Journal of Polymer and Biopolymer Physics Chemistry
ISSN (Print): 2373-3403 ISSN (Online): 2373-3411 Website: https://www.sciepub.com/journal/jpbpc Editor-in-chief: Martin Alberto Masuelli
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Journal of Polymer and Biopolymer Physics Chemistry. 2023, 11(1), 1-10
DOI: 10.12691/jpbpc-11-1-1
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Establishment of the Flory-Fox Equation for Polymethyl Methacrylate (PMMA) Using Differential Scanning Calorimetry (DSC) and Determination of Tacticity Using Quantitative Proton Nuclear Magnetic Resonance Spectroscopy (qHNMR)

Ronald P. D’Amelia1, and Evan H. Kreth1

1Chemistry Department, Hofstra University, Hempstead, NY, USA

Pub. Date: July 11, 2023

Cite this paper:
Ronald P. D’Amelia and Evan H. Kreth. Establishment of the Flory-Fox Equation for Polymethyl Methacrylate (PMMA) Using Differential Scanning Calorimetry (DSC) and Determination of Tacticity Using Quantitative Proton Nuclear Magnetic Resonance Spectroscopy (qHNMR). Journal of Polymer and Biopolymer Physics Chemistry. 2023; 11(1):1-10. doi: 10.12691/jpbpc-11-1-1

Abstract

Glass transition temperature (Tg), termed the “melting point of amorphous materials” is the temperature at which an amorphous material changes from a hard, glassy state to a soft, rubbery one. As the number average molecular weight (Mn) of the amorphous material increases, its glass transition temperature also increases, but ultimately levels off at a maximum value labeled Tg. Differential scanning calorimetry (DSC) was utilized to evaluate Tg for seventeen samples of polymethyl methacrylate (PMMA) whose Mn values ranged from three thousand to one and a half million. These values were then plotted against reciprocal Mn, producing a Flory-Fox equation of Tg = 135°C – 1.4 x 105 °Cᐧgᐧmol-1/Mn, with a correlation coefficient of 0.98. The Tg of binary mixtures of PMMA of different Mn values were also examined in this experiment. Tg values were calculated using the Fox equation: 1/Tg = w1/Tg1 + w2/Tg2 where w represents the weight percent of each PMMA sample. Correlation coefficients of 0.96 and 0.97 were achieved for the graphs plotting Tg against weight percent of the lower Mn value PMMA. Lastly, quantitative proton nuclear magnetic resonance spectroscopy (qHNMR) was utilized to determine the relative tacticity of binary mixtures of isotactic and syndiotactic PMMA. It was determined that the peak integrations for the methylene or methyl hydrogens, at their respective chemical shifts for each PMMA, could be used to determine relative tacticity. These experiments demonstrate the quantitative applications of DSC and NMR, as well as their suitability within the undergraduate chemistry laboratory.

Keywords:
Polymethyl Methacrylate (PMMA) Flory-Fox equation glass transition temperature (Tg) differential scanning calorimetry (DSC) tacticity quantitative proton nuclear magnetic resonance spectroscopy (qHNMR)

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References:

[1]  Wikipedia, “Polymethyl Methacrylate,” June 20, 2023. [Online]. https://en.wikipedia.org/wiki/Poly(methyl_methacrylate) [Accessed June 26, 2023].
 
[2]  Team Xometry, “Everything You Need To Know About Acrylic (PMMA)” May 4, 2022. [Online]. https://www.xometry.com/resources/materials/acrylic-pmma/ [Accessed June 26, 2023].
 
[3]  Shawn Wasserman. “What is PMMA and How is It Used in the Medical World?” September 25, 2019. [Online]. https://www.ansys.com/blog/what-is-pmma-how-it-is-used-healthcare [Accessed June 26, 2023].
 
[4]  The Editors of Encyclopedia Britannica, “Polymethyl methacrylate” May 25, 2023 [Online]. https://www.britannica.com/science/polymethyl-methacrylate [Accessed June 26, 2023].
 
[5]  Ali, U., Juhanni Bt., K., Karim, A., Buang, N.A. “A Review of the Properties and Applications of Poly (Methyl Methacrylates) (PMMA)” Polymer Review, 55:4, 678 – 705 (2015).
 
[6]  Forte, M.A., Silva, R.M., Tavares, C. J., Silva, R.F. “Is Poly (Methyl Methacrylate) (PMMA) a Suitable Substrate for ADL?: A Review” Polymers, 13, 1346 – 1374, (2021).
 
[7]  Duval-Terrie, C., Lebrun, L. “Polymerization and Characterization of PMMA” J. Chemical Ed. 83, #3, 443-446 (2006).
 
[8]  Wikipedia, “Differential scanning calorimetry,” May 19, 2023. [Online]. https://en.wikipedia.org/wiki/Differential_scanning_calorimetry [Accessed June 26, 2023].
 
[9]  Blanchard, L.P. Hesse, J. Malhotra, S.L. “Effect of Molecular Weight on Glass Transition by Differential Scanning Calorimetry” Can. J. Chem, 52, 3170-3175 (1974).
 
[10]  D’Amelia, R. P., Khanyan, B., “An Experimental Review: Evaluation of the Flory-Fox Equation for the Relationship of Glass Transition Temperature (Tg) vs Molar Mass of Polystyrene Using Differential Scanning Calorimetry (DSC),” Journal of Polymer and Biopolymer Physics Chemistry, 10(1), 10-17, August 2022.
 
[11]  Collins, E.A., Bares, J., Billmeyer, F.W., Experiments in Polymer Science, Wiley-Interscience, New York 1973.
 
[12]  Sperling, L. H., Introduction to Physical polymer Science, 4th edition Wiley-Interscience, Hoboken, New Jersey, 2006.
 
[13]  Alger, M., S. M. Polymer Science Dictionary, Elsevier Applied Science, New York, New York, 1989
 
[14]  Rabek, J. F., Experimental Methods in Polymer Chemistry – Principles and Applications, Wiley-Interscience, New York, New York, 1980.
 
[15]  Elias, H-G., Macromolecules Vol 1, Structure and Properties, Volume 2, _ Synthesis and Materials, Plenum, New York, New York, 1977.
 
[16]  Flory, P.J. Principles of Polymer Chemistry” Cornell Press Ithaca, New York, 1953
 
[17]  Mark, J. E., Eisenberg, A., Graessley,W.W , Mandelkern, L., Samulski, E.T., Koenig, J.L. and Wignall, G.D., Physical Properties of Polymers, 2nd ed. American Chemical Society, Washington, DC, 1993.
 
[18]  Abiad, M.G., Carvajal, M.T., Campanella, O.H. “A Review on Methods & Theories to Describe the Glass Transition Phenomenon: Applications in Food & Pharmaceutical Products,” Food Eng. Res. 1, 105-132, (2009)
 
[19]  Fox, T.G., & Flory, P.J.” Second Order Transition Temperatures and Related Properties of Polystyrene I Influence of Molecular Weight” J. Applied Phys. 21 (6), 581-591 (1950).
 
[20]  Fox, T.G., & Flory, P.J. “The Glass Temperature and Related Properties of Polystyrenes Influence of Molecular Weight” J. Polymer Sci, 14, 315-319, (1954).
 
[21]  Fox, T.G. & Loshaek, S. “Influence of Molecular Weight and Degree of Crosslinking on the Specific Volume and Glass Temperature of Polymers” J. Polym. Sci., 15, 371- 390 (1955)
 
[22]  Williams, M.L., Landel, R.F., & Ferry, J.D.: “The Temperature Dependence of Relaxation Mechanism in Amorphous Polymers and Other Glass Forming Liquids”, J. Am. Chem. Soc. 77, 3701-3707 (1955).
 
[23]  Hirai, N. Eyring, H. “Bulk Viscosity of Polymer Systems” J. Polymer Sci. 37, 51-70, (1959).
 
[24]  Gibbs, J.H. & DiMarzio, E.A. “Nature of the Glass Transition and The Glass State” J. Chem Phys, 28, 373-383 (1958).
 
[25]  Gibbs, J.H.” Nature of the Glass Transition in Polymers” J. Chem. Phys. 25, 185-185 (1956).
 
[26]  Beevers, R. B. White, E.F.T., “Dependence of the Glass Transition Temperature of PMMA on Molecular Weight” Trans. Faraday Soc., 56, 744-752 (1960)
 
[27]  Dudek, T. J.; Lohr, J. J. “Glass Transition Temperature of PMMA Plasticized with Low Concentrations of Monomer and Diethyl Phthalate” J. of Applied Polymer Sci. 9, 12, 3795-3818, (1965)
 
[28]  Kabomo, M.T.; Blum, F.D. “Glass Transition Behavior of PMMA Thin Films” Polymer Preprints, American Chemical Society, (Jan 2001).
 
[29]  Kabomo, M. T.; “Glass Transition Behavior of Thin Poly (methyl methacrylate) Films on Silica”, Masters Theses 2151 (2002).
 
[30]  Roth, C.B.; Pound, A.; Kamp, S.W.; Murray, C.A.; Dutcher, J.R. “Molecular-Weight Dependence of the Glass Transition of Freely-Standing PMMA Films”, Eur. Phys J.E. 20, 441-448 (2006).
 
[31]  Mohammadi, M.; Fazli, H., Karevan, M.m Davoodi, J, “The Glass Transition Temperature of PMMA: A Molecular Dynamics Study and Comparison of Various Determination Methods” European Polymer Journal, 91, 121-133, (2017).
 
[32]  Zhang, L, Torkelson, J.M. “Emhanced Glass Transition Temperature of Low Molecular Weight PMMA by Initiator Fragments Located at Chain ends” Polymer 122 194-199 (2017)
 
[33]  Startsev, O.V., Lebedev, M.P. “Glass Transition Temperature and Characteristic Temperatures of α Transition in Amorphous Polymers Using the Example of PMMA” Polymer Science, Series A 60, 911-923 (2018).
 
[34]  Wikipedia, “Tacticity,” June 26, 2023. [Online]. https://en.wikipedia.org/wiki/Tacticity [Accessed June 26, 2023].
 
[35]  Bovey, F.A. “Configurational Sequence Studies by NMR and the Mechanism of Vinyl Polymerization” Pure and Applied Chem. 15 (3-4), 349 – 368 (1967)
 
[36]  Jenkins, A.D., Kratochvil, P., Stepto, R.F.T., Suter, U.W. “Glossary of Basic Terms in Polymer Science (IUPAC Recommendations)”, Pure Appl. Chem., 68, Issue 12, 2287 – 2311 (1996)
 
[37]  Jenkins, A.D. “Stereochemical Definitions & Notations Relating to Polymers”, Pure Appl. Chem. 53, 733, (1981)
 
[38]  Woo, E.M.; Chang, L. “Tacticity in Vinyl Polymers” Encyclopedia of Polymer Science and Technology (2011)
 
[39]  Thompson, E.V. “Dependence of the Glass Transition Temperature of PMMA on Tacticity and Molecular Weight” J. Polymer Science – Part A-2, 4, 199 – 208 (1966)
 
[40]  Chang, L.,; Woo, E.M. “ Tacticity Effects on Glass Transition and Phase Behavior in Binary Blends of PMMA of Three Different Configuration” Polymer Chem. 1, 198-202 (2010)
 
[41]  Chat, K., Tu, W,; Unni, A.B.; Adrjanowicz, K. “ Influence of Tacticity of the Glass Transition Dynamic of PMMA under Elevated Pressure and Geometrical Nanoconfirement” Macromolecules 54, 18, 8526 – 8537 (2021)
 
[42]  Schilling, F.C.; Bovey, F.A.; Bruch, M.D.; Kozlowski, S. “Observations of the Stereochemical Configuration of PMMA by Proton Two-Dimensional J- Correlated and NOE-Correlated NMR Spectroscopy” Macromolecules 18, 7, 1418 (1985)
 
[43]  Ober, C.K. “Polymer Tacticity in Simulated NMR Spectra” J. Chemical Ed. 66, #8, 645-647. (1989)
 
[44]  Goni, I.; Gurruchaga, M.; Valero, M.; Guzman, G.M. “Determination of the Tacticity of PMMA Obtained from Graft Copolymers” Polymer, 33, #14, 3089 – 3094, (1992).
 
[45]  Fried, J.R., Polymer Science & Technology, Prentice Hall PTR, Upper Saddle River, 2003, 180.