User:Karlena L. Brown/Notebook/PVOH Research/2012/09/02

From OpenWetWare

Jump to: navigation, search
PVOH Research Main project page
Previous entry      Next entry

OBJECTIVES

  1. Label and remove previous PVOH films from Teflon dishes
  2. Prepare more PVOH (MW 22K) films with both solid and liquid acid deviations (S - Maleic and Succinic; L - HCl and H3PO4) for film analysis: IR, DSC, solubility, crosslinking, acid catalyzed dehydration, film comparison, etc.
  3. Determine ratios and percentages in which solid acids will be added to the PVOH (MW 22K)

Deviated Acidic PVOH Film Preparations 3

Deviated HCl PVOH films prepared in water:

  • In 10mL beaker, weigh out ~ 0.5 grams PVOH (MW 22K)

(Actual mass = 0.5181g)

  • 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
  • Afterwards, calculate and weigh out a ~10%wt equivalent of maleic acid
  • Add maleic acid equivalent to the acidic PVOH solution

(Actual Maleic Acid mass = 0.0582g)

  • Repeat this procedure again; however use succinic acid as substitute for maleic acid.

(Actual PVOH mass = 0.5163g) (Actual Succinic Acid mass = 0.0571g)


Deviated H3PO4 PVOH films prepared in water:

  • In another 10mL beaker, weigh out ~ 1 gram PVOH (MW 22K)

(Actual mass = 1.0054g)

  • 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
  • Afterwards, calculate and weigh out a ~15%wt equivalent of maleic acid
  • Add maleic acid equivalent to the acidic PVOH solution

(Actual Maleic Acid mass = 0.1565g)

  • Repeat this procedure again; however use succinic acid as substitute for maleic acid.

(Actual PVOH mass = 1.0125g) (Actual Succinic Acid mass = 0.1519g)


Standard PVOH Film Protocol:

  • After adding and combining PVOH (MW 22K) in small beakers with H2O and all acids (HCl, H3PO4, maleic and succinic), 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 all solids dissolve.
  • Once PVOH and acidic solids dissolve in solution, pour each solution in Teflon dishes to sit, cool, and dry in a fume hood for ~ 2 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) left burn marks at the bottom of solution -- slightly tinting the PVOH solutions brown
  • While transferring solutions to Teflon dishes, loss of sample within the small beakers (sample loss = incomplete sample transfer)
  • PVOH (MW 22K) films w/just liquid acids were harder and more rigid than PVOH (MW 22K) films w/ both liquid and solid acids added.


Personal tools