User:Moira M. Esson/Notebook/CHEM-581/2012/09/07

Objectives

• Crosslink PVOH films through dehydration.
• Prepare more PVOH (MW 130,000) films using HCl, H_{3<sub/>PO4,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

Note:Complete dissolution of the PVOH required a longer amount of stirring(~2hours) and the addition of more deionized H_{2<sub/>O. To prompt complete dissolution, solutions were transferred to larger beakers(~50mL) with larger amounts of H2<sub/>O.}

Crosslinking PVOH Films

Standard Protocol for Crosslinking of films:

1. Weigh out ~0.2 grams of film
2. Place measured film in round metal tray
3. Place tray in oven at ~120 degrees C for 90 minutes

Crosslinked PVOH Films:

1. PVOH(MW 22,000) with 15 wt% maleic acid
2. PVOH (MW 22,000) with 15 wt% succinic acid

Solubility of PVOH Films

General Protocol:

1. Place ~0.1g of film to be tested in a 100mL beaker.
2. Add a stir bar to the beaker
3. Place plastic mesh above the film and stir bar
4. Using a plastic pipette(s) to hold down the plastic mesh, add ~75mL of deionized H_{2<sub/>O to the beaker.}
5. Allow the film to completely dissolve

• • Gently stir the solution only with the stir plate. DO NOT add heat

1. Once the film is completely dissolved, test the viscosity of the solution three times

Viscosity of uncrosslinked PVOH(MW 22,000) 15wt% maleic acid

• Average time:250.28 s

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

1. 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

1. 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.