Investigating the Ratio Between Poly-Vinyl Alcohol Essay Example for Free

Investigating the Ratio Between Poly-Vinyl Alcohol Essay Introduction: Poly-Vinyl Alcohol (PVA) is a water-soluble synthetic polymer that will be used as one element to form the well know bouncing ball, along with Sodium Borate (borax), which has a variety of uses because of its weak base. PVA is ideal for this experiment because it is odorless, nontoxic, has high tensile strength and flexibility. The binder characteristics of PVA offer excellent adhesion to porous, water-absorbent surfaces. A local manufacturer wants to find a material to create a simple toy: a bouncing ball. Research institutions collaborate with local manufacturers and provide professional assistance with their projects. In trying to create a bouncing ball, one must find the appropriate ratio of the two that forms a solid for which have the properties that a bouncing ball consist. It is important that we find the correct ratio so that it is perfect shape, texture, and saltation. The main property that we are testing for is the products bounciness. Figure 1: The reaction of PVA and borax. In the above illustration, two PVA molecules are shown being cross-linked by a hydrated borax molecule. Four molecules of water are also produced. Hypothesis: In this experiment, I predict that if more Poly-vinyl Alcohol over Sodium Borate, then the appropriate bouncing solid will be formed. Methods: With the supplied solutions of PVA and sodium borate, my group and I took 100 mL of each solution. We measured out different ratios repeatedly to find the appropriate ratio. Start with a happy medium of 10mL (PVA) and 20mL (Sodium Borate) and examined the results. The results are not accurate so you have to test the extremes and then examine which way to continue. In my experiment, more of PVA is needed and less of sodium borate is needed. Continue testing until you get closer and closer to an adequate ratio with a good solid product, which we can to the conclusion that 4:1 as well 7:1 worked as good ratios to further test. We tested the ratio by cooling one and heating the other. By cooling the product it was able to harden and somewhat stay in shape. On the other hand, by heating it it doesn’t keep its form thus unable to be bounced. So to harden the heated product follow the theory of heating (50Â °c) to then immediately cooling (12Â °c) the product; this helps to harden the product inside out thus allow the product to keep its shape as well as bounce like a true manufactured bouncy ball. Results: Ratios – table 1 Trial(s)| Amount of PVA| Amount of Sodium Borate| Ratio| Description| 1| 10 mL| 20 mL| 1:2| slimy| 2| 3 mL| 30 mL| 1:10| watery| 3| 30 mL| 3 mL| 10:1| play-dough| 4| 20 mL| 1 mL| 20:1| foamy| 5| 10 mL| 2 mL| 5:1| rubbery| 6| 8 mL| 2 mL| 4:1| slightly crumbly| -| 12 mL| 3 mL| 4:1**| harder/shaped| 7| 15 mL| 5 mL| 3:1| slimy/not keeping form| 8| 7 mL| 1 mL| 7:1| too slimy| -| 14 mL| 2 mL| 7:1**| harder/shaped| Note: ** multiple tests (heated, cooled, heated and cooled) Bouncing Height – table 2 Ratio| Iced (12Â °c)| Heated (50Â °c)| Heated then Cooled| 4:1| 8-10 cm| -| 30-32 cm| 7:1| 9-11 cm| -| 19-20 cm| pH 8 weakly alkaline Discussion: A local manufacturer wanted my team to find a suitable ratio to create the well-known toy, the bouncing ball. In efforts to do so, our TA supplied PVA, along with sodium borate, to the students. Each group could only acquire so much at a time. My group acquired 100 mL of both PVA and sodium borate. To start, we did a 1:2 ratio just as a test to see if it would solidify into a ball. As a result, it came out slimy so we tried to up the amount of sodium borate (1:10 ratio), which lead us to a more watery product. Since increasing the amount of borax lead us in the wrong direction, we increased PVA and lowered sodium borate to a 10:1 ratio. This ratio gave us a play-dough outcome, which was closer to what we needed. Decreasing the amount of solution to a 5:1 ratio, we moved even closer. The 5:1 was starting to feel rubbery. After seeing how close we were with the 5:1, we tried the 4:1. Our 4:1 and 7:1 were fairly similar and the closet to our projected outcome but it was not quite there yet. So, by heating and cooling each result gave us a somewhat reasonable result. The result of cooling our 7:1 product for 30 minutes was a harder but still lacked shape as well as the 4:1 product that was cooled for 30 minutes. The 7:1 result was able to bounce 9-11 cm in height while the 4:1 product was able to bounce to a similar height of 8-10 cm. Both products heated would not bounce or keep form, so we immediately put both on ice. As most people should know, with the rapid temperature (from hot to cold), it causes an object to harden from the inside out. So, with this theory in mind, after the heated products failed we placed them on ice and let it sit there and harden. The products hardened over a 15-minute time frame and we could clearly see the difference between these and the rest of our trials. The heated then cooled product for the 7:1 ratio could bounce to a height interval of 19-20 cm, while the product from the 4:1 ratio could bounce to a height interval of 30-32 cm. Ultimately, we have to accept the best product for the manufacturer to mass produce and market so that the most money can be made. From the data collected, the ratio 4:1 is the closest to form a perfect product (bouncy ball) simply because it bounced higher which meant it was harder as well as kept its shape. But, from this experiment, we can conclude that either just cooling the ratio or by heating then immediately cooling the ratio product creates an adequate bouncy ball that when dropped it bounces like a true bouncy ball. References: Experiment 2. Polymers:. N.p., n.d. Web. 19 Sept. 2012. http://matse1.matse.illinois.edu/polymers/e.html. Polyvinyl Alcohol. Wikipedia. Wikimedia Foundation, 26 Aug. 2012. Web. 19 Sept. 2012. http://en.wikipedia.org/wiki/Polyvinyl_alcohol. Borax. Wikipedia. Wikimedia Foundation, 18 Sept. 2012. Web. 19 Sept. 2012. http://en.wikipedia.org/wiki/Borax.