OBJECTIVES
- Label and remove previous PVOH films from Teflon dishes
- Prepare more PVOH (MW 22K) films w/ liquid acid deviations (L - HCl and H3PO4) for film analysis: IR, DSC, solubility, crosslinking, acid catalyzed dehydration, film comparison, etc.
Deviated Acidic PVOH Film Preparations
Prepared PVOH films in water:
- In 10mL beaker, weigh out ~ 0.5 grams PVOH (MW 22K)
(Actual mass = 0.5163g)
- Then, using a graduated cylinder add ~ 3mL H2O to the beaker
- Next, at the fume hood add two drops of hydrochloric acid (HCl) to beaker solution
- In another 10mL beaker, weigh out ~ 1 gram PVOH (MW 22K)
(Actual mass = 1.0204g)
- Next, at the fume hood add two drops of sulfuric acid (H2SO4) to beaker solution
- Then, using a graduated cylinder add ~ 6mL H2O to the beaker
- Finally, in another 10mL beaker, weigh out another ~ 1 gram sample PVOH (MW 22K)
(Actual mass = 1.0040g)
- Then, using a graduated cylinder add ~ 6mL H2O to the beaker
- Next, at the fume hood add two drops of phosphoric acid (H3PO4) to beaker solution
Standard PVOH Film Protocol:
- After adding and combining PVOH (MW 22K) in small beakers with H2O and acids, add stir bars and prepare to stir solutions.
- On hot plate, stir and heat all beaker solutions at 70-80°C for ~ 12 min or until PVOH dissolves.
- Once PVOH solids dissolve in solution, pour each solution in Teflon dishes to sit, cool, and dry in a fume hood for ~ 4 days.
Notes
- An additional 2-3 mL H2O was added to each solution to aid the dissolving of the PVOH
- Heat was reduced when solutions began to boil too rapidly
- As solutions heated, beakers containing the strong acids (HCl and H2SO4) left burn marks at the bottom of solution -- slightly tinting the PVOH 1 gram solutions brown
- While transferring solutions to Teflon dishes, loss of sample within the small beakers (sample loss = incomplete sample transfer)
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PVOH Research
