User:Moira M. Esson/Notebook/CHEM-581/2012/09/07: Difference between revisions
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'''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. | '''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== | ==Crosslinking PVOH Films== | ||
Standard Protocol for Crosslinking of films: | Standard Protocol for Crosslinking of films: | ||
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#Place ~0.1g of film to be tested in a 100mL beaker. | #Place ~0.1g of film to be tested in a 100mL beaker. | ||
#Add a stir bar to the beaker | #Add a stir bar to the beaker | ||
#Place plastic | #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. | #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 | #Allow the film to completely dissolve | ||
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DSC will be used to determine the different thermal transitions of the various films | DSC will be used to determine the different thermal transitions of the various films | ||
'''General Protocol for DSC:''' | '''General Protocol for DSC:''' | ||
#Weigh out the mass of a Tzero pan+Tzero lid(Record this measurement) | # 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. | * About 3 mg ± 20% PVOH film was placed in a DSC pan. | ||
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** Pan mass: 51.02 g | ** Pan mass: 51.02 g | ||
** Sample mass: 3.15 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== | ==Notes== | ||
Revision as of 15:59, 22 October 2012
 Project name
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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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