Polymer Synthesis

AIM

The major objective of this experiment is to synthesis polymers such as Nylon 66, agar and slime polymer from organic compounds. Moreover, the relationship between polymer structure and polymer morphology is well examined.

PRE-LAB QUESTIONS

Q.1. Nylon 66 is a step growth polymerization. Polymerization is a process of reacting monomer molecules together in a chemical reaction to form three-dimensional networks of polymer chains. There are two general types of polymerization reactions, both with many variations. These are Addition polymerization which occurs when reactive monomers unite without forming any other products, and Condensation polymerization which occurs by condensation of reactive monomers with the elimination of a simple molecule such as water.

Q.2.

-[CH2-CH]-

|

OH

Repeating unit in Polyvinyl Alcohol (PVA)

Q.3. Cross-links are covalent bonds formed between polymer chains, either within or across polymer chains. It is usually either between different chains or between different parts of the same chain. A solution of polyvinyl alcohol (PVA) can be made into a slime by adding borax solution, which creates crosslinks between polymer chains. The borate ion can make weak bonds with the OH groups in the polymer chains so it can link the chains together as shown below. This is called cross-linking.

Q.4. Biopolymers are polymers produced by living organisms. Since they are polymers, biopolymers contain monomeric units that are covalently bonded to form larger structures. Cellulose is a good example of a biopolymer. Beta glucose is the monomer unit in cellulose. As a result of the bond angles in the beta acetal linkage, cellulose is mostly a linear chain.

RESULTS

Table 1:

Polymer Type Observations

Color Physical Properties Elasticity Transparency Adhesion Tensile Strength

* Wet

Nylon

* Dry Nylon

* 4% Agrose gel

* Gooey slime White

White

Colorless

Pink Solid

Solid

Solid

Semi-Solid Elastic

Non-Elastic

Non-Elastic

(brittle)

Moderately Elastic Opaque

Opaque

Transparent

Opaque Smooth

Smooth

Smooth

...