Objectives
- Crosslink PVOH films through dehydration.
- Prepare more PVOH (MW 130,000) films using HCl, H3PO4,and maleic or succinnic acid
- Run solubility tests of crosslinked and uncrosslinked PVOH films
- Run Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning calorimetry(DSC) on PVOH films
PVOH(MW 130,000) Films
- The standard protocol for PVOH Film preparation was used.
- Note: If indicated that acid was added
Prepared PVOH(MW 130,000) Films
'
|
Film #1
|
Film #2
|
Film #3
|
Film #4
|
Film #5
|
Film #6
|
Mass PVOH used(g) |
1.0855 |
0.9964 |
1.0373 |
1.0106 |
1.0178 |
1.0215
|
Amount of [HCl] added(drop) |
0 |
2 |
0 |
2 |
0 |
2
|
Amount of [H3PO4 added(drop) |
2 |
0 |
2 |
0 |
2 |
0
|
Amount of succinic acid added(g) |
0 |
0 |
0 |
0 |
0.1528 |
0.1021
|
Amount of maleic acid added(g) |
0 |
0 |
0.1556 |
0.1071 |
0 |
0
|
Note:Complete dissolution of the PVOH required a longer amount of stirring(~2hours) and the addition of more deionized H2O. To prompt complete dissolution, solutions were transferred to larger beakers(~50mL) with larger amounts of H2O.
Crosslinking PVOH Films
Standard Protocol for Crosslinking of films:
- Weigh out ~0.2 grams of film
- Place measured film in round metal tray
- Place tray in oven at ~120 degrees C for 90 minutes
Crosslinked PVOH Films:
- PVOH(MW 22,000) with 15 wt% maleic acid
- PVOH (MW 22,000) with 15 wt% succinic acid
Solubility of PVOH Films
General Protocol:
- Place ~0.1g of film to be tested in a 100mL beaker.
- Add a stir bar to the beaker
- Place plastic mesh above the film and stir bar
- Using a plastic pipette(s) to hold down the plastic mesh, add ~75mL of deionized H2O to the beaker.
- Allow the film to completely dissolve
- Gently stir the solution only with the stir plate. DO NOT add heat
- Once the film is completely dissolved, test the viscosity of the solution three times
Viscosity of uncrosslinked PVOH(MW 22,000) 15wt% maleic acid
Trial
|
Time [s]
|
1 |
246.67
|
2 |
253.48
|
3 |
250.68
|
DSC on PVOH Films
DSC will be used to determine the different thermal transitions of the various films
- About 3 mg ± 20% PVOH film was placed in a DSC pan.
- Uncrosslinked PVOH (MW 22000) + 15% maleic acid + H3PO4
- Pan mass: 49.42 mg
- Sample mass: 3.13 mg
- Uncrosslinked PVOH (MW 22000) + 15% succinic acid + H3PO4
- Pan mass: 51.02 g
- Sample mass: 3.15 g
Notes
- For Solubility still need to test:
- PVOH (MW 22,000) uncrosslinked with 15wt% succinnic acid
- PVOH (MW 22,000) uncrosslinked with 10wt% maleic acid
- PVOH (MW 22,000) crosslinked with 15wt% maleic acid
- PVOH (MW 22,000) crosslinked with 15wt% succinnic acid
- PVOH (MW 22,000) uncrosslinked with 10wt% succinnic acid
- PVOH (MW 22,000) uncrosslinked
- PVOH (MW 22,000) crosslinked
- For films need to prepare:
- PVOH (MW 130,000) uncrosslinked with 15wt% maleic acid
- PVOH (MW 130,000) uncrosslinked with 10wt% maleic acid
- PVOH (MW 130,000) crosslinked with 15wt% maleic acid
- PVOH (MW 130,000) crosslinked with 10wt% maleic acid
- PVOH (MW 130,000) uncrosslinked with 15wt% succinic acid
- PVOH (MW 130,000) uncrosslinked with 10wt% succinic acid
- PVOH (MW 130,000) crosslinked with 15wt% succinic acid
- PVOH (MW 130,000) crosslinked with 10wt% succinic acid
- PVOH (MW 130,000) uncrosslinked(and crosslinked) with 15wt% succinic acid and HCl
- PVOH (MW 130,000) uncrosslinked(and crosslinked) with 10wt% succinic acid and H3PO4
- PVOH (MW 130,000) uncrosslinked(and crosslinked) with 15wt% maleic acid and HCl
- PVOH (MW 130,000) uncrosslinked and crosslinked with 10wt% maleic acid and H3PO4
- PVOH (MW 22,000) uncrosslinked and crosslinked with 10wt% maleic acid
- PVOH (MW 22,000) uncrosslinked and crosslinked with 15wt% maleic acid
- PVOH (MW 22,000) uncrosslinked and crosslinked with 10wt% succinic acid
- PVOH (MW 22,000) uncrosslinked and crosslinked with 15wt% succinic acid
- PVOH (MW 22,000) uncrosslinked and crosslinked with 10wt% maleic acid and H3PO4
- PVOH (MW 22,000) uncrosslinked and crosslinked with 15wt% maleic acid and HCl
- PVOH (MW 22,000) uncrosslinked and crosslinked with 10wt% succinic acid and H3PO4
- PVOH (MW 22,000) uncrosslinked and crosslinked with 15wt% succinic acid and HCl
Observations
- Crosslinked PVOH films became more rigid and changed color from transparent to faintly yellow-brown.
- The viscometer used for previous tests was discovered to be cracked. A new viscometer was subsequently used.
PVOH(MW 22,000) Films
Prepared PVOH(MW 22,000) Films
'
|
No acid
|
HCl
|
H3PO4
|
No acid |
1.0115 |
0.5181 |
1.0054
|
10 wt% maleic acid |
|
0.5181 |
|
15 wt% maleic acid |
|
|
1.0054
|
10 wt% succinic acid |
|
0.5163 |
|
15 wt% succinic acid |
|
|
1.0125
|
|