Investigating the Effectivness of Pva and Pvac as Base Polymers in the Production of a Polymer Ball

Investigating the effectivness of PVA and PVAc as base polymers In the production of a polymer ball.

Introduction

A monomer refers to a specific group of atoms that from a molecular unit. When monomers are strung together like a long chain they form polymers. A good analogy of polymers, would be long connections of chains which become tangled like a bunch of spaghetti in a pot. The reason for experimenting with, and understanding polymers is because they play such a major roll and are found in many other molecules that make up life. Important facts about polymers are they have the highest molecular weight amongst molecules, and may consist of millions of atoms. Human DNA is a polymer consisting of over 20 billion component atoms, and they are regarded as the largest and most diverse category of known molecules. The objective was to ultimately understand how different kinds of polymer substances interact with each other, and the specific amounts needed to produce a bouncing ball. Although bouncing balls are made of all types of polymers, we wanted to test to see if it could be made out of these specific solutions. We mixed and omitted combinations of PVA, PVAc, Borax( which is responsible for crosslinking) and cornstarch, in order to try and create a bouncing ball that is non-toxic, eco-friendly and comprised of polymers. The overall outcome or goal in this experiment, was to evaluate which chemical combinations yielded the best attempts at producing a polymer ball that bounced and why.

Figure 1: Schematic illustration of how a polymer is formed. Second illustration is polymer found in white glue.

Methods

PVA and Borax mixture.

The experiment was performed in the chemistry lab at the University of South Florida. The beakers were labeled so that there was no confusion. One PVAc solution, and the other PVA. We wanted to be extra careful when we used Borax and PVAc as both solutions were clear which if weren't labeled would be very difficult to tell apart. We measured 10 mL of Borax in our Graduated cylinder, and poured the measured amount into the 100 mL beaker. We chose to add the borax first and the PVA second. We then repeated the same process with the PVA, measured 10 mL in a graduated cylinder and poured that into the 100ml beaker. We noted that if two graduated cylinders were not available, we would have had to rinse the one that was used thoroughly if not a chemical reaction would start to take place if any residual was left in the cylinder. Once the mixture was in the 100ml beaker we did not stir, the mixture was allowed to sit for 20-30 seconds and allow the chemical reaction or polymerization to begin to take place. After letting it sit, we started to stir until the substance became uniform, we also took our stirrer and poked at the uniformed substance to try and puncture any pockets of substance that may have not had a chance to react. Once the substance was uniformed or a semi solid, it was removed from the leftover solution, put in the palm of our hand and started to be rolled around until it started to form a ball. We first thought it seemed a little messy when we started to roll it around in our hands, but realized it was normal, and just continued rolling. As the ball became more solid it removed any excess residue that was left on our hands when we first started. We continued rolling until the ball was no longer sticky to the touch.

Results

The previous experiment was done to show if PVA, Borax, PVAc and cornstarch when combined in specific ways could in fact produce a polymer ball that bounced. So we conducted multiple experiments with multiple combinations with varying results. With most of the combinations we were able to achieve some form of a polymer ball, with the reactions ranging from one extreme to the other. Some combinations were either to goopy or so firm that in either case the ability to hold shape and bounce was void. Eight test were conducted using our final sample which was the mixture of 10ml of PVA and 10ml of Borax as the best sample. We ran two tests each at Room temperature, two test 0o C, two tests at 50o C, and two tests at 100o C. The two tests we ran at each temperature were how high the ball bounced starting at 100 cm, and how many times the ball bounced above 10 cm starting at a height of 100 cm. For the room temperature ball we concluded that its peak height was 42 cm after dropping it from 100 cm and it bounced a total of 3 times above 10 cm. For the ball at 0* C the same results were found. When we measured the ball at 50o C the ball bounced at a peak height of 22 cm and only bounced one time over 10 cm. When we measured the ball at 100 o C the conclusions deviated from the first two temperatures. The ball at 100o C bounced to a peak height of 15 cm and only bounced one time above 10 cm.

a. We also tested the physical properties of the ball at numerous temperatures. The ball stayed at a consistent spherical shape at 0o C and at room temperature. The ball started