عنوان مقاله [English]
The physical, chemical and mechanical properties of polymer systems depend on the micro-structural characteristics of their macromolecular chains. Along with the most characteristic kinetic parameters in copolymerization reactions are the reactivity ratios, which give a clear idea of the average composition and the monomer sequence distribution in copolymer systems. This research studies the solution radical copolymerization of methacrylic acid (MAA)-ethyl acrylate (EA) system at low conversion with 2,2'-azobisisobutyronitrile (AIBN) as thermal initiator at 60°C in deuterated dimethyl sulfoxide (DMSO-d6) as a reaction solvent. In this case, the monomer reactivity ratios were determined using linear off-line 1H nuclear magnetic resonance spectroscopy (1H NMR) methods such as Mayo-Louis, Finemann-Ross, Inverted Finemann-Ross , Ezrielev-Brokhina-Roskin, Joshi-Joshi, Kelen-Tudos, extended Kelen- Tudos, Mao-Huglin at low and high conversions. The next estimation process in off-line 1H NMR methods were performed by applying techniques based on ordinary least square (OLS) and generalized least square (GLS). The results showed that the GLS approach compared to the OLS increased regression coefficients (R2) and the order of magnitude of parameter variances obtained from GLS was many times lower than that obtained from OLS. In addition, the monomer reactivity ratios obtained by the Mao-Huglin method and the GLS approach showed the best linear estimation.
1. Williams P.A., Handbook of Industrial Water Soluble Polymers, Wiley Online Library, 2007.
2.Erbil C., Özdemir S., and Uyanık N., Determination of the Monomer Reactivity Ratios for Copolymerization of Itaconic Acid and Acrylamide by Conductometric Titration Method, Polymer, 41, 1391-1394, 2000.
3.Kine B. and Novak R., Encyclopedia of Polymer Science and Engineering, Wiley-Interscience, 1, 234-286, 1985.
4.Fu Z., Fan Y., and Fan Z., Temperature-structure Dependence of Poly(1-octene-co-t-butyl acrylate) Prepared by Conventional Free Radical Polymerization, Iran. Polym. J., 20, 223-235, 2011.
5.Kumar K.R., Feroz S., and Rao P.R., Thermal and Di-electrical Properties of 1,11 Azobis (cyclohexanecarbonitrile) Initiated Nitrile Copolymer, Asian J. Res. Chem., 1, 58-63, 2008.
6.Bakhshi H., Zohuriaan-Mehr M.J., Bouhendi H., and Kabiri K., Emulsion Copolymerization of Butyl acrylate and Glycidyl Methacrylate:Determination of Monomer Reactivity Ratios, Iran. Polym. J., 19, 781-789, 2010.
7.Purushothaman M., Santhana Gopala Krishnan P., and Nayak S.K., Effect of Butyl Lactate Methacrylate Content on the Properties of Acrylic Acid Copolymers, Funct. Polym., 2016, DOI: 10.1134/S0965545X16030159,
8.Ziaee F. and Nekoomanesh M., Monomer Reactivity Ratios of styrene-Butyl Acrylate Copolymers at Low and High Conversions, Polymer, 39, 203-207, 1998.
9.Bradbury J. and Melville H., The Copolymerization of Butyl Acrylate and Styrene in Benzene Solution, Proceeding of the Royal Society, Proceeding of the Royal Society, Series A. Math. Phys. Eng. Sci., 222, 456-470, 1954.
10.Finemann M. and Ross S.D., The Trimer of o-Phthalonitrile, J. Polym. Sci., 5, 259-262, 1950.
11.Ezrielev A., Brokhina E., and Roskin E., Analytical Method for Calculating Copolymerization Constants, Vysokomol Soedin. A., 11, 1670-1680, 1969.
12.Kelen T. and Tudos F., A New Improved Linear Graphical Method for Determining Copolymerization Reactivity Ratios, React. Kinet. Catal. L., 1, 487-492, 1974.
13.Tudos F., Kelen T., Foldes-Berezsnich T., and Turcsanyi B., Analysis of the Linear Methods for Determining Copolymerization Reactivity Ratios. I. A New Improved Linear Graphic Method, J. Macromol. Sci.:Chem., 10, 1513-1540, 1976.
14.Joshi R. and Joshi S., A New Analytical Solution of the Binary Copolymer Composition Equation and Suggested Procedure for Deriving the Monomer Reactivity Ratios, J. Macromol. Sci-Chem., 5, 1329-1338, 1971.
15.Mao R. and Huglin M.B., A New Linear Method to Calculate Monomer Reactivity Ratios by Using High Conversion Copolymerization Data: Terminal Model, Polymer, 34, 1709-1715, 1993.
16.Habibi A., Vasheghani-Farahani E., Semsarzadeh M.A., and Sadaghiani K., A Generalized Least Square Model for the Determination of Monomer Reactivity Ratios in Free Radical Copolymerization Systems, Macromol. Theory Simul., 12, 184-195, 2003.
17.Habibi A., Vasheghani‐Farahani E., Semsarzadeh M., and Sadaghiani K., Estimation of Monomer Reactivity Ratios in Free‐Radical Solution Copolymerization of Lauryl Methacrylate–Isobutyl Methacrylate, J. Polym. Sci., Part A: Polym. Chem., 42, 112-129, 2004.
18.Habibi A., Vasheghani‐Farahani E., Semsarzadeh M., and Sadaghiani K., Monomer Reactivity Ratios for Lauryl Methacrylate–Isobutyl Methacrylate in Bulk Free Radical Copolymerization, Polym. Int., 52, 1434-1443, 2003.
19.Gauthier M., Carrozzella T., and Penlidis A., Sulfobetaine Zwitterionomers Based on n‐Butyl Acrylate and 2‐Ethoxyethyl Acrylate: Monomer Synthesis and Copolymerization Behavior, J. Polym. Sci., Part A: Polym. Chem., 40, 511-523, 2002.
20.Ashenagar S., Ziaee F., and Jalilian M., Calculation of Reactivity Ratios of Methacrylic Acid-Ethyl Acrylate Copolymer by On-Line Quantitative 1H NMR Spectroscopy, Iran. Polym. J., 22, 235-239, 2013.
21.Ashenagar S., Ziaee F., and Shabani I., Reactivity Ratio Determination of Styrene and 2-Ethylhexyl Acrylate by Least Squares Methods, Int. J. Plast. Technol., 19, 191-198, 2015.
22.Ziaee F. and Nekoomanesh M., Methods for Determination of Monomers Reactivity Ratios in Copolymers, Iran. Polym. J. Sci. Technol. (Persian), 8, 119-126, 1995.