User:Elizabeth Ghias/Notebook/Experimental Chemistry/2012/08/31

Experimental Chemistry

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Objective To create crosslinked films through acid catalyzed dehydration and to perform viscosity tests. Description Film Preparation with Acid Dehydration All films were prepared using PVA with a MW of 22,000 Film 1 - 0.5110 g PVA in 3 mL water, no acid was added Film 2 - 0.5053 g PVA in 3 mL water, 2 drops of phosphoric acid was added Film 3 - 0.5078 g PVA in 3 mL water, 2 drops of 12 M hydrochloric acid was added Film 4 - 1.0084 g PVA in 6 mL water, no acid was added Film 5 - 1.0010 g PVA in 6 mL water, 3 drops of phosphoric acid was added Film 6 - 1.0044 g PVA in 6 mL water, 3 drops of 12 M hydrochloric acid was added Viscosity Tests (Part 1) The viscosity of the MW = 130,000 PVA and the MW = 22,000 PVA were measured. MW = 130,000 PVA Solution Preparation % wt/mL Calculated g/mL Mass Used Total Volume 2% wt/mL 0.02 g/mL 0.406 g 20 mL 1% wt/mL 0.01 g/mL 0.204 g 20 mL 0.5% wt/mL 0.005 g/mL 0.101 g 20 mL 0.2% wt/mL 0.002 g/mL 0.041 g 20 mL Approximately 10 mL of the first solution tested was poured into the viscometer. The time it took for the sample to travel between the two lines marked on the viscometer were recorded. The test was repeated 2 or 3 times for each sample After the first solution was removed, 10 mL of the next solution was added to the viscometer to rinse out the previous solution. Steps 1 - 4 were repeated for all of the remaining solutions. Data Viscosity Test Results (Part 1) % wt/mL Time 1 Time 2 Time 3 Average Time 2% wt/mL 9.35s 9.48 s 9.51 9.45 s 1% wt/mL 6.46 s 6.16 s n/a 6.31 s 0.5% wt/mL 4.42 s 4.47 s n/a 4.445 s 0.2% wt/mL 4.09 s 4.11 s n/a 4.10 s Notes This area is for any observations or conclusions that you would like to note. Use categories like tags. Change the "Course" category to the one corresponding to your course. The "Miscellaneous" tag can be used for particular experiments, as instructed by your professor. Please be sure to change or delete this tag as required so that the categories remain well organized.