User:Moira M. Esson/Notebook/CHEM-581/2012/09/07: Difference between revisions
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== | ==Objectives== | ||
* | * Crosslink PVOH films through dehydration. | ||
*Prepare more PVOH (MW 130,000) films using HCl, H<sub>3<sub/>PO<sub>4,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''' | |||
{| {{table}} | |||
| align="center" style="background:#f0f0f0;"|'''''' | |||
| align="center" style="background:#f0f0f0;"|'''Film #1''' | |||
| align="center" style="background:#f0f0f0;"|'''Film #2''' | |||
| align="center" style="background:#f0f0f0;"|'''Film #3''' | |||
| align="center" style="background:#f0f0f0;"|'''Film #4''' | |||
| align="center" style="background:#f0f0f0;"|'''Film #5''' | |||
| align="center" style="background:#f0f0f0;"|'''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 [H<sub>3<sub/>PO<sub>4 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 H<sub>2<sub/>O. To prompt complete dissolution, solutions were transferred to larger beakers(~50mL) with larger amounts of H<sub>2<sub/>O. | |||
==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 stemless buchner funnel top above the film and stir bar | |||
#Using a plastic pipette(s) to hold down the plastic mesh, add ~75mL of deionized H<sub>2<sub/>O 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 | |||
<br> | |||
Viscosity of uncrosslinked PVOH(MW 22,000) 15wt% maleic acid | |||
{| {{table}} | |||
| align="center" style="background:#f0f0f0;"|'''Trial''' | |||
| align="center" style="background:#f0f0f0;"|'''Time [s]''' | |||
|- | |||
| 1||246.67 | |||
|- | |||
| 2||253.48 | |||
|- | |||
| 3||250.68 | |||
|} | |||
*Average time:250.28 s | |||
==DSC on PVOH Films== | |||
DSC will be used to determine the different thermal transitions of the various films | |||
'''General Protocol for DSC:''' | |||
# Weigh out the mass of a Tzero pan+Tzero lid(Record this measurement) | |||
# Cut and weigh out ~ 280 - 320mg of PVOH film sample to place in the Tzezo pan | |||
# Once each sample is placed in the pan, then place the lid onto the pan | |||
# Use a Tzero press to secure and press the lid tightly over top the sample within the pan | |||
# Open TA instrument explorer on computer. Select instrument to be used(in this case DSC) | |||
# On control button, click event to create a new event | |||
# To create a new event or run, click either the apply or append commands | |||
# To modify a run, go to the experimental command and run a method edit | |||
# Save all changes made to an experimental run in order to analyze samples | |||
<br> | |||
To Collect the information from the DSC: | |||
# Click on export data file command | |||
# Go to file and plot signals command | |||
# Export the information obtained and save it(if possible save on flash drive) | |||
# Go to signals command and select signal section, then time command underneath | |||
# Select the analyze data command, then afterwards the integrate peaks command underneath | |||
# Accept values established by integrating the peaks | |||
# Click the analyze data command again to assign the glass transition value | |||
# Select the area in which the glass transition point is seen and integrate that information | |||
# Accept the values established from the glass transition point | |||
* About 3 mg ± 20% PVOH film was placed in a DSC pan. | |||
* Uncrosslinked PVOH (MW 22000) + 15% maleic acid + H<sub>3</sub>PO<sub>4</sub> | |||
** Pan mass: 49.42 mg | |||
** Sample mass: 3.13 mg | |||
* Uncrosslinked PVOH (MW 22000) + 15% succinic acid + H<sub>3</sub>PO<sub>4</sub> | |||
** Pan mass: 51.02 g | |||
** Sample mass: 3.15 g | |||
* [[Media:PVOH(22K), 15%M, H3PO4.pdf|Graph of heat flow of uncrosslinked PVOH (MW 22000) + 15% maleic acid + H<sub>3</sub>PO<sub>4</sub>]]. | |||
** Two possible glass transitions at 105.79°C and at 155.16°C were observed(able to observe on graph by looking at the change in slope). Running DSC on the sample a second time may clarify which is the true glass transition temperature. | |||
** Two sharp peaks at 144.66°C and at 155.64°C were observed. A reaction may have occurred at these temperatures or a phase change may have occurred | |||
* [[Media:PVOH(22K), H3PO4.pdf|Graph of heat flow of uncrosslinked PVOH (MW 22000) + H<sub>3</sub>PO<sub>4</sub>]]. | |||
** A glass transition was observed at 82.61°C. | |||
** A sharp peak was observed at 179.47°C. This may be caused by a reaction or phase change. | |||
==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 H<sub>3</sub>PO<sub>4 | |||
*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 H<sub>3</sub>PO<sub>4 | |||
*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 H<sub>3</sub>PO<sub>4 | |||
*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 H<sub>3</sub>PO<sub>4 | |||
*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. | |||
Revision as of 15:59, 22 October 2012
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Objectives
PVOH(MW 130,000) Films
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 H2O. To prompt complete dissolution, solutions were transferred to larger beakers(~50mL) with larger amounts of H2O. Crosslinking PVOH FilmsStandard Protocol for Crosslinking of films:
Crosslinked PVOH Films:
Solubility of PVOH FilmsGeneral Protocol:
Viscosity of uncrosslinked PVOH(MW 22,000) 15wt% maleic acid
DSC on PVOH FilmsDSC will be used to determine the different thermal transitions of the various films General Protocol for DSC:
Notes
Observations
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