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Heat Capacity and Other Thermodynamic Properties of Linear Macromolecules VI

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Heat Capacity and Other Thermodynamic Properties of Linear Macromolecules VI Heat Capacity and Other Thermodynamic Properties of Linear Macromolecules VI. Acrylic Polymers Cite as: Journal of Physical and Chemical Reference Data 11, 1065 (1982); https://doi.org/10.1063/1.555671 Published Online: 15 October 2009 Umesh Gaur, Suk-fai Lau, Brent B. Wunderlich, and Bernhard Wunderlich ARTICLES YOU MAY BE INTERESTED IN Heat Capacity and Other Thermodynamic Properties of Linear Macromolecules. V. Polystyrene Journal of Physical and Chemical Reference Data 11, 313 (1982); https:// doi.org/10.1063/1.555663 Heat Capacity and Other Thermodynamic Properties of Linear Macromolecules. VIII. Polyesters and Polyamides Journal of Physical and Chemical Reference Data 12, 65 (1983); https:// doi.org/10.1063/1.555678 Heat Capacity and Other Thermodynamic Properties of Linear Macromolecules. VII. Other Carbon Backbone Polymers Journal of Physical and Chemical Reference Data 12, 29 (1983); https:// doi.org/10.1063/1.555677 Journal of Physical and Chemical Reference Data 11, 1065 (1982); https://doi.org/10.1063/1.555671 11, 1065 © 1982 American Institute of Physics for the National Institute of Standards and Technology. Heat Capacity and Other Thermodynamic Properties of Linear Macromolecules VI. Acrylic Polymers Umesh Gaur, Suk-fai lau, Brent B. Wunderlich, and Bernhard Wunderlich Department of Chemistry, Rensselaer Polytechnic Institute, Troy, New York 12181 Heat capacity of poly(methyl methacrylate), polyacrylonitrile, poly(methyl acrylate), poly(ethyl acrylate), poly(n-butyl acrylate), poly(iso-butyl acrylate), poly(octadecyl acry­ late), poly(methacrylic acid), poly(ethyl methacrylate), poly(n-butyl methacrylate), po­ ly(iso-butyl methacrylate), poly{hexyl methacrylate), poly(dodecyl methacrylate), poly{oc­ tadecyl methacrylate) and polymethacrylamide is reviewed on the basis of measurements on 35 samples reported in the literature. A set of recommended data are derived for each a<.;ry Ii<.; pulyIIlt:r in tht: amorphous state. Enthalpy and entropy functions are calculated for poly(methyl methacrylate) and polyacrylonitrile. This is the sixth paper in a series of publications which will ultimately cover all heat capacity measurements on linear macro­ molecules. Key words: enthalpy; entropy; glass transition; heat capacity; linear macromolecule; polyacrylate; polyacryloni­ trile; polymethacrylamide; polymethacrylate; poly(methacrylic acid). Contents ~ag~ 1. Introduction .................... ....... .......... ......... .... ........ 1066 Table 6. Recommended thermodynamic data for 2. Heat Capacity of Acrylic Polymers ...................... 1066 glassy polyacrylonitrile............................ 1075 2.1. Introduction ..... ,......... , ....... ....... .......... ........... 1066 Table 7. Heat capacity measurements of poly- 2.2. Literature Data on Heat Capacity of Acrylic (methyl acrylate) ...................................... 1076 Polymers......................................................... 1068 Table 8. Heat capacity measurements of po- 2.3. Recommended Data on Heat Capacity and ly(ethyl acrylate) ...................................... 1076 Thermodynamic Functions of Acrylic Poly- Table 9. Heat capacity measurements of poly(n- mers................................................................ 1068 butyl acrylate) .......................................... 1077 2.3.1. Poly(methyl methacrylate) ................... 1068 Table 10. Heat capacity measurements of poly(iso- 2.3.2. Polyacrylonitrile................................... 1074 butyl acrylate) ....................... :.................. 1077 2.3.3. Other Acrylic Polymers ....................... 1074 Table 11. Heat capacity measurements of poly(oc­ 3. Conclusions ............................ ;.............................. 1087 tadecyl acrylate)....................................... 1077 4. References ~............................................................ 1088 Table 12. Heat capacity measurements of poly- (methacrylic acid) .................................... 1077 Table 13. Heat capacity measurements of po- List of Tables ly(ethyl methacrylate) .............................. 1078 Table 14. Heat capacity measurements of poly(n- Table 1. Acrylic polymers investigated in this butyl methacrylate).................................. 1078 study........................................................ 1067 Table 15. Heat capacity me.aSl1rements of poly(iso- Table 2. Investigations not included in this study. 1069 butyl methacrylate).................................. 1078 Table 3. Heat capacity measurements of poly­ Table 16. Heat capacity measurements of poly- (methyl methacrylate).............................. 1071 (hexyl methacrylate) ................................ 1079 Table 4. Recommended thermodynamic data for Table 17. Heat capacity measurements of poly(do- amorphous poly(methyl methacrylate).... 1072 decyl methacrylate) ................................. 1079 Table 5. Heat capacity measurements of polyacry- Table 18. Heat capacity measurements of poly(oc- lonitrile .................................................... 1074 tade<.;yl methacrylatt:} .............................. 1079 Table 19. Heat capacity measurements of poly­ methacrylamide....................................... 1079 Table 20. Recommended heat capacity data for ® 1982 by the U.S. Secretary of Commerce on behalf of the United States. glassy polyacrylates ...... ............. ............... 1080 This copyright is assigned to the American Institute of Physics and the American Chemical Society. Table 21. Recommended heat capacity data for Reprints available from ACS; see Reprint List at back of issue. molten polyacrylates ................... ........ .... 1081 0041-2689/82/041065-25/$06.00 1065 J. Phys. Chem. Ref. Data, Vol. 11, No.4, 1982 1066 GAUR ETAl. Page Page Table 22. Recommended heat capacity data for Table lOA. Heat capacity of poly(octadecyI acry­ glassy polymethacrylates.................... ..... 1082 late) Table 23. Recommended heat capacity data for Table IIA. Heat capacity of various poly(metha­ molten polymethacrylates ....................... 1083 crylic acid)s Table 24. Results of curve fitting literature data on Table 12A. Heat capacity of various poly(ethyl heat capacity of acrylic polymers to de- methacrylate)s rive recommended data ........................... 1084 Table 13A. Heat capacity of various poly(n-butyl Table 25. Equations cited in table 24 ...................... 1085 methacrylate)s Table 26. Heat capacity change at the glass transi- Table 14A. Heat capacity of poly(iso-butyl metha­ tion temperature...................................... 1087 crylate) Table 15A. Jl~Clt capacity of poly(hexyl methacry­ Ust of Tables Deposited in PAPS1 late) Table 16A. Heat capacity of poly(dodecyl metha­ Table IA. Heat capacity of various poly(methyl crylate) methacrylate)s at low temperature Table 17A_ Heat capacity of poly(octadecyl metha­ Table 2A. Heat capacity of various glassy poly­ crylate) (methyl methacrylate)s Table 18A. Heat capacity of polymethacrylamide Table 3A. Heat capacity of various molten poly­ (methyl methacrylate)s Table 4A. Heat capacity of various polyacryloni­ triles List of figures Table SA. Heat capacity of various glassy poly­ (methyl acrylate)s Figure I. Recommended data on heat capacity of Table 6A. Heat capacity of various molten poly­ polyacrylates ............................................ 1086 (methyl acrylate)s Figure 2. Recommended data on heat capacity of Table 7A. Heat capacity of various poly(ethyl polymethacrylates.................................... 1086 acrylate)s J1:gure -3~Reoommended data on heat capaCity of Table 8A. Heat capacity of various poly(n-butyl acrylic polymers with large side groups.. 1086 acrylate)s Figure 4. Recommended heat capacity data for po­ Table 9A. Heat capacity of poly(iso-butyl acry- lyacrylonitrile, poly(meth~crylic acid) late) . and polymethacrylamide ... ...................... 1086 1. Introduction isotactic polymers have not been reported. The acrylic poly­ mers which have been analyzed in this study are listed in This is the sixth paper in a series of discussions on the table 1 [6,7,8]. For acrylic polymers with long side chain he~t capacity oflinear macromolecules. In the earlier papers (more than 10-12 carbon atoms), side chain crystallinity is [1-5F. the heat capacity of selenium. polyethylene. polypro­ observed [8,9]. The glass transition temperature of this kiml pylene, polystyrene and various types of polyoxides have of polymer with side groups usually decreases as the length been analyzed. This paper deals with acrylic polymers. In of the side group increases. Reimschuessel [8] has derived subsequent papers heat capacity of all other polymers with several empirical equations which correlate the glass transi­ carbon backbone, polyamides, polyesters and polymers con­ tion temperature with the number of carbon atoms in the taining aromatic groups and/or inorganic chain atoms will side chain. It was found that the glass transition temperature be evaluated. decreases monotonically as the length of the alkyl side-chain increases toward a critical length. The critical length is dif­ 2. Heat Capacity of Acrylic Polymers ferent for different kinds of polymer backbones (e.g., 9 for poly(alkly acrylate) and 12 for poly(alkyl methacrylate). 2.1. Introduction Reimschuessel [8] suggested that the decrease in glass transi- Acrylic polymers are usually atactic and thus amor­ . tion temperature is due to the interaction of the backbone phous over the whole temperature region. Heat capacities of and the side
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