growing polymer chains. That is, two growing polymer chains cannot join together as in the case during step-growth polymerization.
Poly(methylmethacrylate) is formed by a process known as addition polymerization (a stepwise addition of monomers to a lengthening chain with no loss of atoms in the process). The functional group that permits one monomer to connect with another is the carbon-carbon double bond, which is the distinguishing feature of the class of organic compounds called alkenes. The name Nylon 6,6 is derived from the fact that both the diamine and diacid used in the reaction donate 6 carbons to the polymer chain during synthesis. The chemical structure of the repeat unit in Nylon 2,2 would be the same, except each diamine and diacid would have 4 less CH2 groups. Aside from that difference, the chemical structures would be the same. In this lab, we will be making an addition polymer, a condensation polymer, changing the characteristics of a polymer by forming crosslinks, and changing the characteristics of a polymer by hydration.
Mechanism
[pic 1]
[pic 2][pic 3][pic 4][pic 5]
Data
Reaction Description
Rxn 1 plexiglass | |
2. Nylon 6,6 | The reaction formed a thin film at first. Final product was white, fragile and paper like. |
3. Sodium Polyacrylate | when gel came in contact with the sodium, it when back to its aqueous state. |
4. crosslinking of a polymer | Upon stirring the product, it turned to slime |
Beaker | 106.54g |
With water | 137.79g |
Calculations
Water / orgional weight
137.79g/106.54g = 1.2933g of water added